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/** | |
* @license | |
* Copyright 2019 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
const NODE_MODE$1 = false; | |
// Allows minifiers to rename references to globalThis | |
const global$2 = globalThis; | |
/** | |
* Whether the current browser supports `adoptedStyleSheets`. | |
*/ | |
const supportsAdoptingStyleSheets = global$2.ShadowRoot && | |
(global$2.ShadyCSS === undefined || global$2.ShadyCSS.nativeShadow) && | |
'adoptedStyleSheets' in Document.prototype && | |
'replace' in CSSStyleSheet.prototype; | |
const constructionToken = Symbol(); | |
const cssTagCache = new WeakMap(); | |
/** | |
* A container for a string of CSS text, that may be used to create a CSSStyleSheet. | |
* | |
* CSSResult is the return value of `css`-tagged template literals and | |
* `unsafeCSS()`. In order to ensure that CSSResults are only created via the | |
* `css` tag and `unsafeCSS()`, CSSResult cannot be constructed directly. | |
*/ | |
class CSSResult { | |
constructor(cssText, strings, safeToken) { | |
// This property needs to remain unminified. | |
this['_$cssResult$'] = true; | |
if (safeToken !== constructionToken) { | |
throw new Error('CSSResult is not constructable. Use `unsafeCSS` or `css` instead.'); | |
} | |
this.cssText = cssText; | |
this._strings = strings; | |
} | |
// This is a getter so that it's lazy. In practice, this means stylesheets | |
// are not created until the first element instance is made. | |
get styleSheet() { | |
// If `supportsAdoptingStyleSheets` is true then we assume CSSStyleSheet is | |
// constructable. | |
let styleSheet = this._styleSheet; | |
const strings = this._strings; | |
if (supportsAdoptingStyleSheets && styleSheet === undefined) { | |
const cacheable = strings !== undefined && strings.length === 1; | |
if (cacheable) { | |
styleSheet = cssTagCache.get(strings); | |
} | |
if (styleSheet === undefined) { | |
(this._styleSheet = styleSheet = new CSSStyleSheet()).replaceSync(this.cssText); | |
if (cacheable) { | |
cssTagCache.set(strings, styleSheet); | |
} | |
} | |
} | |
return styleSheet; | |
} | |
toString() { | |
return this.cssText; | |
} | |
} | |
const textFromCSSResult = (value) => { | |
// This property needs to remain unminified. | |
if (value['_$cssResult$'] === true) { | |
return value.cssText; | |
} | |
else if (typeof value === 'number') { | |
return value; | |
} | |
else { | |
throw new Error(`Value passed to 'css' function must be a 'css' function result: ` + | |
`${value}. Use 'unsafeCSS' to pass non-literal values, but take care ` + | |
`to ensure page security.`); | |
} | |
}; | |
/** | |
* Wrap a value for interpolation in a {@linkcode css} tagged template literal. | |
* | |
* This is unsafe because untrusted CSS text can be used to phone home | |
* or exfiltrate data to an attacker controlled site. Take care to only use | |
* this with trusted input. | |
*/ | |
const unsafeCSS = (value) => new CSSResult(typeof value === 'string' ? value : String(value), undefined, constructionToken); | |
/** | |
* A template literal tag which can be used with LitElement's | |
* {@linkcode LitElement.styles} property to set element styles. | |
* | |
* For security reasons, only literal string values and number may be used in | |
* embedded expressions. To incorporate non-literal values {@linkcode unsafeCSS} | |
* may be used inside an expression. | |
*/ | |
const css = (strings, ...values) => { | |
const cssText = strings.length === 1 | |
? strings[0] | |
: values.reduce((acc, v, idx) => acc + textFromCSSResult(v) + strings[idx + 1], strings[0]); | |
return new CSSResult(cssText, strings, constructionToken); | |
}; | |
/** | |
* Applies the given styles to a `shadowRoot`. When Shadow DOM is | |
* available but `adoptedStyleSheets` is not, styles are appended to the | |
* `shadowRoot` to [mimic spec behavior](https://wicg.github.io/construct-stylesheets/#using-constructed-stylesheets). | |
* Note, when shimming is used, any styles that are subsequently placed into | |
* the shadowRoot should be placed *before* any shimmed adopted styles. This | |
* will match spec behavior that gives adopted sheets precedence over styles in | |
* shadowRoot. | |
*/ | |
const adoptStyles = (renderRoot, styles) => { | |
if (supportsAdoptingStyleSheets) { | |
renderRoot.adoptedStyleSheets = styles.map((s) => s instanceof CSSStyleSheet ? s : s.styleSheet); | |
} | |
else { | |
for (const s of styles) { | |
const style = document.createElement('style'); | |
// eslint-disable-next-line @typescript-eslint/no-explicit-any | |
const nonce = global$2['litNonce']; | |
if (nonce !== undefined) { | |
style.setAttribute('nonce', nonce); | |
} | |
style.textContent = s.cssText; | |
renderRoot.appendChild(style); | |
} | |
} | |
}; | |
const cssResultFromStyleSheet = (sheet) => { | |
let cssText = ''; | |
for (const rule of sheet.cssRules) { | |
cssText += rule.cssText; | |
} | |
return unsafeCSS(cssText); | |
}; | |
const getCompatibleStyle = supportsAdoptingStyleSheets || | |
(NODE_MODE$1 ) | |
? (s) => s | |
: (s) => s instanceof CSSStyleSheet ? cssResultFromStyleSheet(s) : s; | |
/** | |
* @license | |
* Copyright 2017 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
// TODO (justinfagnani): Add `hasOwn` here when we ship ES2022 | |
const { is, defineProperty, getOwnPropertyDescriptor, getOwnPropertyNames, getOwnPropertySymbols, getPrototypeOf, } = Object; | |
// Lets a minifier replace globalThis references with a minified name | |
const global$1 = globalThis; | |
const trustedTypes$1 = global$1 | |
.trustedTypes; | |
// Temporary workaround for https://crbug.com/993268 | |
// Currently, any attribute starting with "on" is considered to be a | |
// TrustedScript source. Such boolean attributes must be set to the equivalent | |
// trusted emptyScript value. | |
const emptyStringForBooleanAttribute = trustedTypes$1 | |
? trustedTypes$1.emptyScript | |
: ''; | |
const polyfillSupport$2 = global$1.reactiveElementPolyfillSupport; | |
/** | |
* Useful for visualizing and logging insights into what the Lit template system is doing. | |
* | |
* Compiled out of prod mode builds. | |
*/ | |
const debugLogEvent = undefined; | |
/* | |
* When using Closure Compiler, JSCompiler_renameProperty(property, object) is | |
* replaced at compile time by the munged name for object[property]. We cannot | |
* alias this function, so we have to use a small shim that has the same | |
* behavior when not compiling. | |
*/ | |
/*@__INLINE__*/ | |
const JSCompiler_renameProperty$1 = (prop, _obj) => prop; | |
const defaultConverter = { | |
toAttribute(value, type) { | |
switch (type) { | |
case Boolean: | |
value = value ? emptyStringForBooleanAttribute : null; | |
break; | |
case Object: | |
case Array: | |
// if the value is `null` or `undefined` pass this through | |
// to allow removing/no change behavior. | |
value = value == null ? value : JSON.stringify(value); | |
break; | |
} | |
return value; | |
}, | |
fromAttribute(value, type) { | |
let fromValue = value; | |
switch (type) { | |
case Boolean: | |
fromValue = value !== null; | |
break; | |
case Number: | |
fromValue = value === null ? null : Number(value); | |
break; | |
case Object: | |
case Array: | |
// Do *not* generate exception when invalid JSON is set as elements | |
// don't normally complain on being mis-configured. | |
// TODO(sorvell): Do generate exception in *dev mode*. | |
try { | |
// Assert to adhere to Bazel's "must type assert JSON parse" rule. | |
fromValue = JSON.parse(value); | |
} | |
catch (e) { | |
fromValue = null; | |
} | |
break; | |
} | |
return fromValue; | |
}, | |
}; | |
/** | |
* Change function that returns true if `value` is different from `oldValue`. | |
* This method is used as the default for a property's `hasChanged` function. | |
*/ | |
const notEqual = (value, old) => !is(value, old); | |
const defaultPropertyDeclaration = { | |
attribute: true, | |
type: String, | |
converter: defaultConverter, | |
reflect: false, | |
hasChanged: notEqual, | |
}; | |
// Ensure metadata is enabled. TypeScript does not polyfill | |
// Symbol.metadata, so we must ensure that it exists. | |
Symbol.metadata ??= Symbol('metadata'); | |
// Map from a class's metadata object to property options | |
// Note that we must use nullish-coalescing assignment so that we only use one | |
// map even if we load multiple version of this module. | |
global$1.litPropertyMetadata ??= new WeakMap(); | |
/** | |
* Base element class which manages element properties and attributes. When | |
* properties change, the `update` method is asynchronously called. This method | |
* should be supplied by subclasses to render updates as desired. | |
* @noInheritDoc | |
*/ | |
class ReactiveElement | |
// In the Node build, this `extends` clause will be substituted with | |
// `(globalThis.HTMLElement ?? HTMLElement)`. | |
// | |
// This way, we will first prefer any global `HTMLElement` polyfill that the | |
// user has assigned, and then fall back to the `HTMLElement` shim which has | |
// been imported (see note at the top of this file about how this import is | |
// generated by Rollup). Note that the `HTMLElement` variable has been | |
// shadowed by this import, so it no longer refers to the global. | |
extends HTMLElement { | |
/** | |
* Adds an initializer function to the class that is called during instance | |
* construction. | |
* | |
* This is useful for code that runs against a `ReactiveElement` | |
* subclass, such as a decorator, that needs to do work for each | |
* instance, such as setting up a `ReactiveController`. | |
* | |
* ```ts | |
* const myDecorator = (target: typeof ReactiveElement, key: string) => { | |
* target.addInitializer((instance: ReactiveElement) => { | |
* // This is run during construction of the element | |
* new MyController(instance); | |
* }); | |
* } | |
* ``` | |
* | |
* Decorating a field will then cause each instance to run an initializer | |
* that adds a controller: | |
* | |
* ```ts | |
* class MyElement extends LitElement { | |
* @myDecorator foo; | |
* } | |
* ``` | |
* | |
* Initializers are stored per-constructor. Adding an initializer to a | |
* subclass does not add it to a superclass. Since initializers are run in | |
* constructors, initializers will run in order of the class hierarchy, | |
* starting with superclasses and progressing to the instance's class. | |
* | |
* @nocollapse | |
*/ | |
static addInitializer(initializer) { | |
this.__prepare(); | |
(this._initializers ??= []).push(initializer); | |
} | |
/** | |
* Returns a list of attributes corresponding to the registered properties. | |
* @nocollapse | |
* @category attributes | |
*/ | |
static get observedAttributes() { | |
// Ensure we've created all properties | |
this.finalize(); | |
// this.__attributeToPropertyMap is only undefined after finalize() in | |
// ReactiveElement itself. ReactiveElement.observedAttributes is only | |
// accessed with ReactiveElement as the receiver when a subclass or mixin | |
// calls super.observedAttributes | |
return (this.__attributeToPropertyMap && [...this.__attributeToPropertyMap.keys()]); | |
} | |
/** | |
* Creates a property accessor on the element prototype if one does not exist | |
* and stores a {@linkcode PropertyDeclaration} for the property with the | |
* given options. The property setter calls the property's `hasChanged` | |
* property option or uses a strict identity check to determine whether or not | |
* to request an update. | |
* | |
* This method may be overridden to customize properties; however, | |
* when doing so, it's important to call `super.createProperty` to ensure | |
* the property is setup correctly. This method calls | |
* `getPropertyDescriptor` internally to get a descriptor to install. | |
* To customize what properties do when they are get or set, override | |
* `getPropertyDescriptor`. To customize the options for a property, | |
* implement `createProperty` like this: | |
* | |
* ```ts | |
* static createProperty(name, options) { | |
* options = Object.assign(options, {myOption: true}); | |
* super.createProperty(name, options); | |
* } | |
* ``` | |
* | |
* @nocollapse | |
* @category properties | |
*/ | |
static createProperty(name, options = defaultPropertyDeclaration) { | |
// If this is a state property, force the attribute to false. | |
if (options.state) { | |
options.attribute = false; | |
} | |
this.__prepare(); | |
this.elementProperties.set(name, options); | |
if (!options.noAccessor) { | |
const key = Symbol(); | |
const descriptor = this.getPropertyDescriptor(name, key, options); | |
if (descriptor !== undefined) { | |
defineProperty(this.prototype, name, descriptor); | |
} | |
} | |
} | |
/** | |
* Returns a property descriptor to be defined on the given named property. | |
* If no descriptor is returned, the property will not become an accessor. | |
* For example, | |
* | |
* ```ts | |
* class MyElement extends LitElement { | |
* static getPropertyDescriptor(name, key, options) { | |
* const defaultDescriptor = | |
* super.getPropertyDescriptor(name, key, options); | |
* const setter = defaultDescriptor.set; | |
* return { | |
* get: defaultDescriptor.get, | |
* set(value) { | |
* setter.call(this, value); | |
* // custom action. | |
* }, | |
* configurable: true, | |
* enumerable: true | |
* } | |
* } | |
* } | |
* ``` | |
* | |
* @nocollapse | |
* @category properties | |
*/ | |
static getPropertyDescriptor(name, key, options) { | |
const { get, set } = getOwnPropertyDescriptor(this.prototype, name) ?? { | |
get() { | |
return this[key]; | |
}, | |
set(v) { | |
this[key] = v; | |
}, | |
}; | |
return { | |
get() { | |
return get?.call(this); | |
}, | |
set(value) { | |
const oldValue = get?.call(this); | |
set.call(this, value); | |
this.requestUpdate(name, oldValue, options); | |
}, | |
configurable: true, | |
enumerable: true, | |
}; | |
} | |
/** | |
* Returns the property options associated with the given property. | |
* These options are defined with a `PropertyDeclaration` via the `properties` | |
* object or the `@property` decorator and are registered in | |
* `createProperty(...)`. | |
* | |
* Note, this method should be considered "final" and not overridden. To | |
* customize the options for a given property, override | |
* {@linkcode createProperty}. | |
* | |
* @nocollapse | |
* @final | |
* @category properties | |
*/ | |
static getPropertyOptions(name) { | |
return this.elementProperties.get(name) ?? defaultPropertyDeclaration; | |
} | |
/** | |
* Initializes static own properties of the class used in bookkeeping | |
* for element properties, initializers, etc. | |
* | |
* Can be called multiple times by code that needs to ensure these | |
* properties exist before using them. | |
* | |
* This method ensures the superclass is finalized so that inherited | |
* property metadata can be copied down. | |
* @nocollapse | |
*/ | |
static __prepare() { | |
if (this.hasOwnProperty(JSCompiler_renameProperty$1('elementProperties'))) { | |
// Already prepared | |
return; | |
} | |
// Finalize any superclasses | |
const superCtor = getPrototypeOf(this); | |
superCtor.finalize(); | |
// Create own set of initializers for this class if any exist on the | |
// superclass and copy them down. Note, for a small perf boost, avoid | |
// creating initializers unless needed. | |
if (superCtor._initializers !== undefined) { | |
this._initializers = [...superCtor._initializers]; | |
} | |
// Initialize elementProperties from the superclass | |
this.elementProperties = new Map(superCtor.elementProperties); | |
} | |
/** | |
* Finishes setting up the class so that it's ready to be registered | |
* as a custom element and instantiated. | |
* | |
* This method is called by the ReactiveElement.observedAttributes getter. | |
* If you override the observedAttributes getter, you must either call | |
* super.observedAttributes to trigger finalization, or call finalize() | |
* yourself. | |
* | |
* @nocollapse | |
*/ | |
static finalize() { | |
if (this.hasOwnProperty(JSCompiler_renameProperty$1('finalized'))) { | |
return; | |
} | |
this.finalized = true; | |
this.__prepare(); | |
// Create properties from the static properties block: | |
if (this.hasOwnProperty(JSCompiler_renameProperty$1('properties'))) { | |
const props = this.properties; | |
const propKeys = [ | |
...getOwnPropertyNames(props), | |
...getOwnPropertySymbols(props), | |
]; | |
for (const p of propKeys) { | |
this.createProperty(p, props[p]); | |
} | |
} | |
// Create properties from standard decorator metadata: | |
const metadata = this[Symbol.metadata]; | |
if (metadata !== null) { | |
const properties = litPropertyMetadata.get(metadata); | |
if (properties !== undefined) { | |
for (const [p, options] of properties) { | |
this.elementProperties.set(p, options); | |
} | |
} | |
} | |
// Create the attribute-to-property map | |
this.__attributeToPropertyMap = new Map(); | |
for (const [p, options] of this.elementProperties) { | |
const attr = this.__attributeNameForProperty(p, options); | |
if (attr !== undefined) { | |
this.__attributeToPropertyMap.set(attr, p); | |
} | |
} | |
this.elementStyles = this.finalizeStyles(this.styles); | |
} | |
/** | |
* Takes the styles the user supplied via the `static styles` property and | |
* returns the array of styles to apply to the element. | |
* Override this method to integrate into a style management system. | |
* | |
* Styles are deduplicated preserving the _last_ instance in the list. This | |
* is a performance optimization to avoid duplicated styles that can occur | |
* especially when composing via subclassing. The last item is kept to try | |
* to preserve the cascade order with the assumption that it's most important | |
* that last added styles override previous styles. | |
* | |
* @nocollapse | |
* @category styles | |
*/ | |
static finalizeStyles(styles) { | |
const elementStyles = []; | |
if (Array.isArray(styles)) { | |
// Dedupe the flattened array in reverse order to preserve the last items. | |
// Casting to Array<unknown> works around TS error that | |
// appears to come from trying to flatten a type CSSResultArray. | |
const set = new Set(styles.flat(Infinity).reverse()); | |
// Then preserve original order by adding the set items in reverse order. | |
for (const s of set) { | |
elementStyles.unshift(getCompatibleStyle(s)); | |
} | |
} | |
else if (styles !== undefined) { | |
elementStyles.push(getCompatibleStyle(styles)); | |
} | |
return elementStyles; | |
} | |
/** | |
* Returns the property name for the given attribute `name`. | |
* @nocollapse | |
*/ | |
static __attributeNameForProperty(name, options) { | |
const attribute = options.attribute; | |
return attribute === false | |
? undefined | |
: typeof attribute === 'string' | |
? attribute | |
: typeof name === 'string' | |
? name.toLowerCase() | |
: undefined; | |
} | |
constructor() { | |
super(); | |
this.__instanceProperties = undefined; | |
/** | |
* True if there is a pending update as a result of calling `requestUpdate()`. | |
* Should only be read. | |
* @category updates | |
*/ | |
this.isUpdatePending = false; | |
/** | |
* Is set to `true` after the first update. The element code cannot assume | |
* that `renderRoot` exists before the element `hasUpdated`. | |
* @category updates | |
*/ | |
this.hasUpdated = false; | |
/** | |
* Name of currently reflecting property | |
*/ | |
this.__reflectingProperty = null; | |
this.__initialize(); | |
} | |
/** | |
* Internal only override point for customizing work done when elements | |
* are constructed. | |
*/ | |
__initialize() { | |
this.__updatePromise = new Promise((res) => (this.enableUpdating = res)); | |
this._$changedProperties = new Map(); | |
// This enqueues a microtask that ust run before the first update, so it | |
// must be called before requestUpdate() | |
this.__saveInstanceProperties(); | |
// ensures first update will be caught by an early access of | |
// `updateComplete` | |
this.requestUpdate(); | |
this.constructor._initializers?.forEach((i) => i(this)); | |
} | |
/** | |
* Registers a `ReactiveController` to participate in the element's reactive | |
* update cycle. The element automatically calls into any registered | |
* controllers during its lifecycle callbacks. | |
* | |
* If the element is connected when `addController()` is called, the | |
* controller's `hostConnected()` callback will be immediately called. | |
* @category controllers | |
*/ | |
addController(controller) { | |
(this.__controllers ??= new Set()).add(controller); | |
// If a controller is added after the element has been connected, | |
// call hostConnected. Note, re-using existence of `renderRoot` here | |
// (which is set in connectedCallback) to avoid the need to track a | |
// first connected state. | |
if (this.renderRoot !== undefined && this.isConnected) { | |
controller.hostConnected?.(); | |
} | |
} | |
/** | |
* Removes a `ReactiveController` from the element. | |
* @category controllers | |
*/ | |
removeController(controller) { | |
this.__controllers?.delete(controller); | |
} | |
/** | |
* Fixes any properties set on the instance before upgrade time. | |
* Otherwise these would shadow the accessor and break these properties. | |
* The properties are stored in a Map which is played back after the | |
* constructor runs. Note, on very old versions of Safari (<=9) or Chrome | |
* (<=41), properties created for native platform properties like (`id` or | |
* `name`) may not have default values set in the element constructor. On | |
* these browsers native properties appear on instances and therefore their | |
* default value will overwrite any element default (e.g. if the element sets | |
* this.id = 'id' in the constructor, the 'id' will become '' since this is | |
* the native platform default). | |
*/ | |
__saveInstanceProperties() { | |
const instanceProperties = new Map(); | |
const elementProperties = this.constructor | |
.elementProperties; | |
for (const p of elementProperties.keys()) { | |
if (this.hasOwnProperty(p)) { | |
instanceProperties.set(p, this[p]); | |
delete this[p]; | |
} | |
} | |
if (instanceProperties.size > 0) { | |
this.__instanceProperties = instanceProperties; | |
} | |
} | |
/** | |
* Returns the node into which the element should render and by default | |
* creates and returns an open shadowRoot. Implement to customize where the | |
* element's DOM is rendered. For example, to render into the element's | |
* childNodes, return `this`. | |
* | |
* @return Returns a node into which to render. | |
* @category rendering | |
*/ | |
createRenderRoot() { | |
const renderRoot = this.shadowRoot ?? | |
this.attachShadow(this.constructor.shadowRootOptions); | |
adoptStyles(renderRoot, this.constructor.elementStyles); | |
return renderRoot; | |
} | |
/** | |
* On first connection, creates the element's renderRoot, sets up | |
* element styling, and enables updating. | |
* @category lifecycle | |
*/ | |
connectedCallback() { | |
// Create renderRoot before controllers `hostConnected` | |
this.renderRoot ??= | |
this.createRenderRoot(); | |
this.enableUpdating(true); | |
this.__controllers?.forEach((c) => c.hostConnected?.()); | |
} | |
/** | |
* Note, this method should be considered final and not overridden. It is | |
* overridden on the element instance with a function that triggers the first | |
* update. | |
* @category updates | |
*/ | |
enableUpdating(_requestedUpdate) { } | |
/** | |
* Allows for `super.disconnectedCallback()` in extensions while | |
* reserving the possibility of making non-breaking feature additions | |
* when disconnecting at some point in the future. | |
* @category lifecycle | |
*/ | |
disconnectedCallback() { | |
this.__controllers?.forEach((c) => c.hostDisconnected?.()); | |
} | |
/** | |
* Synchronizes property values when attributes change. | |
* | |
* Specifically, when an attribute is set, the corresponding property is set. | |
* You should rarely need to implement this callback. If this method is | |
* overridden, `super.attributeChangedCallback(name, _old, value)` must be | |
* called. | |
* | |
* See [using the lifecycle callbacks](https://developer.mozilla.org/en-US/docs/Web/Web_Components/Using_custom_elements#using_the_lifecycle_callbacks) | |
* on MDN for more information about the `attributeChangedCallback`. | |
* @category attributes | |
*/ | |
attributeChangedCallback(name, _old, value) { | |
this._$attributeToProperty(name, value); | |
} | |
__propertyToAttribute(name, value) { | |
const elemProperties = this.constructor.elementProperties; | |
const options = elemProperties.get(name); | |
const attr = this.constructor.__attributeNameForProperty(name, options); | |
if (attr !== undefined && options.reflect === true) { | |
const converter = options.converter?.toAttribute !== | |
undefined | |
? options.converter | |
: defaultConverter; | |
const attrValue = converter.toAttribute(value, options.type); | |
// Track if the property is being reflected to avoid | |
// setting the property again via `attributeChangedCallback`. Note: | |
// 1. this takes advantage of the fact that the callback is synchronous. | |
// 2. will behave incorrectly if multiple attributes are in the reaction | |
// stack at time of calling. However, since we process attributes | |
// in `update` this should not be possible (or an extreme corner case | |
// that we'd like to discover). | |
// mark state reflecting | |
this.__reflectingProperty = name; | |
if (attrValue == null) { | |
this.removeAttribute(attr); | |
} | |
else { | |
this.setAttribute(attr, attrValue); | |
} | |
// mark state not reflecting | |
this.__reflectingProperty = null; | |
} | |
} | |
/** @internal */ | |
_$attributeToProperty(name, value) { | |
const ctor = this.constructor; | |
// Note, hint this as an `AttributeMap` so closure clearly understands | |
// the type; it has issues with tracking types through statics | |
const propName = ctor.__attributeToPropertyMap.get(name); | |
// Use tracking info to avoid reflecting a property value to an attribute | |
// if it was just set because the attribute changed. | |
if (propName !== undefined && this.__reflectingProperty !== propName) { | |
const options = ctor.getPropertyOptions(propName); | |
const converter = typeof options.converter === 'function' | |
? { fromAttribute: options.converter } | |
: options.converter?.fromAttribute !== undefined | |
? options.converter | |
: defaultConverter; | |
// mark state reflecting | |
this.__reflectingProperty = propName; | |
this[propName] = converter.fromAttribute(value, options.type | |
// eslint-disable-next-line @typescript-eslint/no-explicit-any | |
); | |
// mark state not reflecting | |
this.__reflectingProperty = null; | |
} | |
} | |
/** | |
* Requests an update which is processed asynchronously. This should be called | |
* when an element should update based on some state not triggered by setting | |
* a reactive property. In this case, pass no arguments. It should also be | |
* called when manually implementing a property setter. In this case, pass the | |
* property `name` and `oldValue` to ensure that any configured property | |
* options are honored. | |
* | |
* @param name name of requesting property | |
* @param oldValue old value of requesting property | |
* @param options property options to use instead of the previously | |
* configured options | |
* @category updates | |
*/ | |
requestUpdate(name, oldValue, options) { | |
// If we have a property key, perform property update steps. | |
if (name !== undefined) { | |
options ??= this.constructor.getPropertyOptions(name); | |
const hasChanged = options.hasChanged ?? notEqual; | |
const newValue = this[name]; | |
if (hasChanged(newValue, oldValue)) { | |
this._$changeProperty(name, oldValue, options); | |
} | |
else { | |
// Abort the request if the property should not be considered changed. | |
return; | |
} | |
} | |
if (this.isUpdatePending === false) { | |
this.__updatePromise = this.__enqueueUpdate(); | |
} | |
} | |
/** | |
* @internal | |
*/ | |
_$changeProperty(name, oldValue, options) { | |
// TODO (justinfagnani): Create a benchmark of Map.has() + Map.set( | |
// vs just Map.set() | |
if (!this._$changedProperties.has(name)) { | |
this._$changedProperties.set(name, oldValue); | |
} | |
// Add to reflecting properties set. | |
// Note, it's important that every change has a chance to add the | |
// property to `__reflectingProperties`. This ensures setting | |
// attribute + property reflects correctly. | |
if (options.reflect === true && this.__reflectingProperty !== name) { | |
(this.__reflectingProperties ??= new Set()).add(name); | |
} | |
} | |
/** | |
* Sets up the element to asynchronously update. | |
*/ | |
async __enqueueUpdate() { | |
this.isUpdatePending = true; | |
try { | |
// Ensure any previous update has resolved before updating. | |
// This `await` also ensures that property changes are batched. | |
await this.__updatePromise; | |
} | |
catch (e) { | |
// Refire any previous errors async so they do not disrupt the update | |
// cycle. Errors are refired so developers have a chance to observe | |
// them, and this can be done by implementing | |
// `window.onunhandledrejection`. | |
Promise.reject(e); | |
} | |
const result = this.scheduleUpdate(); | |
// If `scheduleUpdate` returns a Promise, we await it. This is done to | |
// enable coordinating updates with a scheduler. Note, the result is | |
// checked to avoid delaying an additional microtask unless we need to. | |
if (result != null) { | |
await result; | |
} | |
return !this.isUpdatePending; | |
} | |
/** | |
* Schedules an element update. You can override this method to change the | |
* timing of updates by returning a Promise. The update will await the | |
* returned Promise, and you should resolve the Promise to allow the update | |
* to proceed. If this method is overridden, `super.scheduleUpdate()` | |
* must be called. | |
* | |
* For instance, to schedule updates to occur just before the next frame: | |
* | |
* ```ts | |
* override protected async scheduleUpdate(): Promise<unknown> { | |
* await new Promise((resolve) => requestAnimationFrame(() => resolve())); | |
* super.scheduleUpdate(); | |
* } | |
* ``` | |
* @category updates | |
*/ | |
scheduleUpdate() { | |
const result = this.performUpdate(); | |
return result; | |
} | |
/** | |
* Performs an element update. Note, if an exception is thrown during the | |
* update, `firstUpdated` and `updated` will not be called. | |
* | |
* Call `performUpdate()` to immediately process a pending update. This should | |
* generally not be needed, but it can be done in rare cases when you need to | |
* update synchronously. | |
* | |
* @category updates | |
*/ | |
performUpdate() { | |
// Abort any update if one is not pending when this is called. | |
// This can happen if `performUpdate` is called early to "flush" | |
// the update. | |
if (!this.isUpdatePending) { | |
return; | |
} | |
debugLogEvent?.({ kind: 'update' }); | |
if (!this.hasUpdated) { | |
// Create renderRoot before first update. This occurs in `connectedCallback` | |
// but is done here to support out of tree calls to `enableUpdating`/`performUpdate`. | |
this.renderRoot ??= | |
this.createRenderRoot(); | |
// Mixin instance properties once, if they exist. | |
if (this.__instanceProperties) { | |
// TODO (justinfagnani): should we use the stored value? Could a new value | |
// have been set since we stored the own property value? | |
for (const [p, value] of this.__instanceProperties) { | |
this[p] = value; | |
} | |
this.__instanceProperties = undefined; | |
} | |
// Trigger initial value reflection and populate the initial | |
// changedProperties map, but only for the case of experimental | |
// decorators on accessors, which will not have already populated the | |
// changedProperties map. We can't know if these accessors had | |
// initializers, so we just set them anyway - a difference from | |
// experimental decorators on fields and standard decorators on | |
// auto-accessors. | |
// For context why experimentalDecorators with auto accessors are handled | |
// specifically also see: | |
// https://github.com/lit/lit/pull/4183#issuecomment-1711959635 | |
const elementProperties = this.constructor | |
.elementProperties; | |
if (elementProperties.size > 0) { | |
for (const [p, options] of elementProperties) { | |
if (options.wrapped === true && | |
!this._$changedProperties.has(p) && | |
this[p] !== undefined) { | |
this._$changeProperty(p, this[p], options); | |
} | |
} | |
} | |
} | |
let shouldUpdate = false; | |
const changedProperties = this._$changedProperties; | |
try { | |
shouldUpdate = this.shouldUpdate(changedProperties); | |
if (shouldUpdate) { | |
this.willUpdate(changedProperties); | |
this.__controllers?.forEach((c) => c.hostUpdate?.()); | |
this.update(changedProperties); | |
} | |
else { | |
this.__markUpdated(); | |
} | |
} | |
catch (e) { | |
// Prevent `firstUpdated` and `updated` from running when there's an | |
// update exception. | |
shouldUpdate = false; | |
// Ensure element can accept additional updates after an exception. | |
this.__markUpdated(); | |
throw e; | |
} | |
// The update is no longer considered pending and further updates are now allowed. | |
if (shouldUpdate) { | |
this._$didUpdate(changedProperties); | |
} | |
} | |
/** | |
* Invoked before `update()` to compute values needed during the update. | |
* | |
* Implement `willUpdate` to compute property values that depend on other | |
* properties and are used in the rest of the update process. | |
* | |
* ```ts | |
* willUpdate(changedProperties) { | |
* // only need to check changed properties for an expensive computation. | |
* if (changedProperties.has('firstName') || changedProperties.has('lastName')) { | |
* this.sha = computeSHA(`${this.firstName} ${this.lastName}`); | |
* } | |
* } | |
* | |
* render() { | |
* return html`SHA: ${this.sha}`; | |
* } | |
* ``` | |
* | |
* @category updates | |
*/ | |
willUpdate(_changedProperties) { } | |
// Note, this is an override point for polyfill-support. | |
// @internal | |
_$didUpdate(changedProperties) { | |
this.__controllers?.forEach((c) => c.hostUpdated?.()); | |
if (!this.hasUpdated) { | |
this.hasUpdated = true; | |
this.firstUpdated(changedProperties); | |
} | |
this.updated(changedProperties); | |
} | |
__markUpdated() { | |
this._$changedProperties = new Map(); | |
this.isUpdatePending = false; | |
} | |
/** | |
* Returns a Promise that resolves when the element has completed updating. | |
* The Promise value is a boolean that is `true` if the element completed the | |
* update without triggering another update. The Promise result is `false` if | |
* a property was set inside `updated()`. If the Promise is rejected, an | |
* exception was thrown during the update. | |
* | |
* To await additional asynchronous work, override the `getUpdateComplete` | |
* method. For example, it is sometimes useful to await a rendered element | |
* before fulfilling this Promise. To do this, first await | |
* `super.getUpdateComplete()`, then any subsequent state. | |
* | |
* @return A promise of a boolean that resolves to true if the update completed | |
* without triggering another update. | |
* @category updates | |
*/ | |
get updateComplete() { | |
return this.getUpdateComplete(); | |
} | |
/** | |
* Override point for the `updateComplete` promise. | |
* | |
* It is not safe to override the `updateComplete` getter directly due to a | |
* limitation in TypeScript which means it is not possible to call a | |
* superclass getter (e.g. `super.updateComplete.then(...)`) when the target | |
* language is ES5 (https://github.com/microsoft/TypeScript/issues/338). | |
* This method should be overridden instead. For example: | |
* | |
* ```ts | |
* class MyElement extends LitElement { | |
* override async getUpdateComplete() { | |
* const result = await super.getUpdateComplete(); | |
* await this._myChild.updateComplete; | |
* return result; | |
* } | |
* } | |
* ``` | |
* | |
* @return A promise of a boolean that resolves to true if the update completed | |
* without triggering another update. | |
* @category updates | |
*/ | |
getUpdateComplete() { | |
return this.__updatePromise; | |
} | |
/** | |
* Controls whether or not `update()` should be called when the element requests | |
* an update. By default, this method always returns `true`, but this can be | |
* customized to control when to update. | |
* | |
* @param _changedProperties Map of changed properties with old values | |
* @category updates | |
*/ | |
shouldUpdate(_changedProperties) { | |
return true; | |
} | |
/** | |
* Updates the element. This method reflects property values to attributes. | |
* It can be overridden to render and keep updated element DOM. | |
* Setting properties inside this method will *not* trigger | |
* another update. | |
* | |
* @param _changedProperties Map of changed properties with old values | |
* @category updates | |
*/ | |
update(_changedProperties) { | |
// The forEach() expression will only run when when __reflectingProperties is | |
// defined, and it returns undefined, setting __reflectingProperties to | |
// undefined | |
this.__reflectingProperties &&= this.__reflectingProperties.forEach((p) => this.__propertyToAttribute(p, this[p])); | |
this.__markUpdated(); | |
} | |
/** | |
* Invoked whenever the element is updated. Implement to perform | |
* post-updating tasks via DOM APIs, for example, focusing an element. | |
* | |
* Setting properties inside this method will trigger the element to update | |
* again after this update cycle completes. | |
* | |
* @param _changedProperties Map of changed properties with old values | |
* @category updates | |
*/ | |
updated(_changedProperties) { } | |
/** | |
* Invoked when the element is first updated. Implement to perform one time | |
* work on the element after update. | |
* | |
* ```ts | |
* firstUpdated() { | |
* this.renderRoot.getElementById('my-text-area').focus(); | |
* } | |
* ``` | |
* | |
* Setting properties inside this method will trigger the element to update | |
* again after this update cycle completes. | |
* | |
* @param _changedProperties Map of changed properties with old values | |
* @category updates | |
*/ | |
firstUpdated(_changedProperties) { } | |
} | |
/** | |
* Memoized list of all element styles. | |
* Created lazily on user subclasses when finalizing the class. | |
* @nocollapse | |
* @category styles | |
*/ | |
ReactiveElement.elementStyles = []; | |
/** | |
* Options used when calling `attachShadow`. Set this property to customize | |
* the options for the shadowRoot; for example, to create a closed | |
* shadowRoot: `{mode: 'closed'}`. | |
* | |
* Note, these options are used in `createRenderRoot`. If this method | |
* is customized, options should be respected if possible. | |
* @nocollapse | |
* @category rendering | |
*/ | |
ReactiveElement.shadowRootOptions = { mode: 'open' }; | |
// Assigned here to work around a jscompiler bug with static fields | |
// when compiling to ES5. | |
// https://github.com/google/closure-compiler/issues/3177 | |
ReactiveElement[JSCompiler_renameProperty$1('elementProperties')] = new Map(); | |
ReactiveElement[JSCompiler_renameProperty$1('finalized')] = new Map(); | |
// Apply polyfills if available | |
polyfillSupport$2?.({ ReactiveElement }); | |
// IMPORTANT: do not change the property name or the assignment expression. | |
// This line will be used in regexes to search for ReactiveElement usage. | |
(global$1.reactiveElementVersions ??= []).push('2.0.4'); | |
/** | |
* @license | |
* Copyright 2017 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
// Allows minifiers to rename references to globalThis | |
const global = globalThis; | |
const wrap$1 = (node) => node; | |
const trustedTypes = global.trustedTypes; | |
/** | |
* Our TrustedTypePolicy for HTML which is declared using the html template | |
* tag function. | |
* | |
* That HTML is a developer-authored constant, and is parsed with innerHTML | |
* before any untrusted expressions have been mixed in. Therefor it is | |
* considered safe by construction. | |
*/ | |
const policy = trustedTypes | |
? trustedTypes.createPolicy('lit-html', { | |
createHTML: (s) => s, | |
}) | |
: undefined; | |
// Added to an attribute name to mark the attribute as bound so we can find | |
// it easily. | |
const boundAttributeSuffix = '$lit$'; | |
// This marker is used in many syntactic positions in HTML, so it must be | |
// a valid element name and attribute name. We don't support dynamic names (yet) | |
// but this at least ensures that the parse tree is closer to the template | |
// intention. | |
const marker = `lit$${String(Math.random()).slice(9)}$`; | |
// String used to tell if a comment is a marker comment | |
const markerMatch = '?' + marker; | |
// Text used to insert a comment marker node. We use processing instruction | |
// syntax because it's slightly smaller, but parses as a comment node. | |
const nodeMarker = `<${markerMatch}>`; | |
const d = document; | |
// Creates a dynamic marker. We never have to search for these in the DOM. | |
const createMarker$1 = () => d.createComment(''); | |
const isPrimitive$1 = (value) => value === null || (typeof value != 'object' && typeof value != 'function'); | |
const isArray = Array.isArray; | |
const isIterable = (value) => isArray(value) || | |
// eslint-disable-next-line @typescript-eslint/no-explicit-any | |
typeof value?.[Symbol.iterator] === 'function'; | |
const SPACE_CHAR = `[ \t\n\f\r]`; | |
const ATTR_VALUE_CHAR = `[^ \t\n\f\r"'\`<>=]`; | |
const NAME_CHAR = `[^\\s"'>=/]`; | |
// These regexes represent the five parsing states that we care about in the | |
// Template's HTML scanner. They match the *end* of the state they're named | |
// after. | |
// Depending on the match, we transition to a new state. If there's no match, | |
// we stay in the same state. | |
// Note that the regexes are stateful. We utilize lastIndex and sync it | |
// across the multiple regexes used. In addition to the five regexes below | |
// we also dynamically create a regex to find the matching end tags for raw | |
// text elements. | |
/** | |
* End of text is: `<` followed by: | |
* (comment start) or (tag) or (dynamic tag binding) | |
*/ | |
const textEndRegex = /<(?:(!--|\/[^a-zA-Z])|(\/?[a-zA-Z][^>\s]*)|(\/?$))/g; | |
const COMMENT_START = 1; | |
const TAG_NAME = 2; | |
const DYNAMIC_TAG_NAME = 3; | |
const commentEndRegex = /-->/g; | |
/** | |
* Comments not started with <!--, like </{, can be ended by a single `>` | |
*/ | |
const comment2EndRegex = />/g; | |
/** | |
* The tagEnd regex matches the end of the "inside an opening" tag syntax | |
* position. It either matches a `>`, an attribute-like sequence, or the end | |
* of the string after a space (attribute-name position ending). | |
* | |
* See attributes in the HTML spec: | |
* https://www.w3.org/TR/html5/syntax.html#elements-attributes | |
* | |
* " \t\n\f\r" are HTML space characters: | |
* https://infra.spec.whatwg.org/#ascii-whitespace | |
* | |
* So an attribute is: | |
* * The name: any character except a whitespace character, ("), ('), ">", | |
* "=", or "/". Note: this is different from the HTML spec which also excludes control characters. | |
* * Followed by zero or more space characters | |
* * Followed by "=" | |
* * Followed by zero or more space characters | |
* * Followed by: | |
* * Any character except space, ('), ("), "<", ">", "=", (`), or | |
* * (") then any non-("), or | |
* * (') then any non-(') | |
*/ | |
const tagEndRegex = new RegExp(`>|${SPACE_CHAR}(?:(${NAME_CHAR}+)(${SPACE_CHAR}*=${SPACE_CHAR}*(?:${ATTR_VALUE_CHAR}|("|')|))|$)`, 'g'); | |
const ENTIRE_MATCH = 0; | |
const ATTRIBUTE_NAME = 1; | |
const SPACES_AND_EQUALS = 2; | |
const QUOTE_CHAR = 3; | |
const singleQuoteAttrEndRegex = /'/g; | |
const doubleQuoteAttrEndRegex = /"/g; | |
/** | |
* Matches the raw text elements. | |
* | |
* Comments are not parsed within raw text elements, so we need to search their | |
* text content for marker strings. | |
*/ | |
const rawTextElement = /^(?:script|style|textarea|title)$/i; | |
/** TemplateResult types */ | |
const HTML_RESULT$1 = 1; | |
const SVG_RESULT$1 = 2; | |
// TemplatePart types | |
// IMPORTANT: these must match the values in PartType | |
const ATTRIBUTE_PART = 1; | |
const CHILD_PART = 2; | |
const PROPERTY_PART = 3; | |
const BOOLEAN_ATTRIBUTE_PART = 4; | |
const EVENT_PART = 5; | |
const ELEMENT_PART = 6; | |
const COMMENT_PART = 7; | |
/** | |
* Generates a template literal tag function that returns a TemplateResult with | |
* the given result type. | |
*/ | |
const tag = (type) => (strings, ...values) => { | |
return { | |
// This property needs to remain unminified. | |
['_$litType$']: type, | |
strings, | |
values, | |
}; | |
}; | |
/** | |
* Interprets a template literal as an HTML template that can efficiently | |
* render to and update a container. | |
* | |
* ```ts | |
* const header = (title: string) => html`<h1>${title}</h1>`; | |
* ``` | |
* | |
* The `html` tag returns a description of the DOM to render as a value. It is | |
* lazy, meaning no work is done until the template is rendered. When rendering, | |
* if a template comes from the same expression as a previously rendered result, | |
* it's efficiently updated instead of replaced. | |
*/ | |
const html$1 = tag(HTML_RESULT$1); | |
/** | |
* Interprets a template literal as an SVG fragment that can efficiently | |
* render to and update a container. | |
* | |
* ```ts | |
* const rect = svg`<rect width="10" height="10"></rect>`; | |
* | |
* const myImage = html` | |
* <svg viewBox="0 0 10 10" xmlns="http://www.w3.org/2000/svg"> | |
* ${rect} | |
* </svg>`; | |
* ``` | |
* | |
* The `svg` *tag function* should only be used for SVG fragments, or elements | |
* that would be contained **inside** an `<svg>` HTML element. A common error is | |
* placing an `<svg>` *element* in a template tagged with the `svg` tag | |
* function. The `<svg>` element is an HTML element and should be used within a | |
* template tagged with the {@linkcode html} tag function. | |
* | |
* In LitElement usage, it's invalid to return an SVG fragment from the | |
* `render()` method, as the SVG fragment will be contained within the element's | |
* shadow root and thus cannot be used within an `<svg>` HTML element. | |
*/ | |
const svg$1 = tag(SVG_RESULT$1); | |
/** | |
* A sentinel value that signals that a value was handled by a directive and | |
* should not be written to the DOM. | |
*/ | |
const noChange = Symbol.for('lit-noChange'); | |
/** | |
* A sentinel value that signals a ChildPart to fully clear its content. | |
* | |
* ```ts | |
* const button = html`${ | |
* user.isAdmin | |
* ? html`<button>DELETE</button>` | |
* : nothing | |
* }`; | |
* ``` | |
* | |
* Prefer using `nothing` over other falsy values as it provides a consistent | |
* behavior between various expression binding contexts. | |
* | |
* In child expressions, `undefined`, `null`, `''`, and `nothing` all behave the | |
* same and render no nodes. In attribute expressions, `nothing` _removes_ the | |
* attribute, while `undefined` and `null` will render an empty string. In | |
* property expressions `nothing` becomes `undefined`. | |
*/ | |
const nothing = Symbol.for('lit-nothing'); | |
/** | |
* The cache of prepared templates, keyed by the tagged TemplateStringsArray | |
* and _not_ accounting for the specific template tag used. This means that | |
* template tags cannot be dynamic - the must statically be one of html, svg, | |
* or attr. This restriction simplifies the cache lookup, which is on the hot | |
* path for rendering. | |
*/ | |
const templateCache = new WeakMap(); | |
const walker = d.createTreeWalker(d, 129 /* NodeFilter.SHOW_{ELEMENT|COMMENT} */); | |
function trustFromTemplateString(tsa, stringFromTSA) { | |
// A security check to prevent spoofing of Lit template results. | |
// In the future, we may be able to replace this with Array.isTemplateObject, | |
// though we might need to make that check inside of the html and svg | |
// functions, because precompiled templates don't come in as | |
// TemplateStringArray objects. | |
if (!Array.isArray(tsa) || !tsa.hasOwnProperty('raw')) { | |
let message = 'invalid template strings array'; | |
throw new Error(message); | |
} | |
return policy !== undefined | |
? policy.createHTML(stringFromTSA) | |
: stringFromTSA; | |
} | |
/** | |
* Returns an HTML string for the given TemplateStringsArray and result type | |
* (HTML or SVG), along with the case-sensitive bound attribute names in | |
* template order. The HTML contains comment markers denoting the `ChildPart`s | |
* and suffixes on bound attributes denoting the `AttributeParts`. | |
* | |
* @param strings template strings array | |
* @param type HTML or SVG | |
* @return Array containing `[html, attrNames]` (array returned for terseness, | |
* to avoid object fields since this code is shared with non-minified SSR | |
* code) | |
*/ | |
const getTemplateHtml = (strings, type) => { | |
// Insert makers into the template HTML to represent the position of | |
// bindings. The following code scans the template strings to determine the | |
// syntactic position of the bindings. They can be in text position, where | |
// we insert an HTML comment, attribute value position, where we insert a | |
// sentinel string and re-write the attribute name, or inside a tag where | |
// we insert the sentinel string. | |
const l = strings.length - 1; | |
// Stores the case-sensitive bound attribute names in the order of their | |
// parts. ElementParts are also reflected in this array as undefined | |
// rather than a string, to disambiguate from attribute bindings. | |
const attrNames = []; | |
let html = type === SVG_RESULT$1 ? '<svg>' : ''; | |
// When we're inside a raw text tag (not it's text content), the regex | |
// will still be tagRegex so we can find attributes, but will switch to | |
// this regex when the tag ends. | |
let rawTextEndRegex; | |
// The current parsing state, represented as a reference to one of the | |
// regexes | |
let regex = textEndRegex; | |
for (let i = 0; i < l; i++) { | |
const s = strings[i]; | |
// The index of the end of the last attribute name. When this is | |
// positive at end of a string, it means we're in an attribute value | |
// position and need to rewrite the attribute name. | |
// We also use a special value of -2 to indicate that we encountered | |
// the end of a string in attribute name position. | |
let attrNameEndIndex = -1; | |
let attrName; | |
let lastIndex = 0; | |
let match; | |
// The conditions in this loop handle the current parse state, and the | |
// assignments to the `regex` variable are the state transitions. | |
while (lastIndex < s.length) { | |
// Make sure we start searching from where we previously left off | |
regex.lastIndex = lastIndex; | |
match = regex.exec(s); | |
if (match === null) { | |
break; | |
} | |
lastIndex = regex.lastIndex; | |
if (regex === textEndRegex) { | |
if (match[COMMENT_START] === '!--') { | |
regex = commentEndRegex; | |
} | |
else if (match[COMMENT_START] !== undefined) { | |
// We started a weird comment, like </{ | |
regex = comment2EndRegex; | |
} | |
else if (match[TAG_NAME] !== undefined) { | |
if (rawTextElement.test(match[TAG_NAME])) { | |
// Record if we encounter a raw-text element. We'll switch to | |
// this regex at the end of the tag. | |
rawTextEndRegex = new RegExp(`</${match[TAG_NAME]}`, 'g'); | |
} | |
regex = tagEndRegex; | |
} | |
else if (match[DYNAMIC_TAG_NAME] !== undefined) { | |
regex = tagEndRegex; | |
} | |
} | |
else if (regex === tagEndRegex) { | |
if (match[ENTIRE_MATCH] === '>') { | |
// End of a tag. If we had started a raw-text element, use that | |
// regex | |
regex = rawTextEndRegex ?? textEndRegex; | |
// We may be ending an unquoted attribute value, so make sure we | |
// clear any pending attrNameEndIndex | |
attrNameEndIndex = -1; | |
} | |
else if (match[ATTRIBUTE_NAME] === undefined) { | |
// Attribute name position | |
attrNameEndIndex = -2; | |
} | |
else { | |
attrNameEndIndex = regex.lastIndex - match[SPACES_AND_EQUALS].length; | |
attrName = match[ATTRIBUTE_NAME]; | |
regex = | |
match[QUOTE_CHAR] === undefined | |
? tagEndRegex | |
: match[QUOTE_CHAR] === '"' | |
? doubleQuoteAttrEndRegex | |
: singleQuoteAttrEndRegex; | |
} | |
} | |
else if (regex === doubleQuoteAttrEndRegex || | |
regex === singleQuoteAttrEndRegex) { | |
regex = tagEndRegex; | |
} | |
else if (regex === commentEndRegex || regex === comment2EndRegex) { | |
regex = textEndRegex; | |
} | |
else { | |
// Not one of the five state regexes, so it must be the dynamically | |
// created raw text regex and we're at the close of that element. | |
regex = tagEndRegex; | |
rawTextEndRegex = undefined; | |
} | |
} | |
// We have four cases: | |
// 1. We're in text position, and not in a raw text element | |
// (regex === textEndRegex): insert a comment marker. | |
// 2. We have a non-negative attrNameEndIndex which means we need to | |
// rewrite the attribute name to add a bound attribute suffix. | |
// 3. We're at the non-first binding in a multi-binding attribute, use a | |
// plain marker. | |
// 4. We're somewhere else inside the tag. If we're in attribute name | |
// position (attrNameEndIndex === -2), add a sequential suffix to | |
// generate a unique attribute name. | |
// Detect a binding next to self-closing tag end and insert a space to | |
// separate the marker from the tag end: | |
const end = regex === tagEndRegex && strings[i + 1].startsWith('/>') ? ' ' : ''; | |
html += | |
regex === textEndRegex | |
? s + nodeMarker | |
: attrNameEndIndex >= 0 | |
? (attrNames.push(attrName), | |
s.slice(0, attrNameEndIndex) + | |
boundAttributeSuffix + | |
s.slice(attrNameEndIndex)) + | |
marker + | |
end | |
: s + marker + (attrNameEndIndex === -2 ? i : end); | |
} | |
const htmlResult = html + (strings[l] || '<?>') + (type === SVG_RESULT$1 ? '</svg>' : ''); | |
// Returned as an array for terseness | |
return [trustFromTemplateString(strings, htmlResult), attrNames]; | |
}; | |
class Template { | |
constructor( | |
// This property needs to remain unminified. | |
{ strings, ['_$litType$']: type }, options) { | |
this.parts = []; | |
let node; | |
let nodeIndex = 0; | |
let attrNameIndex = 0; | |
const partCount = strings.length - 1; | |
const parts = this.parts; | |
// Create template element | |
const [html, attrNames] = getTemplateHtml(strings, type); | |
this.el = Template.createElement(html, options); | |
walker.currentNode = this.el.content; | |
// Re-parent SVG nodes into template root | |
if (type === SVG_RESULT$1) { | |
const svgElement = this.el.content.firstChild; | |
svgElement.replaceWith(...svgElement.childNodes); | |
} | |
// Walk the template to find binding markers and create TemplateParts | |
while ((node = walker.nextNode()) !== null && parts.length < partCount) { | |
if (node.nodeType === 1) { | |
// TODO (justinfagnani): for attempted dynamic tag names, we don't | |
// increment the bindingIndex, and it'll be off by 1 in the element | |
// and off by two after it. | |
if (node.hasAttributes()) { | |
for (const name of node.getAttributeNames()) { | |
if (name.endsWith(boundAttributeSuffix)) { | |
const realName = attrNames[attrNameIndex++]; | |
const value = node.getAttribute(name); | |
const statics = value.split(marker); | |
const m = /([.?@])?(.*)/.exec(realName); | |
parts.push({ | |
type: ATTRIBUTE_PART, | |
index: nodeIndex, | |
name: m[2], | |
strings: statics, | |
ctor: m[1] === '.' | |
? PropertyPart | |
: m[1] === '?' | |
? BooleanAttributePart | |
: m[1] === '@' | |
? EventPart | |
: AttributePart, | |
}); | |
node.removeAttribute(name); | |
} | |
else if (name.startsWith(marker)) { | |
parts.push({ | |
type: ELEMENT_PART, | |
index: nodeIndex, | |
}); | |
node.removeAttribute(name); | |
} | |
} | |
} | |
// TODO (justinfagnani): benchmark the regex against testing for each | |
// of the 3 raw text element names. | |
if (rawTextElement.test(node.tagName)) { | |
// For raw text elements we need to split the text content on | |
// markers, create a Text node for each segment, and create | |
// a TemplatePart for each marker. | |
const strings = node.textContent.split(marker); | |
const lastIndex = strings.length - 1; | |
if (lastIndex > 0) { | |
node.textContent = trustedTypes | |
? trustedTypes.emptyScript | |
: ''; | |
// Generate a new text node for each literal section | |
// These nodes are also used as the markers for node parts | |
// We can't use empty text nodes as markers because they're | |
// normalized when cloning in IE (could simplify when | |
// IE is no longer supported) | |
for (let i = 0; i < lastIndex; i++) { | |
node.append(strings[i], createMarker$1()); | |
// Walk past the marker node we just added | |
walker.nextNode(); | |
parts.push({ type: CHILD_PART, index: ++nodeIndex }); | |
} | |
// Note because this marker is added after the walker's current | |
// node, it will be walked to in the outer loop (and ignored), so | |
// we don't need to adjust nodeIndex here | |
node.append(strings[lastIndex], createMarker$1()); | |
} | |
} | |
} | |
else if (node.nodeType === 8) { | |
const data = node.data; | |
if (data === markerMatch) { | |
parts.push({ type: CHILD_PART, index: nodeIndex }); | |
} | |
else { | |
let i = -1; | |
while ((i = node.data.indexOf(marker, i + 1)) !== -1) { | |
// Comment node has a binding marker inside, make an inactive part | |
// The binding won't work, but subsequent bindings will | |
parts.push({ type: COMMENT_PART, index: nodeIndex }); | |
// Move to the end of the match | |
i += marker.length - 1; | |
} | |
} | |
} | |
nodeIndex++; | |
} | |
} | |
// Overridden via `litHtmlPolyfillSupport` to provide platform support. | |
/** @nocollapse */ | |
static createElement(html, _options) { | |
const el = d.createElement('template'); | |
el.innerHTML = html; | |
return el; | |
} | |
} | |
function resolveDirective(part, value, parent = part, attributeIndex) { | |
// Bail early if the value is explicitly noChange. Note, this means any | |
// nested directive is still attached and is not run. | |
if (value === noChange) { | |
return value; | |
} | |
let currentDirective = attributeIndex !== undefined | |
? parent.__directives?.[attributeIndex] | |
: parent.__directive; | |
const nextDirectiveConstructor = isPrimitive$1(value) | |
? undefined | |
: // This property needs to remain unminified. | |
value['_$litDirective$']; | |
if (currentDirective?.constructor !== nextDirectiveConstructor) { | |
// This property needs to remain unminified. | |
currentDirective?.['_$notifyDirectiveConnectionChanged']?.(false); | |
if (nextDirectiveConstructor === undefined) { | |
currentDirective = undefined; | |
} | |
else { | |
currentDirective = new nextDirectiveConstructor(part); | |
currentDirective._$initialize(part, parent, attributeIndex); | |
} | |
if (attributeIndex !== undefined) { | |
(parent.__directives ??= [])[attributeIndex] = | |
currentDirective; | |
} | |
else { | |
parent.__directive = currentDirective; | |
} | |
} | |
if (currentDirective !== undefined) { | |
value = resolveDirective(part, currentDirective._$resolve(part, value.values), currentDirective, attributeIndex); | |
} | |
return value; | |
} | |
/** | |
* An updateable instance of a Template. Holds references to the Parts used to | |
* update the template instance. | |
*/ | |
class TemplateInstance { | |
constructor(template, parent) { | |
this._$parts = []; | |
/** @internal */ | |
this._$disconnectableChildren = undefined; | |
this._$template = template; | |
this._$parent = parent; | |
} | |
// Called by ChildPart parentNode getter | |
get parentNode() { | |
return this._$parent.parentNode; | |
} | |
// See comment in Disconnectable interface for why this is a getter | |
get _$isConnected() { | |
return this._$parent._$isConnected; | |
} | |
// This method is separate from the constructor because we need to return a | |
// DocumentFragment and we don't want to hold onto it with an instance field. | |
_clone(options) { | |
const { el: { content }, parts: parts, } = this._$template; | |
const fragment = (options?.creationScope ?? d).importNode(content, true); | |
walker.currentNode = fragment; | |
let node = walker.nextNode(); | |
let nodeIndex = 0; | |
let partIndex = 0; | |
let templatePart = parts[0]; | |
while (templatePart !== undefined) { | |
if (nodeIndex === templatePart.index) { | |
let part; | |
if (templatePart.type === CHILD_PART) { | |
part = new ChildPart$1(node, node.nextSibling, this, options); | |
} | |
else if (templatePart.type === ATTRIBUTE_PART) { | |
part = new templatePart.ctor(node, templatePart.name, templatePart.strings, this, options); | |
} | |
else if (templatePart.type === ELEMENT_PART) { | |
part = new ElementPart(node, this, options); | |
} | |
this._$parts.push(part); | |
templatePart = parts[++partIndex]; | |
} | |
if (nodeIndex !== templatePart?.index) { | |
node = walker.nextNode(); | |
nodeIndex++; | |
} | |
} | |
// We need to set the currentNode away from the cloned tree so that we | |
// don't hold onto the tree even if the tree is detached and should be | |
// freed. | |
walker.currentNode = d; | |
return fragment; | |
} | |
_update(values) { | |
let i = 0; | |
for (const part of this._$parts) { | |
if (part !== undefined) { | |
if (part.strings !== undefined) { | |
part._$setValue(values, part, i); | |
// The number of values the part consumes is part.strings.length - 1 | |
// since values are in between template spans. We increment i by 1 | |
// later in the loop, so increment it by part.strings.length - 2 here | |
i += part.strings.length - 2; | |
} | |
else { | |
part._$setValue(values[i]); | |
} | |
} | |
i++; | |
} | |
} | |
} | |
class ChildPart$1 { | |
// See comment in Disconnectable interface for why this is a getter | |
get _$isConnected() { | |
// ChildParts that are not at the root should always be created with a | |
// parent; only RootChildNode's won't, so they return the local isConnected | |
// state | |
return this._$parent?._$isConnected ?? this.__isConnected; | |
} | |
constructor(startNode, endNode, parent, options) { | |
this.type = CHILD_PART; | |
this._$committedValue = nothing; | |
// The following fields will be patched onto ChildParts when required by | |
// AsyncDirective | |
/** @internal */ | |
this._$disconnectableChildren = undefined; | |
this._$startNode = startNode; | |
this._$endNode = endNode; | |
this._$parent = parent; | |
this.options = options; | |
// Note __isConnected is only ever accessed on RootParts (i.e. when there is | |
// no _$parent); the value on a non-root-part is "don't care", but checking | |
// for parent would be more code | |
this.__isConnected = options?.isConnected ?? true; | |
} | |
/** | |
* The parent node into which the part renders its content. | |
* | |
* A ChildPart's content consists of a range of adjacent child nodes of | |
* `.parentNode`, possibly bordered by 'marker nodes' (`.startNode` and | |
* `.endNode`). | |
* | |
* - If both `.startNode` and `.endNode` are non-null, then the part's content | |
* consists of all siblings between `.startNode` and `.endNode`, exclusively. | |
* | |
* - If `.startNode` is non-null but `.endNode` is null, then the part's | |
* content consists of all siblings following `.startNode`, up to and | |
* including the last child of `.parentNode`. If `.endNode` is non-null, then | |
* `.startNode` will always be non-null. | |
* | |
* - If both `.endNode` and `.startNode` are null, then the part's content | |
* consists of all child nodes of `.parentNode`. | |
*/ | |
get parentNode() { | |
let parentNode = wrap$1(this._$startNode).parentNode; | |
const parent = this._$parent; | |
if (parent !== undefined && | |
parentNode?.nodeType === 11 /* Node.DOCUMENT_FRAGMENT */) { | |
// If the parentNode is a DocumentFragment, it may be because the DOM is | |
// still in the cloned fragment during initial render; if so, get the real | |
// parentNode the part will be committed into by asking the parent. | |
parentNode = parent.parentNode; | |
} | |
return parentNode; | |
} | |
/** | |
* The part's leading marker node, if any. See `.parentNode` for more | |
* information. | |
*/ | |
get startNode() { | |
return this._$startNode; | |
} | |
/** | |
* The part's trailing marker node, if any. See `.parentNode` for more | |
* information. | |
*/ | |
get endNode() { | |
return this._$endNode; | |
} | |
_$setValue(value, directiveParent = this) { | |
value = resolveDirective(this, value, directiveParent); | |
if (isPrimitive$1(value)) { | |
// Non-rendering child values. It's important that these do not render | |
// empty text nodes to avoid issues with preventing default <slot> | |
// fallback content. | |
if (value === nothing || value == null || value === '') { | |
if (this._$committedValue !== nothing) { | |
this._$clear(); | |
} | |
this._$committedValue = nothing; | |
} | |
else if (value !== this._$committedValue && value !== noChange) { | |
this._commitText(value); | |
} | |
// This property needs to remain unminified. | |
} | |
else if (value['_$litType$'] !== undefined) { | |
this._commitTemplateResult(value); | |
} | |
else if (value.nodeType !== undefined) { | |
this._commitNode(value); | |
} | |
else if (isIterable(value)) { | |
this._commitIterable(value); | |
} | |
else { | |
// Fallback, will render the string representation | |
this._commitText(value); | |
} | |
} | |
_insert(node) { | |
return wrap$1(wrap$1(this._$startNode).parentNode).insertBefore(node, this._$endNode); | |
} | |
_commitNode(value) { | |
if (this._$committedValue !== value) { | |
this._$clear(); | |
this._$committedValue = this._insert(value); | |
} | |
} | |
_commitText(value) { | |
// If the committed value is a primitive it means we called _commitText on | |
// the previous render, and we know that this._$startNode.nextSibling is a | |
// Text node. We can now just replace the text content (.data) of the node. | |
if (this._$committedValue !== nothing && | |
isPrimitive$1(this._$committedValue)) { | |
const node = wrap$1(this._$startNode).nextSibling; | |
node.data = value; | |
} | |
else { | |
{ | |
this._commitNode(d.createTextNode(value)); | |
} | |
} | |
this._$committedValue = value; | |
} | |
_commitTemplateResult(result) { | |
// This property needs to remain unminified. | |
const { values, ['_$litType$']: type } = result; | |
// If $litType$ is a number, result is a plain TemplateResult and we get | |
// the template from the template cache. If not, result is a | |
// CompiledTemplateResult and _$litType$ is a CompiledTemplate and we need | |
// to create the <template> element the first time we see it. | |
const template = typeof type === 'number' | |
? this._$getTemplate(result) | |
: (type.el === undefined && | |
(type.el = Template.createElement(trustFromTemplateString(type.h, type.h[0]), this.options)), | |
type); | |
if (this._$committedValue?._$template === template) { | |
this._$committedValue._update(values); | |
} | |
else { | |
const instance = new TemplateInstance(template, this); | |
const fragment = instance._clone(this.options); | |
instance._update(values); | |
this._commitNode(fragment); | |
this._$committedValue = instance; | |
} | |
} | |
// Overridden via `litHtmlPolyfillSupport` to provide platform support. | |
/** @internal */ | |
_$getTemplate(result) { | |
let template = templateCache.get(result.strings); | |
if (template === undefined) { | |
templateCache.set(result.strings, (template = new Template(result))); | |
} | |
return template; | |
} | |
_commitIterable(value) { | |
// For an Iterable, we create a new InstancePart per item, then set its | |
// value to the item. This is a little bit of overhead for every item in | |
// an Iterable, but it lets us recurse easily and efficiently update Arrays | |
// of TemplateResults that will be commonly returned from expressions like: | |
// array.map((i) => html`${i}`), by reusing existing TemplateInstances. | |
// If value is an array, then the previous render was of an | |
// iterable and value will contain the ChildParts from the previous | |
// render. If value is not an array, clear this part and make a new | |
// array for ChildParts. | |
if (!isArray(this._$committedValue)) { | |
this._$committedValue = []; | |
this._$clear(); | |
} | |
// Lets us keep track of how many items we stamped so we can clear leftover | |
// items from a previous render | |
const itemParts = this._$committedValue; | |
let partIndex = 0; | |
let itemPart; | |
for (const item of value) { | |
if (partIndex === itemParts.length) { | |
// If no existing part, create a new one | |
// TODO (justinfagnani): test perf impact of always creating two parts | |
// instead of sharing parts between nodes | |
// https://github.com/lit/lit/issues/1266 | |
itemParts.push((itemPart = new ChildPart$1(this._insert(createMarker$1()), this._insert(createMarker$1()), this, this.options))); | |
} | |
else { | |
// Reuse an existing part | |
itemPart = itemParts[partIndex]; | |
} | |
itemPart._$setValue(item); | |
partIndex++; | |
} | |
if (partIndex < itemParts.length) { | |
// itemParts always have end nodes | |
this._$clear(itemPart && wrap$1(itemPart._$endNode).nextSibling, partIndex); | |
// Truncate the parts array so _value reflects the current state | |
itemParts.length = partIndex; | |
} | |
} | |
/** | |
* Removes the nodes contained within this Part from the DOM. | |
* | |
* @param start Start node to clear from, for clearing a subset of the part's | |
* DOM (used when truncating iterables) | |
* @param from When `start` is specified, the index within the iterable from | |
* which ChildParts are being removed, used for disconnecting directives in | |
* those Parts. | |
* | |
* @internal | |
*/ | |
_$clear(start = wrap$1(this._$startNode).nextSibling, from) { | |
this._$notifyConnectionChanged?.(false, true, from); | |
while (start && start !== this._$endNode) { | |
const n = wrap$1(start).nextSibling; | |
wrap$1(start).remove(); | |
start = n; | |
} | |
} | |
/** | |
* Implementation of RootPart's `isConnected`. Note that this metod | |
* should only be called on `RootPart`s (the `ChildPart` returned from a | |
* top-level `render()` call). It has no effect on non-root ChildParts. | |
* @param isConnected Whether to set | |
* @internal | |
*/ | |
setConnected(isConnected) { | |
if (this._$parent === undefined) { | |
this.__isConnected = isConnected; | |
this._$notifyConnectionChanged?.(isConnected); | |
} | |
} | |
} | |
class AttributePart { | |
get tagName() { | |
return this.element.tagName; | |
} | |
// See comment in Disconnectable interface for why this is a getter | |
get _$isConnected() { | |
return this._$parent._$isConnected; | |
} | |
constructor(element, name, strings, parent, options) { | |
this.type = ATTRIBUTE_PART; | |
/** @internal */ | |
this._$committedValue = nothing; | |
/** @internal */ | |
this._$disconnectableChildren = undefined; | |
this.element = element; | |
this.name = name; | |
this._$parent = parent; | |
this.options = options; | |
if (strings.length > 2 || strings[0] !== '' || strings[1] !== '') { | |
this._$committedValue = new Array(strings.length - 1).fill(new String()); | |
this.strings = strings; | |
} | |
else { | |
this._$committedValue = nothing; | |
} | |
} | |
/** | |
* Sets the value of this part by resolving the value from possibly multiple | |
* values and static strings and committing it to the DOM. | |
* If this part is single-valued, `this._strings` will be undefined, and the | |
* method will be called with a single value argument. If this part is | |
* multi-value, `this._strings` will be defined, and the method is called | |
* with the value array of the part's owning TemplateInstance, and an offset | |
* into the value array from which the values should be read. | |
* This method is overloaded this way to eliminate short-lived array slices | |
* of the template instance values, and allow a fast-path for single-valued | |
* parts. | |
* | |
* @param value The part value, or an array of values for multi-valued parts | |
* @param valueIndex the index to start reading values from. `undefined` for | |
* single-valued parts | |
* @param noCommit causes the part to not commit its value to the DOM. Used | |
* in hydration to prime attribute parts with their first-rendered value, | |
* but not set the attribute, and in SSR to no-op the DOM operation and | |
* capture the value for serialization. | |
* | |
* @internal | |
*/ | |
_$setValue(value, directiveParent = this, valueIndex, noCommit) { | |
const strings = this.strings; | |
// Whether any of the values has changed, for dirty-checking | |
let change = false; | |
if (strings === undefined) { | |
// Single-value binding case | |
value = resolveDirective(this, value, directiveParent, 0); | |
change = | |
!isPrimitive$1(value) || | |
(value !== this._$committedValue && value !== noChange); | |
if (change) { | |
this._$committedValue = value; | |
} | |
} | |
else { | |
// Interpolation case | |
const values = value; | |
value = strings[0]; | |
let i, v; | |
for (i = 0; i < strings.length - 1; i++) { | |
v = resolveDirective(this, values[valueIndex + i], directiveParent, i); | |
if (v === noChange) { | |
// If the user-provided value is `noChange`, use the previous value | |
v = this._$committedValue[i]; | |
} | |
change ||= | |
!isPrimitive$1(v) || v !== this._$committedValue[i]; | |
if (v === nothing) { | |
value = nothing; | |
} | |
else if (value !== nothing) { | |
value += (v ?? '') + strings[i + 1]; | |
} | |
// We always record each value, even if one is `nothing`, for future | |
// change detection. | |
this._$committedValue[i] = v; | |
} | |
} | |
if (change && !noCommit) { | |
this._commitValue(value); | |
} | |
} | |
/** @internal */ | |
_commitValue(value) { | |
if (value === nothing) { | |
wrap$1(this.element).removeAttribute(this.name); | |
} | |
else { | |
wrap$1(this.element).setAttribute(this.name, (value ?? '')); | |
} | |
} | |
} | |
class PropertyPart extends AttributePart { | |
constructor() { | |
super(...arguments); | |
this.type = PROPERTY_PART; | |
} | |
/** @internal */ | |
_commitValue(value) { | |
// eslint-disable-next-line @typescript-eslint/no-explicit-any | |
this.element[this.name] = value === nothing ? undefined : value; | |
} | |
} | |
class BooleanAttributePart extends AttributePart { | |
constructor() { | |
super(...arguments); | |
this.type = BOOLEAN_ATTRIBUTE_PART; | |
} | |
/** @internal */ | |
_commitValue(value) { | |
wrap$1(this.element).toggleAttribute(this.name, !!value && value !== nothing); | |
} | |
} | |
class EventPart extends AttributePart { | |
constructor(element, name, strings, parent, options) { | |
super(element, name, strings, parent, options); | |
this.type = EVENT_PART; | |
} | |
// EventPart does not use the base _$setValue/_resolveValue implementation | |
// since the dirty checking is more complex | |
/** @internal */ | |
_$setValue(newListener, directiveParent = this) { | |
newListener = | |
resolveDirective(this, newListener, directiveParent, 0) ?? nothing; | |
if (newListener === noChange) { | |
return; | |
} | |
const oldListener = this._$committedValue; | |
// If the new value is nothing or any options change we have to remove the | |
// part as a listener. | |
const shouldRemoveListener = (newListener === nothing && oldListener !== nothing) || | |
newListener.capture !== | |
oldListener.capture || | |
newListener.once !== | |
oldListener.once || | |
newListener.passive !== | |
oldListener.passive; | |
// If the new value is not nothing and we removed the listener, we have | |
// to add the part as a listener. | |
const shouldAddListener = newListener !== nothing && | |
(oldListener === nothing || shouldRemoveListener); | |
if (shouldRemoveListener) { | |
this.element.removeEventListener(this.name, this, oldListener); | |
} | |
if (shouldAddListener) { | |
// Beware: IE11 and Chrome 41 don't like using the listener as the | |
// options object. Figure out how to deal w/ this in IE11 - maybe | |
// patch addEventListener? | |
this.element.addEventListener(this.name, this, newListener); | |
} | |
this._$committedValue = newListener; | |
} | |
handleEvent(event) { | |
if (typeof this._$committedValue === 'function') { | |
this._$committedValue.call(this.options?.host ?? this.element, event); | |
} | |
else { | |
this._$committedValue.handleEvent(event); | |
} | |
} | |
} | |
class ElementPart { | |
constructor(element, parent, options) { | |
this.element = element; | |
this.type = ELEMENT_PART; | |
/** @internal */ | |
this._$disconnectableChildren = undefined; | |
this._$parent = parent; | |
this.options = options; | |
} | |
// See comment in Disconnectable interface for why this is a getter | |
get _$isConnected() { | |
return this._$parent._$isConnected; | |
} | |
_$setValue(value) { | |
resolveDirective(this, value); | |
} | |
} | |
/** | |
* END USERS SHOULD NOT RELY ON THIS OBJECT. | |
* | |
* Private exports for use by other Lit packages, not intended for use by | |
* external users. | |
* | |
* We currently do not make a mangled rollup build of the lit-ssr code. In order | |
* to keep a number of (otherwise private) top-level exports mangled in the | |
* client side code, we export a _$LH object containing those members (or | |
* helper methods for accessing private fields of those members), and then | |
* re-export them for use in lit-ssr. This keeps lit-ssr agnostic to whether the | |
* client-side code is being used in `dev` mode or `prod` mode. | |
* | |
* This has a unique name, to disambiguate it from private exports in | |
* lit-element, which re-exports all of lit-html. | |
* | |
* @private | |
*/ | |
const _$LH = { | |
// Used in lit-ssr | |
_boundAttributeSuffix: boundAttributeSuffix, | |
_marker: marker, | |
_markerMatch: markerMatch, | |
_HTML_RESULT: HTML_RESULT$1, | |
_getTemplateHtml: getTemplateHtml, | |
// Used in tests and private-ssr-support | |
_TemplateInstance: TemplateInstance, | |
_isIterable: isIterable, | |
_resolveDirective: resolveDirective, | |
_ChildPart: ChildPart$1, | |
_AttributePart: AttributePart, | |
_BooleanAttributePart: BooleanAttributePart, | |
_EventPart: EventPart, | |
_PropertyPart: PropertyPart, | |
_ElementPart: ElementPart, | |
}; | |
// Apply polyfills if available | |
const polyfillSupport$1 = global.litHtmlPolyfillSupport; | |
polyfillSupport$1?.(Template, ChildPart$1); | |
// IMPORTANT: do not change the property name or the assignment expression. | |
// This line will be used in regexes to search for lit-html usage. | |
(global.litHtmlVersions ??= []).push('3.1.2'); | |
/** | |
* Renders a value, usually a lit-html TemplateResult, to the container. | |
* | |
* This example renders the text "Hello, Zoe!" inside a paragraph tag, appending | |
* it to the container `document.body`. | |
* | |
* ```js | |
* import {html, render} from 'lit'; | |
* | |
* const name = "Zoe"; | |
* render(html`<p>Hello, ${name}!</p>`, document.body); | |
* ``` | |
* | |
* @param value Any [renderable | |
* value](https://lit.dev/docs/templates/expressions/#child-expressions), | |
* typically a {@linkcode TemplateResult} created by evaluating a template tag | |
* like {@linkcode html} or {@linkcode svg}. | |
* @param container A DOM container to render to. The first render will append | |
* the rendered value to the container, and subsequent renders will | |
* efficiently update the rendered value if the same result type was | |
* previously rendered there. | |
* @param options See {@linkcode RenderOptions} for options documentation. | |
* @see | |
* {@link https://lit.dev/docs/libraries/standalone-templates/#rendering-lit-html-templates| Rendering Lit HTML Templates} | |
*/ | |
const render = (value, container, options) => { | |
const partOwnerNode = options?.renderBefore ?? container; | |
// This property needs to remain unminified. | |
// eslint-disable-next-line @typescript-eslint/no-explicit-any | |
let part = partOwnerNode['_$litPart$']; | |
if (part === undefined) { | |
const endNode = options?.renderBefore ?? null; | |
// This property needs to remain unminified. | |
// eslint-disable-next-line @typescript-eslint/no-explicit-any | |
partOwnerNode['_$litPart$'] = part = new ChildPart$1(container.insertBefore(createMarker$1(), endNode), endNode, undefined, options ?? {}); | |
} | |
part._$setValue(value); | |
return part; | |
}; | |
/** | |
* @license | |
* Copyright 2017 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
/* | |
* When using Closure Compiler, JSCompiler_renameProperty(property, object) is | |
* replaced at compile time by the munged name for object[property]. We cannot | |
* alias this function, so we have to use a small shim that has the same | |
* behavior when not compiling. | |
*/ | |
/*@__INLINE__*/ | |
const JSCompiler_renameProperty = (prop, _obj) => prop; | |
/** | |
* Base element class that manages element properties and attributes, and | |
* renders a lit-html template. | |
* | |
* To define a component, subclass `LitElement` and implement a | |
* `render` method to provide the component's template. Define properties | |
* using the {@linkcode LitElement.properties properties} property or the | |
* {@linkcode property} decorator. | |
*/ | |
class LitElement extends ReactiveElement { | |
constructor() { | |
super(...arguments); | |
/** | |
* @category rendering | |
*/ | |
this.renderOptions = { host: this }; | |
this.__childPart = undefined; | |
} | |
/** | |
* @category rendering | |
*/ | |
createRenderRoot() { | |
const renderRoot = super.createRenderRoot(); | |
// When adoptedStyleSheets are shimmed, they are inserted into the | |
// shadowRoot by createRenderRoot. Adjust the renderBefore node so that | |
// any styles in Lit content render before adoptedStyleSheets. This is | |
// important so that adoptedStyleSheets have precedence over styles in | |
// the shadowRoot. | |
this.renderOptions.renderBefore ??= renderRoot.firstChild; | |
return renderRoot; | |
} | |
/** | |
* Updates the element. This method reflects property values to attributes | |
* and calls `render` to render DOM via lit-html. Setting properties inside | |
* this method will *not* trigger another update. | |
* @param changedProperties Map of changed properties with old values | |
* @category updates | |
*/ | |
update(changedProperties) { | |
// Setting properties in `render` should not trigger an update. Since | |
// updates are allowed after super.update, it's important to call `render` | |
// before that. | |
const value = this.render(); | |
if (!this.hasUpdated) { | |
this.renderOptions.isConnected = this.isConnected; | |
} | |
super.update(changedProperties); | |
this.__childPart = render(value, this.renderRoot, this.renderOptions); | |
} | |
/** | |
* Invoked when the component is added to the document's DOM. | |
* | |
* In `connectedCallback()` you should setup tasks that should only occur when | |
* the element is connected to the document. The most common of these is | |
* adding event listeners to nodes external to the element, like a keydown | |
* event handler added to the window. | |
* | |
* ```ts | |
* connectedCallback() { | |
* super.connectedCallback(); | |
* addEventListener('keydown', this._handleKeydown); | |
* } | |
* ``` | |
* | |
* Typically, anything done in `connectedCallback()` should be undone when the | |
* element is disconnected, in `disconnectedCallback()`. | |
* | |
* @category lifecycle | |
*/ | |
connectedCallback() { | |
super.connectedCallback(); | |
this.__childPart?.setConnected(true); | |
} | |
/** | |
* Invoked when the component is removed from the document's DOM. | |
* | |
* This callback is the main signal to the element that it may no longer be | |
* used. `disconnectedCallback()` should ensure that nothing is holding a | |
* reference to the element (such as event listeners added to nodes external | |
* to the element), so that it is free to be garbage collected. | |
* | |
* ```ts | |
* disconnectedCallback() { | |
* super.disconnectedCallback(); | |
* window.removeEventListener('keydown', this._handleKeydown); | |
* } | |
* ``` | |
* | |
* An element may be re-connected after being disconnected. | |
* | |
* @category lifecycle | |
*/ | |
disconnectedCallback() { | |
super.disconnectedCallback(); | |
this.__childPart?.setConnected(false); | |
} | |
/** | |
* Invoked on each update to perform rendering tasks. This method may return | |
* any value renderable by lit-html's `ChildPart` - typically a | |
* `TemplateResult`. Setting properties inside this method will *not* trigger | |
* the element to update. | |
* @category rendering | |
*/ | |
render() { | |
return noChange; | |
} | |
} | |
// This property needs to remain unminified. | |
LitElement['_$litElement$'] = true; | |
/** | |
* Ensure this class is marked as `finalized` as an optimization ensuring | |
* it will not needlessly try to `finalize`. | |
* | |
* Note this property name is a string to prevent breaking Closure JS Compiler | |
* optimizations. See @lit/reactive-element for more information. | |
*/ | |
LitElement[JSCompiler_renameProperty('finalized')] = true; | |
// Install hydration if available | |
globalThis.litElementHydrateSupport?.({ LitElement }); | |
// Apply polyfills if available | |
const polyfillSupport = globalThis.litElementPolyfillSupport; | |
polyfillSupport?.({ LitElement }); | |
/** | |
* END USERS SHOULD NOT RELY ON THIS OBJECT. | |
* | |
* Private exports for use by other Lit packages, not intended for use by | |
* external users. | |
* | |
* We currently do not make a mangled rollup build of the lit-ssr code. In order | |
* to keep a number of (otherwise private) top-level exports mangled in the | |
* client side code, we export a _$LE object containing those members (or | |
* helper methods for accessing private fields of those members), and then | |
* re-export them for use in lit-ssr. This keeps lit-ssr agnostic to whether the | |
* client-side code is being used in `dev` mode or `prod` mode. | |
* | |
* This has a unique name, to disambiguate it from private exports in | |
* lit-html, since this module re-exports all of lit-html. | |
* | |
* @private | |
*/ | |
const _$LE = { | |
_$attributeToProperty: (el, name, value) => { | |
// eslint-disable-next-line | |
el._$attributeToProperty(name, value); | |
}, | |
// eslint-disable-next-line | |
_$changedProperties: (el) => el._$changedProperties, | |
}; | |
// IMPORTANT: do not change the property name or the assignment expression. | |
// This line will be used in regexes to search for LitElement usage. | |
(globalThis.litElementVersions ??= []).push('4.0.4'); | |
/** | |
* @license | |
* Copyright 2022 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
/** | |
* @fileoverview | |
* | |
* This file exports a boolean const whose value will depend on what environment | |
* the module is being imported from. | |
*/ | |
const NODE_MODE = false; | |
/** | |
* A boolean that will be `true` in server environments like Node, and `false` | |
* in browser environments. Note that your server environment or toolchain must | |
* support the `"node"` export condition for this to be `true`. | |
* | |
* This can be used when authoring components to change behavior based on | |
* whether or not the component is executing in an SSR context. | |
*/ | |
const isServer = NODE_MODE; | |
/** | |
* @license | |
* Copyright 2020 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
const { _ChildPart: ChildPart } = _$LH; | |
const wrap = (node) => node; | |
/** | |
* Tests if a value is a primitive value. | |
* | |
* See https://tc39.github.io/ecma262/#sec-typeof-operator | |
*/ | |
const isPrimitive = (value) => value === null || (typeof value != 'object' && typeof value != 'function'); | |
const TemplateResultType = { | |
HTML: 1, | |
SVG: 2, | |
}; | |
/** | |
* Tests if a value is a TemplateResult or a CompiledTemplateResult. | |
*/ | |
const isTemplateResult = (value, type) => type === undefined | |
? // This property needs to remain unminified. | |
value?.['_$litType$'] !== undefined | |
: value?.['_$litType$'] === type; | |
/** | |
* Tests if a value is a CompiledTemplateResult. | |
*/ | |
const isCompiledTemplateResult = (value) => { | |
return value?.['_$litType$']?.h != null; | |
}; | |
/** | |
* Tests if a value is a DirectiveResult. | |
*/ | |
const isDirectiveResult = (value) => | |
// This property needs to remain unminified. | |
value?.['_$litDirective$'] !== undefined; | |
/** | |
* Retrieves the Directive class for a DirectiveResult | |
*/ | |
const getDirectiveClass = (value) => | |
// This property needs to remain unminified. | |
value?.['_$litDirective$']; | |
/** | |
* Tests whether a part has only a single-expression with no strings to | |
* interpolate between. | |
* | |
* Only AttributePart and PropertyPart can have multiple expressions. | |
* Multi-expression parts have a `strings` property and single-expression | |
* parts do not. | |
*/ | |
const isSingleExpression = (part) => part.strings === undefined; | |
const createMarker = () => document.createComment(''); | |
/** | |
* Inserts a ChildPart into the given container ChildPart's DOM, either at the | |
* end of the container ChildPart, or before the optional `refPart`. | |
* | |
* This does not add the part to the containerPart's committed value. That must | |
* be done by callers. | |
* | |
* @param containerPart Part within which to add the new ChildPart | |
* @param refPart Part before which to add the new ChildPart; when omitted the | |
* part added to the end of the `containerPart` | |
* @param part Part to insert, or undefined to create a new part | |
*/ | |
const insertPart = (containerPart, refPart, part) => { | |
const container = wrap(containerPart._$startNode).parentNode; | |
const refNode = refPart === undefined ? containerPart._$endNode : refPart._$startNode; | |
if (part === undefined) { | |
const startNode = wrap(container).insertBefore(createMarker(), refNode); | |
const endNode = wrap(container).insertBefore(createMarker(), refNode); | |
part = new ChildPart(startNode, endNode, containerPart, containerPart.options); | |
} | |
else { | |
const endNode = wrap(part._$endNode).nextSibling; | |
const oldParent = part._$parent; | |
const parentChanged = oldParent !== containerPart; | |
if (parentChanged) { | |
part._$reparentDisconnectables?.(containerPart); | |
// Note that although `_$reparentDisconnectables` updates the part's | |
// `_$parent` reference after unlinking from its current parent, that | |
// method only exists if Disconnectables are present, so we need to | |
// unconditionally set it here | |
part._$parent = containerPart; | |
// Since the _$isConnected getter is somewhat costly, only | |
// read it once we know the subtree has directives that need | |
// to be notified | |
let newConnectionState; | |
if (part._$notifyConnectionChanged !== undefined && | |
(newConnectionState = containerPart._$isConnected) !== | |
oldParent._$isConnected) { | |
part._$notifyConnectionChanged(newConnectionState); | |
} | |
} | |
if (endNode !== refNode || parentChanged) { | |
let start = part._$startNode; | |
while (start !== endNode) { | |
const n = wrap(start).nextSibling; | |
wrap(container).insertBefore(start, refNode); | |
start = n; | |
} | |
} | |
} | |
return part; | |
}; | |
/** | |
* Sets the value of a Part. | |
* | |
* Note that this should only be used to set/update the value of user-created | |
* parts (i.e. those created using `insertPart`); it should not be used | |
* by directives to set the value of the directive's container part. Directives | |
* should return a value from `update`/`render` to update their part state. | |
* | |
* For directives that require setting their part value asynchronously, they | |
* should extend `AsyncDirective` and call `this.setValue()`. | |
* | |
* @param part Part to set | |
* @param value Value to set | |
* @param index For `AttributePart`s, the index to set | |
* @param directiveParent Used internally; should not be set by user | |
*/ | |
const setChildPartValue = (part, value, directiveParent = part) => { | |
part._$setValue(value, directiveParent); | |
return part; | |
}; | |
// A sentinel value that can never appear as a part value except when set by | |
// live(). Used to force a dirty-check to fail and cause a re-render. | |
const RESET_VALUE = {}; | |
/** | |
* Sets the committed value of a ChildPart directly without triggering the | |
* commit stage of the part. | |
* | |
* This is useful in cases where a directive needs to update the part such | |
* that the next update detects a value change or not. When value is omitted, | |
* the next update will be guaranteed to be detected as a change. | |
* | |
* @param part | |
* @param value | |
*/ | |
const setCommittedValue = (part, value = RESET_VALUE) => (part._$committedValue = value); | |
/** | |
* Returns the committed value of a ChildPart. | |
* | |
* The committed value is used for change detection and efficient updates of | |
* the part. It can differ from the value set by the template or directive in | |
* cases where the template value is transformed before being committed. | |
* | |
* - `TemplateResult`s are committed as a `TemplateInstance` | |
* - Iterables are committed as `Array<ChildPart>` | |
* - All other types are committed as the template value or value returned or | |
* set by a directive. | |
* | |
* @param part | |
*/ | |
const getCommittedValue = (part) => part._$committedValue; | |
/** | |
* Removes a ChildPart from the DOM, including any of its content. | |
* | |
* @param part The Part to remove | |
*/ | |
const removePart = (part) => { | |
part._$notifyConnectionChanged?.(false, true); | |
let start = part._$startNode; | |
const end = wrap(part._$endNode).nextSibling; | |
while (start !== end) { | |
const n = wrap(start).nextSibling; | |
wrap(start).remove(); | |
start = n; | |
} | |
}; | |
const clearPart = (part) => { | |
part._$clear(); | |
}; | |
/** | |
* @license | |
* Copyright 2017 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
const PartType = { | |
ATTRIBUTE: 1, | |
CHILD: 2, | |
PROPERTY: 3, | |
BOOLEAN_ATTRIBUTE: 4, | |
EVENT: 5, | |
ELEMENT: 6, | |
}; | |
/** | |
* Creates a user-facing directive function from a Directive class. This | |
* function has the same parameters as the directive's render() method. | |
*/ | |
const directive = (c) => (...values) => ({ | |
// This property needs to remain unminified. | |
['_$litDirective$']: c, | |
values, | |
}); | |
/** | |
* Base class for creating custom directives. Users should extend this class, | |
* implement `render` and/or `update`, and then pass their subclass to | |
* `directive`. | |
*/ | |
class Directive { | |
constructor(_partInfo) { } | |
// See comment in Disconnectable interface for why this is a getter | |
get _$isConnected() { | |
return this._$parent._$isConnected; | |
} | |
/** @internal */ | |
_$initialize(part, parent, attributeIndex) { | |
this.__part = part; | |
this._$parent = parent; | |
this.__attributeIndex = attributeIndex; | |
} | |
/** @internal */ | |
_$resolve(part, props) { | |
return this.update(part, props); | |
} | |
update(_part, props) { | |
return this.render(...props); | |
} | |
} | |
/** | |
* @license | |
* Copyright 2017 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
/** | |
* Recursively walks down the tree of Parts/TemplateInstances/Directives to set | |
* the connected state of directives and run `disconnected`/ `reconnected` | |
* callbacks. | |
* | |
* @return True if there were children to disconnect; false otherwise | |
*/ | |
const notifyChildrenConnectedChanged = (parent, isConnected) => { | |
const children = parent._$disconnectableChildren; | |
if (children === undefined) { | |
return false; | |
} | |
for (const obj of children) { | |
// The existence of `_$notifyDirectiveConnectionChanged` is used as a "brand" to | |
// disambiguate AsyncDirectives from other DisconnectableChildren | |
// (as opposed to using an instanceof check to know when to call it); the | |
// redundancy of "Directive" in the API name is to avoid conflicting with | |
// `_$notifyConnectionChanged`, which exists `ChildParts` which are also in | |
// this list | |
// Disconnect Directive (and any nested directives contained within) | |
// This property needs to remain unminified. | |
obj['_$notifyDirectiveConnectionChanged']?.(isConnected, false); | |
// Disconnect Part/TemplateInstance | |
notifyChildrenConnectedChanged(obj, isConnected); | |
} | |
return true; | |
}; | |
/** | |
* Removes the given child from its parent list of disconnectable children, and | |
* if the parent list becomes empty as a result, removes the parent from its | |
* parent, and so forth up the tree when that causes subsequent parent lists to | |
* become empty. | |
*/ | |
const removeDisconnectableFromParent = (obj) => { | |
let parent, children; | |
do { | |
if ((parent = obj._$parent) === undefined) { | |
break; | |
} | |
children = parent._$disconnectableChildren; | |
children.delete(obj); | |
obj = parent; | |
} while (children?.size === 0); | |
}; | |
const addDisconnectableToParent = (obj) => { | |
// Climb the parent tree, creating a sparse tree of children needing | |
// disconnection | |
for (let parent; (parent = obj._$parent); obj = parent) { | |
let children = parent._$disconnectableChildren; | |
if (children === undefined) { | |
parent._$disconnectableChildren = children = new Set(); | |
} | |
else if (children.has(obj)) { | |
// Once we've reached a parent that already contains this child, we | |
// can short-circuit | |
break; | |
} | |
children.add(obj); | |
installDisconnectAPI(parent); | |
} | |
}; | |
/** | |
* Changes the parent reference of the ChildPart, and updates the sparse tree of | |
* Disconnectable children accordingly. | |
* | |
* Note, this method will be patched onto ChildPart instances and called from | |
* the core code when parts are moved between different parents. | |
*/ | |
function reparentDisconnectables(newParent) { | |
if (this._$disconnectableChildren !== undefined) { | |
removeDisconnectableFromParent(this); | |
this._$parent = newParent; | |
addDisconnectableToParent(this); | |
} | |
else { | |
this._$parent = newParent; | |
} | |
} | |
/** | |
* Sets the connected state on any directives contained within the committed | |
* value of this part (i.e. within a TemplateInstance or iterable of | |
* ChildParts) and runs their `disconnected`/`reconnected`s, as well as within | |
* any directives stored on the ChildPart (when `valueOnly` is false). | |
* | |
* `isClearingValue` should be passed as `true` on a top-level part that is | |
* clearing itself, and not as a result of recursively disconnecting directives | |
* as part of a `clear` operation higher up the tree. This both ensures that any | |
* directive on this ChildPart that produced a value that caused the clear | |
* operation is not disconnected, and also serves as a performance optimization | |
* to avoid needless bookkeeping when a subtree is going away; when clearing a | |
* subtree, only the top-most part need to remove itself from the parent. | |
* | |
* `fromPartIndex` is passed only in the case of a partial `_clear` running as a | |
* result of truncating an iterable. | |
* | |
* Note, this method will be patched onto ChildPart instances and called from the | |
* core code when parts are cleared or the connection state is changed by the | |
* user. | |
*/ | |
function notifyChildPartConnectedChanged(isConnected, isClearingValue = false, fromPartIndex = 0) { | |
const value = this._$committedValue; | |
const children = this._$disconnectableChildren; | |
if (children === undefined || children.size === 0) { | |
return; | |
} | |
if (isClearingValue) { | |
if (Array.isArray(value)) { | |
// Iterable case: Any ChildParts created by the iterable should be | |
// disconnected and removed from this ChildPart's disconnectable | |
// children (starting at `fromPartIndex` in the case of truncation) | |
for (let i = fromPartIndex; i < value.length; i++) { | |
notifyChildrenConnectedChanged(value[i], false); | |
removeDisconnectableFromParent(value[i]); | |
} | |
} | |
else if (value != null) { | |
// TemplateInstance case: If the value has disconnectable children (will | |
// only be in the case that it is a TemplateInstance), we disconnect it | |
// and remove it from this ChildPart's disconnectable children | |
notifyChildrenConnectedChanged(value, false); | |
removeDisconnectableFromParent(value); | |
} | |
} | |
else { | |
notifyChildrenConnectedChanged(this, isConnected); | |
} | |
} | |
/** | |
* Patches disconnection API onto ChildParts. | |
*/ | |
const installDisconnectAPI = (obj) => { | |
if (obj.type == PartType.CHILD) { | |
obj._$notifyConnectionChanged ??= | |
notifyChildPartConnectedChanged; | |
obj._$reparentDisconnectables ??= reparentDisconnectables; | |
} | |
}; | |
/** | |
* An abstract `Directive` base class whose `disconnected` method will be | |
* called when the part containing the directive is cleared as a result of | |
* re-rendering, or when the user calls `part.setConnected(false)` on | |
* a part that was previously rendered containing the directive (as happens | |
* when e.g. a LitElement disconnects from the DOM). | |
* | |
* If `part.setConnected(true)` is subsequently called on a | |
* containing part, the directive's `reconnected` method will be called prior | |
* to its next `update`/`render` callbacks. When implementing `disconnected`, | |
* `reconnected` should also be implemented to be compatible with reconnection. | |
* | |
* Note that updates may occur while the directive is disconnected. As such, | |
* directives should generally check the `this.isConnected` flag during | |
* render/update to determine whether it is safe to subscribe to resources | |
* that may prevent garbage collection. | |
*/ | |
class AsyncDirective extends Directive { | |
constructor() { | |
super(...arguments); | |
// @internal | |
this._$disconnectableChildren = undefined; | |
} | |
/** | |
* Initialize the part with internal fields | |
* @param part | |
* @param parent | |
* @param attributeIndex | |
*/ | |
_$initialize(part, parent, attributeIndex) { | |
super._$initialize(part, parent, attributeIndex); | |
addDisconnectableToParent(this); | |
this.isConnected = part._$isConnected; | |
} | |
// This property needs to remain unminified. | |
/** | |
* Called from the core code when a directive is going away from a part (in | |
* which case `shouldRemoveFromParent` should be true), and from the | |
* `setChildrenConnected` helper function when recursively changing the | |
* connection state of a tree (in which case `shouldRemoveFromParent` should | |
* be false). | |
* | |
* @param isConnected | |
* @param isClearingDirective - True when the directive itself is being | |
* removed; false when the tree is being disconnected | |
* @internal | |
*/ | |
['_$notifyDirectiveConnectionChanged'](isConnected, isClearingDirective = true) { | |
if (isConnected !== this.isConnected) { | |
this.isConnected = isConnected; | |
if (isConnected) { | |
this.reconnected?.(); | |
} | |
else { | |
this.disconnected?.(); | |
} | |
} | |
if (isClearingDirective) { | |
notifyChildrenConnectedChanged(this, isConnected); | |
removeDisconnectableFromParent(this); | |
} | |
} | |
/** | |
* Sets the value of the directive's Part outside the normal `update`/`render` | |
* lifecycle of a directive. | |
* | |
* This method should not be called synchronously from a directive's `update` | |
* or `render`. | |
* | |
* @param directive The directive to update | |
* @param value The value to set | |
*/ | |
setValue(value) { | |
if (isSingleExpression(this.__part)) { | |
this.__part._$setValue(value, this); | |
} | |
else { | |
const newValues = [...this.__part._$committedValue]; | |
newValues[this.__attributeIndex] = value; | |
this.__part._$setValue(newValues, this, 0); | |
} | |
} | |
/** | |
* User callbacks for implementing logic to release any resources/subscriptions | |
* that may have been retained by this directive. Since directives may also be | |
* re-connected, `reconnected` should also be implemented to restore the | |
* working state of the directive prior to the next render. | |
*/ | |
disconnected() { } | |
reconnected() { } | |
} | |
/** | |
* @license | |
* Copyright 2021 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
// Note, this module is not included in package exports so that it's private to | |
// our first-party directives. If it ends up being useful, we can open it up and | |
// export it. | |
/** | |
* Helper to iterate an AsyncIterable in its own closure. | |
* @param iterable The iterable to iterate | |
* @param callback The callback to call for each value. If the callback returns | |
* `false`, the loop will be broken. | |
*/ | |
const forAwaitOf = async (iterable, callback) => { | |
for await (const v of iterable) { | |
if ((await callback(v)) === false) { | |
return; | |
} | |
} | |
}; | |
/** | |
* Holds a reference to an instance that can be disconnected and reconnected, | |
* so that a closure over the ref (e.g. in a then function to a promise) does | |
* not strongly hold a ref to the instance. Approximates a WeakRef but must | |
* be manually connected & disconnected to the backing instance. | |
*/ | |
class PseudoWeakRef { | |
constructor(ref) { | |
this._ref = ref; | |
} | |
/** | |
* Disassociates the ref with the backing instance. | |
*/ | |
disconnect() { | |
this._ref = undefined; | |
} | |
/** | |
* Reassociates the ref with the backing instance. | |
*/ | |
reconnect(ref) { | |
this._ref = ref; | |
} | |
/** | |
* Retrieves the backing instance (will be undefined when disconnected) | |
*/ | |
deref() { | |
return this._ref; | |
} | |
} | |
/** | |
* A helper to pause and resume waiting on a condition in an async function | |
*/ | |
class Pauser { | |
constructor() { | |
this._promise = undefined; | |
this._resolve = undefined; | |
} | |
/** | |
* When paused, returns a promise to be awaited; when unpaused, returns | |
* undefined. Note that in the microtask between the pauser being resumed | |
* an an await of this promise resolving, the pauser could be paused again, | |
* hence callers should check the promise in a loop when awaiting. | |
* @returns A promise to be awaited when paused or undefined | |
*/ | |
get() { | |
return this._promise; | |
} | |
/** | |
* Creates a promise to be awaited | |
*/ | |
pause() { | |
this._promise ??= new Promise((resolve) => (this._resolve = resolve)); | |
} | |
/** | |
* Resolves the promise which may be awaited | |
*/ | |
resume() { | |
this._resolve?.(); | |
this._promise = this._resolve = undefined; | |
} | |
} | |
/** | |
* @license | |
* Copyright 2017 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
class AsyncReplaceDirective extends AsyncDirective { | |
constructor() { | |
super(...arguments); | |
this.__weakThis = new PseudoWeakRef(this); | |
this.__pauser = new Pauser(); | |
} | |
// @ts-expect-error value not used, but we want a nice parameter for docs | |
// eslint-disable-next-line @typescript-eslint/no-unused-vars | |
render(value, _mapper) { | |
return noChange; | |
} | |
update(_part, [value, mapper]) { | |
// If our initial render occurs while disconnected, ensure that the pauser | |
// and weakThis are in the disconnected state | |
if (!this.isConnected) { | |
this.disconnected(); | |
} | |
// If we've already set up this particular iterable, we don't need | |
// to do anything. | |
if (value === this.__value) { | |
return noChange; | |
} | |
this.__value = value; | |
let i = 0; | |
const { __weakThis: weakThis, __pauser: pauser } = this; | |
// Note, the callback avoids closing over `this` so that the directive | |
// can be gc'ed before the promise resolves; instead `this` is retrieved | |
// from `weakThis`, which can break the hard reference in the closure when | |
// the directive disconnects | |
forAwaitOf(value, async (v) => { | |
// The while loop here handles the case that the connection state | |
// thrashes, causing the pauser to resume and then get re-paused | |
while (pauser.get()) { | |
await pauser.get(); | |
} | |
// If the callback gets here and there is no `this`, it means that the | |
// directive has been disconnected and garbage collected and we don't | |
// need to do anything else | |
const _this = weakThis.deref(); | |
if (_this !== undefined) { | |
// Check to make sure that value is the still the current value of | |
// the part, and if not bail because a new value owns this part | |
if (_this.__value !== value) { | |
return false; | |
} | |
// As a convenience, because functional-programming-style | |
// transforms of iterables and async iterables requires a library, | |
// we accept a mapper function. This is especially convenient for | |
// rendering a template for each item. | |
if (mapper !== undefined) { | |
v = mapper(v, i); | |
} | |
_this.commitValue(v, i); | |
i++; | |
} | |
return true; | |
}); | |
return noChange; | |
} | |
// Override point for AsyncAppend to append rather than replace | |
commitValue(value, _index) { | |
this.setValue(value); | |
} | |
disconnected() { | |
this.__weakThis.disconnect(); | |
this.__pauser.pause(); | |
} | |
reconnected() { | |
this.__weakThis.reconnect(this); | |
this.__pauser.resume(); | |
} | |
} | |
/** | |
* A directive that renders the items of an async iterable[1], replacing | |
* previous values with new values, so that only one value is ever rendered | |
* at a time. This directive may be used in any expression type. | |
* | |
* Async iterables are objects with a `[Symbol.asyncIterator]` method, which | |
* returns an iterator who's `next()` method returns a Promise. When a new | |
* value is available, the Promise resolves and the value is rendered to the | |
* Part controlled by the directive. If another value other than this | |
* directive has been set on the Part, the iterable will no longer be listened | |
* to and new values won't be written to the Part. | |
* | |
* [1]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for-await...of | |
* | |
* @param value An async iterable | |
* @param mapper An optional function that maps from (value, index) to another | |
* value. Useful for generating templates for each item in the iterable. | |
*/ | |
const asyncReplace = directive(AsyncReplaceDirective); | |
/** | |
* @license | |
* Copyright 2017 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
class AsyncAppendDirective extends AsyncReplaceDirective { | |
// Override AsyncReplace to narrow the allowed part type to ChildPart only | |
constructor(partInfo) { | |
super(partInfo); | |
if (partInfo.type !== PartType.CHILD) { | |
throw new Error('asyncAppend can only be used in child expressions'); | |
} | |
} | |
// Override AsyncReplace to save the part since we need to append into it | |
update(part, params) { | |
this.__childPart = part; | |
return super.update(part, params); | |
} | |
// Override AsyncReplace to append rather than replace | |
commitValue(value, index) { | |
// When we get the first value, clear the part. This lets the | |
// previous value display until we can replace it. | |
if (index === 0) { | |
clearPart(this.__childPart); | |
} | |
// Create and insert a new part and set its value to the next value | |
const newPart = insertPart(this.__childPart); | |
setChildPartValue(newPart, value); | |
} | |
} | |
/** | |
* A directive that renders the items of an async iterable[1], appending new | |
* values after previous values, similar to the built-in support for iterables. | |
* This directive is usable only in child expressions. | |
* | |
* Async iterables are objects with a [Symbol.asyncIterator] method, which | |
* returns an iterator who's `next()` method returns a Promise. When a new | |
* value is available, the Promise resolves and the value is appended to the | |
* Part controlled by the directive. If another value other than this | |
* directive has been set on the Part, the iterable will no longer be listened | |
* to and new values won't be written to the Part. | |
* | |
* [1]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for-await...of | |
* | |
* @param value An async iterable | |
* @param mapper An optional function that maps from (value, index) to another | |
* value. Useful for generating templates for each item in the iterable. | |
*/ | |
const asyncAppend = directive(AsyncAppendDirective); | |
/** | |
* @license | |
* Copyright 2017 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
/** | |
* The template strings array contents are not compatible between the two | |
* template result types as the compiled template contains a prepared string; | |
* only use the returned template strings array as a cache key. | |
*/ | |
const getStringsFromTemplateResult = (result) => isCompiledTemplateResult(result) ? result['_$litType$'].h : result.strings; | |
class CacheDirective extends Directive { | |
constructor(partInfo) { | |
super(partInfo); | |
this._templateCache = new WeakMap(); | |
} | |
render(v) { | |
// Return an array of the value to induce lit-html to create a ChildPart | |
// for the value that we can move into the cache. | |
return [v]; | |
} | |
update(containerPart, [v]) { | |
const _valueKey = isTemplateResult(this._value) | |
? getStringsFromTemplateResult(this._value) | |
: null; | |
const vKey = isTemplateResult(v) ? getStringsFromTemplateResult(v) : null; | |
// If the previous value is a TemplateResult and the new value is not, | |
// or is a different Template as the previous value, move the child part | |
// into the cache. | |
if (_valueKey !== null && (vKey === null || _valueKey !== vKey)) { | |
// This is always an array because we return [v] in render() | |
const partValue = getCommittedValue(containerPart); | |
const childPart = partValue.pop(); | |
let cachedContainerPart = this._templateCache.get(_valueKey); | |
if (cachedContainerPart === undefined) { | |
const fragment = document.createDocumentFragment(); | |
cachedContainerPart = render(nothing, fragment); | |
cachedContainerPart.setConnected(false); | |
this._templateCache.set(_valueKey, cachedContainerPart); | |
} | |
// Move into cache | |
setCommittedValue(cachedContainerPart, [childPart]); | |
insertPart(cachedContainerPart, undefined, childPart); | |
} | |
// If the new value is a TemplateResult and the previous value is not, | |
// or is a different Template as the previous value, restore the child | |
// part from the cache. | |
if (vKey !== null) { | |
if (_valueKey === null || _valueKey !== vKey) { | |
const cachedContainerPart = this._templateCache.get(vKey); | |
if (cachedContainerPart !== undefined) { | |
// Move the cached part back into the container part value | |
const partValue = getCommittedValue(cachedContainerPart); | |
const cachedPart = partValue.pop(); | |
// Move cached part back into DOM | |
clearPart(containerPart); | |
insertPart(containerPart, undefined, cachedPart); | |
setCommittedValue(containerPart, [cachedPart]); | |
} | |
} | |
// Because vKey is non null, v must be a TemplateResult. | |
this._value = v; | |
} | |
else { | |
this._value = undefined; | |
} | |
return this.render(v); | |
} | |
} | |
/** | |
* Enables fast switching between multiple templates by caching the DOM nodes | |
* and TemplateInstances produced by the templates. | |
* | |
* Example: | |
* | |
* ```js | |
* let checked = false; | |
* | |
* html` | |
* ${cache(checked ? html`input is checked` : html`input is not checked`)} | |
* ` | |
* ``` | |
*/ | |
const cache = directive(CacheDirective); | |
/** | |
* @license | |
* Copyright 2021 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
/** | |
* Chooses and evaluates a template function from a list based on matching | |
* the given `value` to a case. | |
* | |
* Cases are structured as `[caseValue, func]`. `value` is matched to | |
* `caseValue` by strict equality. The first match is selected. Case values | |
* can be of any type including primitives, objects, and symbols. | |
* | |
* This is similar to a switch statement, but as an expression and without | |
* fallthrough. | |
* | |
* @example | |
* | |
* ```ts | |
* render() { | |
* return html` | |
* ${choose(this.section, [ | |
* ['home', () => html`<h1>Home</h1>`], | |
* ['about', () => html`<h1>About</h1>`] | |
* ], | |
* () => html`<h1>Error</h1>`)} | |
* `; | |
* } | |
* ``` | |
*/ | |
const choose = (value, cases, defaultCase) => { | |
for (const c of cases) { | |
const caseValue = c[0]; | |
if (caseValue === value) { | |
const fn = c[1]; | |
return fn(); | |
} | |
} | |
return defaultCase?.(); | |
}; | |
/** | |
* @license | |
* Copyright 2018 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
class ClassMapDirective extends Directive { | |
constructor(partInfo) { | |
super(partInfo); | |
if (partInfo.type !== PartType.ATTRIBUTE || | |
partInfo.name !== 'class' || | |
partInfo.strings?.length > 2) { | |
throw new Error('`classMap()` can only be used in the `class` attribute ' + | |
'and must be the only part in the attribute.'); | |
} | |
} | |
render(classInfo) { | |
// Add spaces to ensure separation from static classes | |
return (' ' + | |
Object.keys(classInfo) | |
.filter((key) => classInfo[key]) | |
.join(' ') + | |
' '); | |
} | |
update(part, [classInfo]) { | |
// Remember dynamic classes on the first render | |
if (this._previousClasses === undefined) { | |
this._previousClasses = new Set(); | |
if (part.strings !== undefined) { | |
this._staticClasses = new Set(part.strings | |
.join(' ') | |
.split(/\s/) | |
.filter((s) => s !== '')); | |
} | |
for (const name in classInfo) { | |
if (classInfo[name] && !this._staticClasses?.has(name)) { | |
this._previousClasses.add(name); | |
} | |
} | |
return this.render(classInfo); | |
} | |
const classList = part.element.classList; | |
// Remove old classes that no longer apply | |
for (const name of this._previousClasses) { | |
if (!(name in classInfo)) { | |
classList.remove(name); | |
this._previousClasses.delete(name); | |
} | |
} | |
// Add or remove classes based on their classMap value | |
for (const name in classInfo) { | |
// We explicitly want a loose truthy check of `value` because it seems | |
// more convenient that '' and 0 are skipped. | |
const value = !!classInfo[name]; | |
if (value !== this._previousClasses.has(name) && | |
!this._staticClasses?.has(name)) { | |
if (value) { | |
classList.add(name); | |
this._previousClasses.add(name); | |
} | |
else { | |
classList.remove(name); | |
this._previousClasses.delete(name); | |
} | |
} | |
} | |
return noChange; | |
} | |
} | |
/** | |
* A directive that applies dynamic CSS classes. | |
* | |
* This must be used in the `class` attribute and must be the only part used in | |
* the attribute. It takes each property in the `classInfo` argument and adds | |
* the property name to the element's `classList` if the property value is | |
* truthy; if the property value is falsey, the property name is removed from | |
* the element's `class`. | |
* | |
* For example `{foo: bar}` applies the class `foo` if the value of `bar` is | |
* truthy. | |
* | |
* @param classInfo | |
*/ | |
const classMap = directive(ClassMapDirective); | |
/** | |
* @license | |
* Copyright 2018 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
// A sentinel that indicates guard() hasn't rendered anything yet | |
const initialValue = {}; | |
class GuardDirective extends Directive { | |
constructor() { | |
super(...arguments); | |
this._previousValue = initialValue; | |
} | |
render(_value, f) { | |
return f(); | |
} | |
update(_part, [value, f]) { | |
if (Array.isArray(value)) { | |
// Dirty-check arrays by item | |
if (Array.isArray(this._previousValue) && | |
this._previousValue.length === value.length && | |
value.every((v, i) => v === this._previousValue[i])) { | |
return noChange; | |
} | |
} | |
else if (this._previousValue === value) { | |
// Dirty-check non-arrays by identity | |
return noChange; | |
} | |
// Copy the value if it's an array so that if it's mutated we don't forget | |
// what the previous values were. | |
this._previousValue = Array.isArray(value) ? Array.from(value) : value; | |
const r = this.render(value, f); | |
return r; | |
} | |
} | |
/** | |
* Prevents re-render of a template function until a single value or an array of | |
* values changes. | |
* | |
* Values are checked against previous values with strict equality (`===`), and | |
* so the check won't detect nested property changes inside objects or arrays. | |
* Arrays values have each item checked against the previous value at the same | |
* index with strict equality. Nested arrays are also checked only by strict | |
* equality. | |
* | |
* Example: | |
* | |
* ```js | |
* html` | |
* <div> | |
* ${guard([user.id, company.id], () => html`...`)} | |
* </div> | |
* ` | |
* ``` | |
* | |
* In this case, the template only rerenders if either `user.id` or `company.id` | |
* changes. | |
* | |
* guard() is useful with immutable data patterns, by preventing expensive work | |
* until data updates. | |
* | |
* Example: | |
* | |
* ```js | |
* html` | |
* <div> | |
* ${guard([immutableItems], () => immutableItems.map(i => html`${i}`))} | |
* </div> | |
* ` | |
* ``` | |
* | |
* In this case, items are mapped over only when the array reference changes. | |
* | |
* @param value the value to check before re-rendering | |
* @param f the template function | |
*/ | |
const guard = directive(GuardDirective); | |
/** | |
* @license | |
* Copyright 2018 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
/** | |
* For AttributeParts, sets the attribute if the value is defined and removes | |
* the attribute if the value is undefined. | |
* | |
* For other part types, this directive is a no-op. | |
*/ | |
const ifDefined = (value) => value ?? nothing; | |
/** | |
* @license | |
* Copyright 2021 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
function* join(items, joiner) { | |
const isFunction = typeof joiner === 'function'; | |
if (items !== undefined) { | |
let i = -1; | |
for (const value of items) { | |
if (i > -1) { | |
yield isFunction ? joiner(i) : joiner; | |
} | |
i++; | |
yield value; | |
} | |
} | |
} | |
/** | |
* @license | |
* Copyright 2021 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
class Keyed extends Directive { | |
constructor() { | |
super(...arguments); | |
this.key = nothing; | |
} | |
render(k, v) { | |
this.key = k; | |
return v; | |
} | |
update(part, [k, v]) { | |
if (k !== this.key) { | |
// Clear the part before returning a value. The one-arg form of | |
// setCommittedValue sets the value to a sentinel which forces a | |
// commit the next render. | |
setCommittedValue(part); | |
this.key = k; | |
} | |
return v; | |
} | |
} | |
/** | |
* Associates a renderable value with a unique key. When the key changes, the | |
* previous DOM is removed and disposed before rendering the next value, even | |
* if the value - such as a template - is the same. | |
* | |
* This is useful for forcing re-renders of stateful components, or working | |
* with code that expects new data to generate new HTML elements, such as some | |
* animation techniques. | |
*/ | |
const keyed = directive(Keyed); | |
/** | |
* @license | |
* Copyright 2020 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
class LiveDirective extends Directive { | |
constructor(partInfo) { | |
super(partInfo); | |
if (!(partInfo.type === PartType.PROPERTY || | |
partInfo.type === PartType.ATTRIBUTE || | |
partInfo.type === PartType.BOOLEAN_ATTRIBUTE)) { | |
throw new Error('The `live` directive is not allowed on child or event bindings'); | |
} | |
if (!isSingleExpression(partInfo)) { | |
throw new Error('`live` bindings can only contain a single expression'); | |
} | |
} | |
render(value) { | |
return value; | |
} | |
update(part, [value]) { | |
if (value === noChange || value === nothing) { | |
return value; | |
} | |
const element = part.element; | |
const name = part.name; | |
if (part.type === PartType.PROPERTY) { | |
// eslint-disable-next-line @typescript-eslint/no-explicit-any | |
if (value === element[name]) { | |
return noChange; | |
} | |
} | |
else if (part.type === PartType.BOOLEAN_ATTRIBUTE) { | |
if (!!value === element.hasAttribute(name)) { | |
return noChange; | |
} | |
} | |
else if (part.type === PartType.ATTRIBUTE) { | |
if (element.getAttribute(name) === String(value)) { | |
return noChange; | |
} | |
} | |
// Resets the part's value, causing its dirty-check to fail so that it | |
// always sets the value. | |
setCommittedValue(part); | |
return value; | |
} | |
} | |
/** | |
* Checks binding values against live DOM values, instead of previously bound | |
* values, when determining whether to update the value. | |
* | |
* This is useful for cases where the DOM value may change from outside of | |
* lit-html, such as with a binding to an `<input>` element's `value` property, | |
* a content editable elements text, or to a custom element that changes it's | |
* own properties or attributes. | |
* | |
* In these cases if the DOM value changes, but the value set through lit-html | |
* bindings hasn't, lit-html won't know to update the DOM value and will leave | |
* it alone. If this is not what you want--if you want to overwrite the DOM | |
* value with the bound value no matter what--use the `live()` directive: | |
* | |
* ```js | |
* html`<input .value=${live(x)}>` | |
* ``` | |
* | |
* `live()` performs a strict equality check against the live DOM value, and if | |
* the new value is equal to the live value, does nothing. This means that | |
* `live()` should not be used when the binding will cause a type conversion. If | |
* you use `live()` with an attribute binding, make sure that only strings are | |
* passed in, or the binding will update every render. | |
*/ | |
const live = directive(LiveDirective); | |
/** | |
* @license | |
* Copyright 2021 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
/** | |
* Returns an iterable containing the result of calling `f(value)` on each | |
* value in `items`. | |
* | |
* @example | |
* | |
* ```ts | |
* render() { | |
* return html` | |
* <ul> | |
* ${map(items, (i) => html`<li>${i}</li>`)} | |
* </ul> | |
* `; | |
* } | |
* ``` | |
*/ | |
function* map(items, f) { | |
if (items !== undefined) { | |
let i = 0; | |
for (const value of items) { | |
yield f(value, i++); | |
} | |
} | |
} | |
/** | |
* @license | |
* Copyright 2021 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
function* range(startOrEnd, end, step = 1) { | |
const start = end === undefined ? 0 : startOrEnd; | |
end ??= startOrEnd; | |
for (let i = start; step > 0 ? i < end : end < i; i += step) { | |
yield i; | |
} | |
} | |
/** | |
* @license | |
* Copyright 2020 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
/** | |
* Creates a new Ref object, which is container for a reference to an element. | |
*/ | |
const createRef = () => new Ref(); | |
/** | |
* An object that holds a ref value. | |
*/ | |
class Ref { | |
} | |
// When callbacks are used for refs, this map tracks the last value the callback | |
// was called with, for ensuring a directive doesn't clear the ref if the ref | |
// has already been rendered to a new spot. It is double-keyed on both the | |
// context (`options.host`) and the callback, since we auto-bind class methods | |
// to `options.host`. | |
const lastElementForContextAndCallback = new WeakMap(); | |
class RefDirective extends AsyncDirective { | |
render(_ref) { | |
return nothing; | |
} | |
update(part, [ref]) { | |
const refChanged = ref !== this._ref; | |
if (refChanged && this._ref !== undefined) { | |
// The ref passed to the directive has changed; | |
// unset the previous ref's value | |
this._updateRefValue(undefined); | |
} | |
if (refChanged || this._lastElementForRef !== this._element) { | |
// We either got a new ref or this is the first render; | |
// store the ref/element & update the ref value | |
this._ref = ref; | |
this._context = part.options?.host; | |
this._updateRefValue((this._element = part.element)); | |
} | |
return nothing; | |
} | |
_updateRefValue(element) { | |
if (typeof this._ref === 'function') { | |
// If the current ref was called with a previous value, call with | |
// `undefined`; We do this to ensure callbacks are called in a consistent | |
// way regardless of whether a ref might be moving up in the tree (in | |
// which case it would otherwise be called with the new value before the | |
// previous one unsets it) and down in the tree (where it would be unset | |
// before being set). Note that element lookup is keyed by | |
// both the context and the callback, since we allow passing unbound | |
// functions that are called on options.host, and we want to treat | |
// these as unique "instances" of a function. | |
const context = this._context ?? globalThis; | |
let lastElementForCallback = lastElementForContextAndCallback.get(context); | |
if (lastElementForCallback === undefined) { | |
lastElementForCallback = new WeakMap(); | |
lastElementForContextAndCallback.set(context, lastElementForCallback); | |
} | |
if (lastElementForCallback.get(this._ref) !== undefined) { | |
this._ref.call(this._context, undefined); | |
} | |
lastElementForCallback.set(this._ref, element); | |
// Call the ref with the new element value | |
if (element !== undefined) { | |
this._ref.call(this._context, element); | |
} | |
} | |
else { | |
this._ref.value = element; | |
} | |
} | |
get _lastElementForRef() { | |
return typeof this._ref === 'function' | |
? lastElementForContextAndCallback | |
.get(this._context ?? globalThis) | |
?.get(this._ref) | |
: this._ref?.value; | |
} | |
disconnected() { | |
// Only clear the box if our element is still the one in it (i.e. another | |
// directive instance hasn't rendered its element to it before us); that | |
// only happens in the event of the directive being cleared (not via manual | |
// disconnection) | |
if (this._lastElementForRef === this._element) { | |
this._updateRefValue(undefined); | |
} | |
} | |
reconnected() { | |
// If we were manually disconnected, we can safely put our element back in | |
// the box, since no rendering could have occurred to change its state | |
this._updateRefValue(this._element); | |
} | |
} | |
/** | |
* Sets the value of a Ref object or calls a ref callback with the element it's | |
* bound to. | |
* | |
* A Ref object acts as a container for a reference to an element. A ref | |
* callback is a function that takes an element as its only argument. | |
* | |
* The ref directive sets the value of the Ref object or calls the ref callback | |
* during rendering, if the referenced element changed. | |
* | |
* Note: If a ref callback is rendered to a different element position or is | |
* removed in a subsequent render, it will first be called with `undefined`, | |
* followed by another call with the new element it was rendered to (if any). | |
* | |
* ```js | |
* // Using Ref object | |
* const inputRef = createRef(); | |
* render(html`<input ${ref(inputRef)}>`, container); | |
* inputRef.value.focus(); | |
* | |
* // Using callback | |
* const callback = (inputElement) => inputElement.focus(); | |
* render(html`<input ${ref(callback)}>`, container); | |
* ``` | |
*/ | |
const ref = directive(RefDirective); | |
/** | |
* @license | |
* Copyright 2017 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
// Helper for generating a map of array item to its index over a subset | |
// of an array (used to lazily generate `newKeyToIndexMap` and | |
// `oldKeyToIndexMap`) | |
const generateMap = (list, start, end) => { | |
const map = new Map(); | |
for (let i = start; i <= end; i++) { | |
map.set(list[i], i); | |
} | |
return map; | |
}; | |
class RepeatDirective extends Directive { | |
constructor(partInfo) { | |
super(partInfo); | |
if (partInfo.type !== PartType.CHILD) { | |
throw new Error('repeat() can only be used in text expressions'); | |
} | |
} | |
_getValuesAndKeys(items, keyFnOrTemplate, template) { | |
let keyFn; | |
if (template === undefined) { | |
template = keyFnOrTemplate; | |
} | |
else if (keyFnOrTemplate !== undefined) { | |
keyFn = keyFnOrTemplate; | |
} | |
const keys = []; | |
const values = []; | |
let index = 0; | |
for (const item of items) { | |
keys[index] = keyFn ? keyFn(item, index) : index; | |
values[index] = template(item, index); | |
index++; | |
} | |
return { | |
values, | |
keys, | |
}; | |
} | |
render(items, keyFnOrTemplate, template) { | |
return this._getValuesAndKeys(items, keyFnOrTemplate, template).values; | |
} | |
update(containerPart, [items, keyFnOrTemplate, template]) { | |
// Old part & key lists are retrieved from the last update (which may | |
// be primed by hydration) | |
const oldParts = getCommittedValue(containerPart); | |
const { values: newValues, keys: newKeys } = this._getValuesAndKeys(items, keyFnOrTemplate, template); | |
// We check that oldParts, the committed value, is an Array as an | |
// indicator that the previous value came from a repeat() call. If | |
// oldParts is not an Array then this is the first render and we return | |
// an array for lit-html's array handling to render, and remember the | |
// keys. | |
if (!Array.isArray(oldParts)) { | |
this._itemKeys = newKeys; | |
return newValues; | |
} | |
// In SSR hydration it's possible for oldParts to be an array but for us | |
// to not have item keys because the update() hasn't run yet. We set the | |
// keys to an empty array. This will cause all oldKey/newKey comparisons | |
// to fail and execution to fall to the last nested brach below which | |
// reuses the oldPart. | |
const oldKeys = (this._itemKeys ??= []); | |
// New part list will be built up as we go (either reused from | |
// old parts or created for new keys in this update). This is | |
// saved in the above cache at the end of the update. | |
const newParts = []; | |
// Maps from key to index for current and previous update; these | |
// are generated lazily only when needed as a performance | |
// optimization, since they are only required for multiple | |
// non-contiguous changes in the list, which are less common. | |
let newKeyToIndexMap; | |
let oldKeyToIndexMap; | |
// Head and tail pointers to old parts and new values | |
let oldHead = 0; | |
let oldTail = oldParts.length - 1; | |
let newHead = 0; | |
let newTail = newValues.length - 1; | |
// Overview of O(n) reconciliation algorithm (general approach | |
// based on ideas found in ivi, vue, snabbdom, etc.): | |
// | |
// * We start with the list of old parts and new values (and | |
// arrays of their respective keys), head/tail pointers into | |
// each, and we build up the new list of parts by updating | |
// (and when needed, moving) old parts or creating new ones. | |
// The initial scenario might look like this (for brevity of | |
// the diagrams, the numbers in the array reflect keys | |
// associated with the old parts or new values, although keys | |
// and parts/values are actually stored in parallel arrays | |
// indexed using the same head/tail pointers): | |
// | |
// oldHead v v oldTail | |
// oldKeys: [0, 1, 2, 3, 4, 5, 6] | |
// newParts: [ , , , , , , ] | |
// newKeys: [0, 2, 1, 4, 3, 7, 6] <- reflects the user's new | |
// item order | |
// newHead ^ ^ newTail | |
// | |
// * Iterate old & new lists from both sides, updating, | |
// swapping, or removing parts at the head/tail locations | |
// until neither head nor tail can move. | |
// | |
// * Example below: keys at head pointers match, so update old | |
// part 0 in-place (no need to move it) and record part 0 in | |
// the `newParts` list. The last thing we do is advance the | |
// `oldHead` and `newHead` pointers (will be reflected in the | |
// next diagram). | |
// | |
// oldHead v v oldTail | |
// oldKeys: [0, 1, 2, 3, 4, 5, 6] | |
// newParts: [0, , , , , , ] <- heads matched: update 0 | |
// newKeys: [0, 2, 1, 4, 3, 7, 6] and advance both oldHead | |
// & newHead | |
// newHead ^ ^ newTail | |
// | |
// * Example below: head pointers don't match, but tail | |
// pointers do, so update part 6 in place (no need to move | |
// it), and record part 6 in the `newParts` list. Last, | |
// advance the `oldTail` and `oldHead` pointers. | |
// | |
// oldHead v v oldTail | |
// oldKeys: [0, 1, 2, 3, 4, 5, 6] | |
// newParts: [0, , , , , , 6] <- tails matched: update 6 | |
// newKeys: [0, 2, 1, 4, 3, 7, 6] and advance both oldTail | |
// & newTail | |
// newHead ^ ^ newTail | |
// | |
// * If neither head nor tail match; next check if one of the | |
// old head/tail items was removed. We first need to generate | |
// the reverse map of new keys to index (`newKeyToIndexMap`), | |
// which is done once lazily as a performance optimization, | |
// since we only hit this case if multiple non-contiguous | |
// changes were made. Note that for contiguous removal | |
// anywhere in the list, the head and tails would advance | |
// from either end and pass each other before we get to this | |
// case and removals would be handled in the final while loop | |
// without needing to generate the map. | |
// | |
// * Example below: The key at `oldTail` was removed (no longer | |
// in the `newKeyToIndexMap`), so remove that part from the | |
// DOM and advance just the `oldTail` pointer. | |
// | |
// oldHead v v oldTail | |
// oldKeys: [0, 1, 2, 3, 4, 5, 6] | |
// newParts: [0, , , , , , 6] <- 5 not in new map: remove | |
// newKeys: [0, 2, 1, 4, 3, 7, 6] 5 and advance oldTail | |
// newHead ^ ^ newTail | |
// | |
// * Once head and tail cannot move, any mismatches are due to | |
// either new or moved items; if a new key is in the previous | |
// "old key to old index" map, move the old part to the new | |
// location, otherwise create and insert a new part. Note | |
// that when moving an old part we null its position in the | |
// oldParts array if it lies between the head and tail so we | |
// know to skip it when the pointers get there. | |
// | |
// * Example below: neither head nor tail match, and neither | |
// were removed; so find the `newHead` key in the | |
// `oldKeyToIndexMap`, and move that old part's DOM into the | |
// next head position (before `oldParts[oldHead]`). Last, | |
// null the part in the `oldPart` array since it was | |
// somewhere in the remaining oldParts still to be scanned | |
// (between the head and tail pointers) so that we know to | |
// skip that old part on future iterations. | |
// | |
// oldHead v v oldTail | |
// oldKeys: [0, 1, -, 3, 4, 5, 6] | |
// newParts: [0, 2, , , , , 6] <- stuck: update & move 2 | |
// newKeys: [0, 2, 1, 4, 3, 7, 6] into place and advance | |
// newHead | |
// newHead ^ ^ newTail | |
// | |
// * Note that for moves/insertions like the one above, a part | |
// inserted at the head pointer is inserted before the | |
// current `oldParts[oldHead]`, and a part inserted at the | |
// tail pointer is inserted before `newParts[newTail+1]`. The | |
// seeming asymmetry lies in the fact that new parts are | |
// moved into place outside in, so to the right of the head | |
// pointer are old parts, and to the right of the tail | |
// pointer are new parts. | |
// | |
// * We always restart back from the top of the algorithm, | |
// allowing matching and simple updates in place to | |
// continue... | |
// | |
// * Example below: the head pointers once again match, so | |
// simply update part 1 and record it in the `newParts` | |
// array. Last, advance both head pointers. | |
// | |
// oldHead v v oldTail | |
// oldKeys: [0, 1, -, 3, 4, 5, 6] | |
// newParts: [0, 2, 1, , , , 6] <- heads matched: update 1 | |
// newKeys: [0, 2, 1, 4, 3, 7, 6] and advance both oldHead | |
// & newHead | |
// newHead ^ ^ newTail | |
// | |
// * As mentioned above, items that were moved as a result of | |
// being stuck (the final else clause in the code below) are | |
// marked with null, so we always advance old pointers over | |
// these so we're comparing the next actual old value on | |
// either end. | |
// | |
// * Example below: `oldHead` is null (already placed in | |
// newParts), so advance `oldHead`. | |
// | |
// oldHead v v oldTail | |
// oldKeys: [0, 1, -, 3, 4, 5, 6] <- old head already used: | |
// newParts: [0, 2, 1, , , , 6] advance oldHead | |
// newKeys: [0, 2, 1, 4, 3, 7, 6] | |
// newHead ^ ^ newTail | |
// | |
// * Note it's not critical to mark old parts as null when they | |
// are moved from head to tail or tail to head, since they | |
// will be outside the pointer range and never visited again. | |
// | |
// * Example below: Here the old tail key matches the new head | |
// key, so the part at the `oldTail` position and move its | |
// DOM to the new head position (before `oldParts[oldHead]`). | |
// Last, advance `oldTail` and `newHead` pointers. | |
// | |
// oldHead v v oldTail | |
// oldKeys: [0, 1, -, 3, 4, 5, 6] | |
// newParts: [0, 2, 1, 4, , , 6] <- old tail matches new | |
// newKeys: [0, 2, 1, 4, 3, 7, 6] head: update & move 4, | |
// advance oldTail & newHead | |
// newHead ^ ^ newTail | |
// | |
// * Example below: Old and new head keys match, so update the | |
// old head part in place, and advance the `oldHead` and | |
// `newHead` pointers. | |
// | |
// oldHead v oldTail | |
// oldKeys: [0, 1, -, 3, 4, 5, 6] | |
// newParts: [0, 2, 1, 4, 3, ,6] <- heads match: update 3 | |
// newKeys: [0, 2, 1, 4, 3, 7, 6] and advance oldHead & | |
// newHead | |
// newHead ^ ^ newTail | |
// | |
// * Once the new or old pointers move past each other then all | |
// we have left is additions (if old list exhausted) or | |
// removals (if new list exhausted). Those are handled in the | |
// final while loops at the end. | |
// | |
// * Example below: `oldHead` exceeded `oldTail`, so we're done | |
// with the main loop. Create the remaining part and insert | |
// it at the new head position, and the update is complete. | |
// | |
// (oldHead > oldTail) | |
// oldKeys: [0, 1, -, 3, 4, 5, 6] | |
// newParts: [0, 2, 1, 4, 3, 7 ,6] <- create and insert 7 | |
// newKeys: [0, 2, 1, 4, 3, 7, 6] | |
// newHead ^ newTail | |
// | |
// * Note that the order of the if/else clauses is not | |
// important to the algorithm, as long as the null checks | |
// come first (to ensure we're always working on valid old | |
// parts) and that the final else clause comes last (since | |
// that's where the expensive moves occur). The order of | |
// remaining clauses is is just a simple guess at which cases | |
// will be most common. | |
// | |
// * Note, we could calculate the longest | |
// increasing subsequence (LIS) of old items in new position, | |
// and only move those not in the LIS set. However that costs | |
// O(nlogn) time and adds a bit more code, and only helps | |
// make rare types of mutations require fewer moves. The | |
// above handles removes, adds, reversal, swaps, and single | |
// moves of contiguous items in linear time, in the minimum | |
// number of moves. As the number of multiple moves where LIS | |
// might help approaches a random shuffle, the LIS | |
// optimization becomes less helpful, so it seems not worth | |
// the code at this point. Could reconsider if a compelling | |
// case arises. | |
while (oldHead <= oldTail && newHead <= newTail) { | |
if (oldParts[oldHead] === null) { | |
// `null` means old part at head has already been used | |
// below; skip | |
oldHead++; | |
} | |
else if (oldParts[oldTail] === null) { | |
// `null` means old part at tail has already been used | |
// below; skip | |
oldTail--; | |
} | |
else if (oldKeys[oldHead] === newKeys[newHead]) { | |
// Old head matches new head; update in place | |
newParts[newHead] = setChildPartValue(oldParts[oldHead], newValues[newHead]); | |
oldHead++; | |
newHead++; | |
} | |
else if (oldKeys[oldTail] === newKeys[newTail]) { | |
// Old tail matches new tail; update in place | |
newParts[newTail] = setChildPartValue(oldParts[oldTail], newValues[newTail]); | |
oldTail--; | |
newTail--; | |
} | |
else if (oldKeys[oldHead] === newKeys[newTail]) { | |
// Old head matches new tail; update and move to new tail | |
newParts[newTail] = setChildPartValue(oldParts[oldHead], newValues[newTail]); | |
insertPart(containerPart, newParts[newTail + 1], oldParts[oldHead]); | |
oldHead++; | |
newTail--; | |
} | |
else if (oldKeys[oldTail] === newKeys[newHead]) { | |
// Old tail matches new head; update and move to new head | |
newParts[newHead] = setChildPartValue(oldParts[oldTail], newValues[newHead]); | |
insertPart(containerPart, oldParts[oldHead], oldParts[oldTail]); | |
oldTail--; | |
newHead++; | |
} | |
else { | |
if (newKeyToIndexMap === undefined) { | |
// Lazily generate key-to-index maps, used for removals & | |
// moves below | |
newKeyToIndexMap = generateMap(newKeys, newHead, newTail); | |
oldKeyToIndexMap = generateMap(oldKeys, oldHead, oldTail); | |
} | |
if (!newKeyToIndexMap.has(oldKeys[oldHead])) { | |
// Old head is no longer in new list; remove | |
removePart(oldParts[oldHead]); | |
oldHead++; | |
} | |
else if (!newKeyToIndexMap.has(oldKeys[oldTail])) { | |
// Old tail is no longer in new list; remove | |
removePart(oldParts[oldTail]); | |
oldTail--; | |
} | |
else { | |
// Any mismatches at this point are due to additions or | |
// moves; see if we have an old part we can reuse and move | |
// into place | |
const oldIndex = oldKeyToIndexMap.get(newKeys[newHead]); | |
const oldPart = oldIndex !== undefined ? oldParts[oldIndex] : null; | |
if (oldPart === null) { | |
// No old part for this value; create a new one and | |
// insert it | |
const newPart = insertPart(containerPart, oldParts[oldHead]); | |
setChildPartValue(newPart, newValues[newHead]); | |
newParts[newHead] = newPart; | |
} | |
else { | |
// Reuse old part | |
newParts[newHead] = setChildPartValue(oldPart, newValues[newHead]); | |
insertPart(containerPart, oldParts[oldHead], oldPart); | |
// This marks the old part as having been used, so that | |
// it will be skipped in the first two checks above | |
oldParts[oldIndex] = null; | |
} | |
newHead++; | |
} | |
} | |
} | |
// Add parts for any remaining new values | |
while (newHead <= newTail) { | |
// For all remaining additions, we insert before last new | |
// tail, since old pointers are no longer valid | |
const newPart = insertPart(containerPart, newParts[newTail + 1]); | |
setChildPartValue(newPart, newValues[newHead]); | |
newParts[newHead++] = newPart; | |
} | |
// Remove any remaining unused old parts | |
while (oldHead <= oldTail) { | |
const oldPart = oldParts[oldHead++]; | |
if (oldPart !== null) { | |
removePart(oldPart); | |
} | |
} | |
// Save order of new parts for next round | |
this._itemKeys = newKeys; | |
// Directly set part value, bypassing it's dirty-checking | |
setCommittedValue(containerPart, newParts); | |
return noChange; | |
} | |
} | |
/** | |
* A directive that repeats a series of values (usually `TemplateResults`) | |
* generated from an iterable, and updates those items efficiently when the | |
* iterable changes based on user-provided `keys` associated with each item. | |
* | |
* Note that if a `keyFn` is provided, strict key-to-DOM mapping is maintained, | |
* meaning previous DOM for a given key is moved into the new position if | |
* needed, and DOM will never be reused with values for different keys (new DOM | |
* will always be created for new keys). This is generally the most efficient | |
* way to use `repeat` since it performs minimum unnecessary work for insertions | |
* and removals. | |
* | |
* The `keyFn` takes two parameters, the item and its index, and returns a unique key value. | |
* | |
* ```js | |
* html` | |
* <ol> | |
* ${repeat(this.items, (item) => item.id, (item, index) => { | |
* return html`<li>${index}: ${item.name}</li>`; | |
* })} | |
* </ol> | |
* ` | |
* ``` | |
* | |
* **Important**: If providing a `keyFn`, keys *must* be unique for all items in a | |
* given call to `repeat`. The behavior when two or more items have the same key | |
* is undefined. | |
* | |
* If no `keyFn` is provided, this directive will perform similar to mapping | |
* items to values, and DOM will be reused against potentially different items. | |
*/ | |
const repeat = directive(RepeatDirective); | |
/** | |
* @license | |
* Copyright 2018 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
const important = 'important'; | |
// The leading space is important | |
const importantFlag = ' !' + important; | |
// How many characters to remove from a value, as a negative number | |
const flagTrim = 0 - importantFlag.length; | |
class StyleMapDirective extends Directive { | |
constructor(partInfo) { | |
super(partInfo); | |
if (partInfo.type !== PartType.ATTRIBUTE || | |
partInfo.name !== 'style' || | |
partInfo.strings?.length > 2) { | |
throw new Error('The `styleMap` directive must be used in the `style` attribute ' + | |
'and must be the only part in the attribute.'); | |
} | |
} | |
render(styleInfo) { | |
return Object.keys(styleInfo).reduce((style, prop) => { | |
const value = styleInfo[prop]; | |
if (value == null) { | |
return style; | |
} | |
// Convert property names from camel-case to dash-case, i.e.: | |
// `backgroundColor` -> `background-color` | |
// Vendor-prefixed names need an extra `-` appended to front: | |
// `webkitAppearance` -> `-webkit-appearance` | |
// Exception is any property name containing a dash, including | |
// custom properties; we assume these are already dash-cased i.e.: | |
// `--my-button-color` --> `--my-button-color` | |
prop = prop.includes('-') | |
? prop | |
: prop | |
.replace(/(?:^(webkit|moz|ms|o)|)(?=[A-Z])/g, '-$&') | |
.toLowerCase(); | |
return style + `${prop}:${value};`; | |
}, ''); | |
} | |
update(part, [styleInfo]) { | |
const { style } = part.element; | |
if (this._previousStyleProperties === undefined) { | |
this._previousStyleProperties = new Set(Object.keys(styleInfo)); | |
return this.render(styleInfo); | |
} | |
// Remove old properties that no longer exist in styleInfo | |
for (const name of this._previousStyleProperties) { | |
// If the name isn't in styleInfo or it's null/undefined | |
if (styleInfo[name] == null) { | |
this._previousStyleProperties.delete(name); | |
if (name.includes('-')) { | |
style.removeProperty(name); | |
} | |
else { | |
// eslint-disable-next-line @typescript-eslint/no-explicit-any | |
style[name] = null; | |
} | |
} | |
} | |
// Add or update properties | |
for (const name in styleInfo) { | |
const value = styleInfo[name]; | |
if (value != null) { | |
this._previousStyleProperties.add(name); | |
const isImportant = typeof value === 'string' && value.endsWith(importantFlag); | |
if (name.includes('-') || isImportant) { | |
style.setProperty(name, isImportant | |
? value.slice(0, flagTrim) | |
: value, isImportant ? important : ''); | |
} | |
else { | |
// eslint-disable-next-line @typescript-eslint/no-explicit-any | |
style[name] = value; | |
} | |
} | |
} | |
return noChange; | |
} | |
} | |
/** | |
* A directive that applies CSS properties to an element. | |
* | |
* `styleMap` can only be used in the `style` attribute and must be the only | |
* expression in the attribute. It takes the property names in the | |
* {@link StyleInfo styleInfo} object and adds the properties to the inline | |
* style of the element. | |
* | |
* Property names with dashes (`-`) are assumed to be valid CSS | |
* property names and set on the element's style object using `setProperty()`. | |
* Names without dashes are assumed to be camelCased JavaScript property names | |
* and set on the element's style object using property assignment, allowing the | |
* style object to translate JavaScript-style names to CSS property names. | |
* | |
* For example `styleMap({backgroundColor: 'red', 'border-top': '5px', '--size': | |
* '0'})` sets the `background-color`, `border-top` and `--size` properties. | |
* | |
* @param styleInfo | |
* @see {@link https://lit.dev/docs/templates/directives/#stylemap styleMap code samples on Lit.dev} | |
*/ | |
const styleMap = directive(StyleMapDirective); | |
/** | |
* @license | |
* Copyright 2020 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
class TemplateContentDirective extends Directive { | |
constructor(partInfo) { | |
super(partInfo); | |
if (partInfo.type !== PartType.CHILD) { | |
throw new Error('templateContent can only be used in child bindings'); | |
} | |
} | |
render(template) { | |
if (this._previousTemplate === template) { | |
return noChange; | |
} | |
this._previousTemplate = template; | |
return document.importNode(template.content, true); | |
} | |
} | |
/** | |
* Renders the content of a template element as HTML. | |
* | |
* Note, the template should be developer controlled and not user controlled. | |
* Rendering a user-controlled template with this directive | |
* could lead to cross-site-scripting vulnerabilities. | |
*/ | |
const templateContent = directive(TemplateContentDirective); | |
/** | |
* @license | |
* Copyright 2017 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
const HTML_RESULT = 1; | |
class UnsafeHTMLDirective extends Directive { | |
constructor(partInfo) { | |
super(partInfo); | |
this._value = nothing; | |
if (partInfo.type !== PartType.CHILD) { | |
throw new Error(`${this.constructor.directiveName}() can only be used in child bindings`); | |
} | |
} | |
render(value) { | |
if (value === nothing || value == null) { | |
this._templateResult = undefined; | |
return (this._value = value); | |
} | |
if (value === noChange) { | |
return value; | |
} | |
if (typeof value != 'string') { | |
throw new Error(`${this.constructor.directiveName}() called with a non-string value`); | |
} | |
if (value === this._value) { | |
return this._templateResult; | |
} | |
this._value = value; | |
const strings = [value]; | |
// eslint-disable-next-line @typescript-eslint/no-explicit-any | |
strings.raw = strings; | |
// WARNING: impersonating a TemplateResult like this is extremely | |
// dangerous. Third-party directives should not do this. | |
return (this._templateResult = { | |
// Cast to a known set of integers that satisfy ResultType so that we | |
// don't have to export ResultType and possibly encourage this pattern. | |
// This property needs to remain unminified. | |
['_$litType$']: this.constructor | |
.resultType, | |
strings, | |
values: [], | |
}); | |
} | |
} | |
UnsafeHTMLDirective.directiveName = 'unsafeHTML'; | |
UnsafeHTMLDirective.resultType = HTML_RESULT; | |
/** | |
* Renders the result as HTML, rather than text. | |
* | |
* The values `undefined`, `null`, and `nothing`, will all result in no content | |
* (empty string) being rendered. | |
* | |
* Note, this is unsafe to use with any user-provided input that hasn't been | |
* sanitized or escaped, as it may lead to cross-site-scripting | |
* vulnerabilities. | |
*/ | |
const unsafeHTML = directive(UnsafeHTMLDirective); | |
/** | |
* @license | |
* Copyright 2017 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
const SVG_RESULT = 2; | |
class UnsafeSVGDirective extends UnsafeHTMLDirective { | |
} | |
UnsafeSVGDirective.directiveName = 'unsafeSVG'; | |
UnsafeSVGDirective.resultType = SVG_RESULT; | |
/** | |
* Renders the result as SVG, rather than text. | |
* | |
* The values `undefined`, `null`, and `nothing`, will all result in no content | |
* (empty string) being rendered. | |
* | |
* Note, this is unsafe to use with any user-provided input that hasn't been | |
* sanitized or escaped, as it may lead to cross-site-scripting | |
* vulnerabilities. | |
*/ | |
const unsafeSVG = directive(UnsafeSVGDirective); | |
/** | |
* @license | |
* Copyright 2017 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
const isPromise = (x) => { | |
return !isPrimitive(x) && typeof x.then === 'function'; | |
}; | |
// Effectively infinity, but a SMI. | |
const _infinity = 0x3fffffff; | |
class UntilDirective extends AsyncDirective { | |
constructor() { | |
super(...arguments); | |
this.__lastRenderedIndex = _infinity; | |
this.__values = []; | |
this.__weakThis = new PseudoWeakRef(this); | |
this.__pauser = new Pauser(); | |
} | |
render(...args) { | |
return args.find((x) => !isPromise(x)) ?? noChange; | |
} | |
update(_part, args) { | |
const previousValues = this.__values; | |
let previousLength = previousValues.length; | |
this.__values = args; | |
const weakThis = this.__weakThis; | |
const pauser = this.__pauser; | |
// If our initial render occurs while disconnected, ensure that the pauser | |
// and weakThis are in the disconnected state | |
if (!this.isConnected) { | |
this.disconnected(); | |
} | |
for (let i = 0; i < args.length; i++) { | |
// If we've rendered a higher-priority value already, stop. | |
if (i > this.__lastRenderedIndex) { | |
break; | |
} | |
const value = args[i]; | |
// Render non-Promise values immediately | |
if (!isPromise(value)) { | |
this.__lastRenderedIndex = i; | |
// Since a lower-priority value will never overwrite a higher-priority | |
// synchronous value, we can stop processing now. | |
return value; | |
} | |
// If this is a Promise we've already handled, skip it. | |
if (i < previousLength && value === previousValues[i]) { | |
continue; | |
} | |
// We have a Promise that we haven't seen before, so priorities may have | |
// changed. Forget what we rendered before. | |
this.__lastRenderedIndex = _infinity; | |
previousLength = 0; | |
// Note, the callback avoids closing over `this` so that the directive | |
// can be gc'ed before the promise resolves; instead `this` is retrieved | |
// from `weakThis`, which can break the hard reference in the closure when | |
// the directive disconnects | |
Promise.resolve(value).then(async (result) => { | |
// If we're disconnected, wait until we're (maybe) reconnected | |
// The while loop here handles the case that the connection state | |
// thrashes, causing the pauser to resume and then get re-paused | |
while (pauser.get()) { | |
await pauser.get(); | |
} | |
// If the callback gets here and there is no `this`, it means that the | |
// directive has been disconnected and garbage collected and we don't | |
// need to do anything else | |
const _this = weakThis.deref(); | |
if (_this !== undefined) { | |
const index = _this.__values.indexOf(value); | |
// If state.values doesn't contain the value, we've re-rendered without | |
// the value, so don't render it. Then, only render if the value is | |
// higher-priority than what's already been rendered. | |
if (index > -1 && index < _this.__lastRenderedIndex) { | |
_this.__lastRenderedIndex = index; | |
_this.setValue(result); | |
} | |
} | |
}); | |
} | |
return noChange; | |
} | |
disconnected() { | |
this.__weakThis.disconnect(); | |
this.__pauser.pause(); | |
} | |
reconnected() { | |
this.__weakThis.reconnect(this); | |
this.__pauser.resume(); | |
} | |
} | |
/** | |
* Renders one of a series of values, including Promises, to a Part. | |
* | |
* Values are rendered in priority order, with the first argument having the | |
* highest priority and the last argument having the lowest priority. If a | |
* value is a Promise, low-priority values will be rendered until it resolves. | |
* | |
* The priority of values can be used to create placeholder content for async | |
* data. For example, a Promise with pending content can be the first, | |
* highest-priority, argument, and a non_promise loading indicator template can | |
* be used as the second, lower-priority, argument. The loading indicator will | |
* render immediately, and the primary content will render when the Promise | |
* resolves. | |
* | |
* Example: | |
* | |
* ```js | |
* const content = fetch('./content.txt').then(r => r.text()); | |
* html`${until(content, html`<span>Loading...</span>`)}` | |
* ``` | |
*/ | |
const until = directive(UntilDirective); | |
/** | |
* The type of the class that powers this directive. Necessary for naming the | |
* directive's return type. | |
*/ | |
// export type {UntilDirective}; | |
/** | |
* @license | |
* Copyright 2021 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
function when(condition, trueCase, falseCase) { | |
return condition ? trueCase(condition) : falseCase?.(condition); | |
} | |
/** | |
* @license | |
* Copyright 2020 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
/** | |
* Prevents JSON injection attacks. | |
* | |
* The goals of this brand: | |
* 1) fast to check | |
* 2) code is small on the wire | |
* 3) multiple versions of Lit in a single page will all produce mutually | |
* interoperable StaticValues | |
* 4) normal JSON.parse (without an unusual reviver) can not produce a | |
* StaticValue | |
* | |
* Symbols satisfy (1), (2), and (4). We use Symbol.for to satisfy (3), but | |
* we don't care about the key, so we break ties via (2) and use the empty | |
* string. | |
*/ | |
const brand = Symbol.for(''); | |
/** Safely extracts the string part of a StaticValue. */ | |
const unwrapStaticValue = (value) => { | |
if (value?.r !== brand) { | |
return undefined; | |
} | |
return value?.['_$litStatic$']; | |
}; | |
/** | |
* Wraps a string so that it behaves like part of the static template | |
* strings instead of a dynamic value. | |
* | |
* Users must take care to ensure that adding the static string to the template | |
* results in well-formed HTML, or else templates may break unexpectedly. | |
* | |
* Note that this function is unsafe to use on untrusted content, as it will be | |
* directly parsed into HTML. Do not pass user input to this function | |
* without sanitizing it. | |
* | |
* Static values can be changed, but they will cause a complete re-render | |
* since they effectively create a new template. | |
*/ | |
const unsafeStatic = (value) => ({ | |
['_$litStatic$']: value, | |
r: brand, | |
}); | |
const textFromStatic = (value) => { | |
if (value['_$litStatic$'] !== undefined) { | |
return value['_$litStatic$']; | |
} | |
else { | |
throw new Error(`Value passed to 'literal' function must be a 'literal' result: ${value}. Use 'unsafeStatic' to pass non-literal values, but | |
take care to ensure page security.`); | |
} | |
}; | |
/** | |
* Tags a string literal so that it behaves like part of the static template | |
* strings instead of a dynamic value. | |
* | |
* The only values that may be used in template expressions are other tagged | |
* `literal` results or `unsafeStatic` values (note that untrusted content | |
* should never be passed to `unsafeStatic`). | |
* | |
* Users must take care to ensure that adding the static string to the template | |
* results in well-formed HTML, or else templates may break unexpectedly. | |
* | |
* Static values can be changed, but they will cause a complete re-render since | |
* they effectively create a new template. | |
*/ | |
const literal = (strings, ...values) => ({ | |
['_$litStatic$']: values.reduce((acc, v, idx) => acc + textFromStatic(v) + strings[idx + 1], strings[0]), | |
r: brand, | |
}); | |
const stringsCache = new Map(); | |
/** | |
* Wraps a lit-html template tag (`html` or `svg`) to add static value support. | |
*/ | |
const withStatic = (coreTag) => (strings, ...values) => { | |
const l = values.length; | |
let staticValue; | |
let dynamicValue; | |
const staticStrings = []; | |
const dynamicValues = []; | |
let i = 0; | |
let hasStatics = false; | |
let s; | |
while (i < l) { | |
s = strings[i]; | |
// Collect any unsafeStatic values, and their following template strings | |
// so that we treat a run of template strings and unsafe static values as | |
// a single template string. | |
while (i < l && | |
((dynamicValue = values[i]), | |
(staticValue = unwrapStaticValue(dynamicValue))) !== undefined) { | |
s += staticValue + strings[++i]; | |
hasStatics = true; | |
} | |
// If the last value is static, we don't need to push it. | |
if (i !== l) { | |
dynamicValues.push(dynamicValue); | |
} | |
staticStrings.push(s); | |
i++; | |
} | |
// If the last value isn't static (which would have consumed the last | |
// string), then we need to add the last string. | |
if (i === l) { | |
staticStrings.push(strings[l]); | |
} | |
if (hasStatics) { | |
const key = staticStrings.join('$$lit$$'); | |
strings = stringsCache.get(key); | |
if (strings === undefined) { | |
// Beware: in general this pattern is unsafe, and doing so may bypass | |
// lit's security checks and allow an attacker to execute arbitrary | |
// code and inject arbitrary content. | |
// eslint-disable-next-line @typescript-eslint/no-explicit-any | |
staticStrings.raw = staticStrings; | |
stringsCache.set(key, (strings = staticStrings)); | |
} | |
values = dynamicValues; | |
} | |
return coreTag(strings, ...values); | |
}; | |
/** | |
* Interprets a template literal as an HTML template that can efficiently | |
* render to and update a container. | |
* | |
* Includes static value support from `lit-html/static.js`. | |
*/ | |
const html = withStatic(html$1); | |
/** | |
* Interprets a template literal as an SVG template that can efficiently | |
* render to and update a container. | |
* | |
* Includes static value support from `lit-html/static.js`. | |
*/ | |
const svg = withStatic(svg$1); | |
/** | |
* @license | |
* Copyright 2021 Google LLC | |
* SPDX-License-Identifier: BSD-3-Clause | |
*/ | |
if (!window.litDisableBundleWarning) { | |
console.warn('Lit has been loaded from a bundle that combines all core features into ' + | |
'a single file. To reduce transfer size and parsing cost, consider ' + | |
'using the `lit` npm package directly in your project.'); | |
} | |
export { AsyncDirective, AsyncReplaceDirective, CSSResult, Directive, LitElement, PartType, ReactiveElement, TemplateResultType, UnsafeHTMLDirective, UntilDirective, _$LE, _$LH, adoptStyles, asyncAppend, asyncReplace, cache, choose, classMap, clearPart, createRef, css, defaultConverter, directive, getCommittedValue, getCompatibleStyle, getDirectiveClass, guard, html$1 as html, ifDefined, insertPart, isCompiledTemplateResult, isDirectiveResult, isPrimitive, isServer, isSingleExpression, isTemplateResult, join, keyed, literal, live, map, noChange, notEqual, nothing, range, ref, removePart, render, repeat, setChildPartValue, setCommittedValue, html as staticHtml, svg as staticSvg, styleMap, supportsAdoptingStyleSheets, svg$1 as svg, templateContent, unsafeCSS, unsafeHTML, unsafeSVG, unsafeStatic, until, when, withStatic }; | |
//# sourceMappingURL=lit-all.min.js.map |
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