Small module for converting Luau code to Stylesheet instances.r

BaseStyleSheet.luau

return {
	Name = "BaseStyleSheet",
	DeriveFromBase = false,
	Rules = {
		CanvasGroup = {
			Priority = 9,
			BackgroundColor3 = Color3.new(1,1,1),
			BorderColor3 = Color3.new(0,0,0),
			BorderSizePixel = 0,
			Size = UDim2.fromOffset(100, 100)
		},

		Frame = {
			Priority = 0,
			BackgroundColor3 = Color3.new(1,1,1),
			BorderColor3 = Color3.new(0,0,0),
			BorderSizePixel = 0,
			Size = UDim2.fromOffset(100, 100)
		},

		ImageButton = {
			Priority = 5,
			BackgroundColor3 = Color3.new(1,1,1),
			BorderColor3 = Color3.new(0,0,0),
			BorderSizePixel = 0,
			Image = "rbxasset://textures/ui/GuiImagePlaceholder.png",
			Size = UDim2.fromOffset(100, 100)
		},

		ImageLabel = {
			Priority = 5,
			BackgroundColor3 = Color3.new(1,1,1),
			BorderColor3 = Color3.new(0,0,0),
			BorderSizePixel = 0,
			Image = "rbxasset://textures/ui/GuiImagePlaceholder.png",
			Size = UDim2.fromOffset(100, 100)
		},

		ScrollingFrame = {
			Priority = 1,
			Active = true,
			BackgroundColor3 = Color3.new(1,1,1),
			BorderColor3 = Color3.new(0,0,0),
			BorderSizePixel = 0,
			ScrollBarImageColor3 = Color3.new(0,0,0),
			Size = UDim2.fromOffset(100, 100)
		},

		TextBox = {
			Priority = 4,
			BackgroundColor3 = Color3.new(1,1,1),
			BorderColor3 = Color3.new(0,0,0),
			BorderSizePixel = 0,
			FontFace = Font.fromEnum(Enum.Font.SourceSans),
			Size = UDim2.fromOffset(200, 50),
			TextColor3 = Color3.new(0,0,0),
			TextSize = 14
		},
		
		TextButton = {
			Priority = 3,
			BackgroundColor3 = Color3.new(1,1,1),
			BorderColor3 = Color3.new(0,0,0),
			BorderSizePixel = 0,
			FontFace = Font.fromEnum(Enum.Font.SourceSans),
			Size = UDim2.fromOffset(200, 50),
			TextColor3 = Color3.new(0,0,0),
			TextSize = 14
		},

		TextLabel = {
			Priority = 2,
			BackgroundColor3 = Color3.new(1,1,1),
			BorderColor3 = Color3.new(0,0,0),
			BorderSizePixel = 0,
			FontFace = Font.fromEnum(Enum.Font.SourceSans),
			Size = UDim2.fromOffset(200, 50),
			TextColor3 = Color3.new(0,0,0),
			TextSize = 14
		},

		UIGridLayout = {
			Priority = 11,
			SortOrder = Enum.SortOrder.LayoutOrder
		},

		UIListLayout = {
			Priority = 10,
			SortOrder = Enum.SortOrder.LayoutOrder
		},

		UIPageLayout = {
			Priority = 12,
			SortOrder = Enum.SortOrder.LayoutOrder
		},

		UITableLayout = {
			Priority = 13,
			SortOrder = Enum.SortOrder.LayoutOrder
		},

		VideoFrame = {
			Priority = 8,
			BackgroundColor3 = Color3.new(1,1,1),
			BorderColor3 = Color3.new(0,0,0),
			BorderSizePixel = 0,
			Size = UDim2.fromOffset(100, 100)
		},

		ViewportFrame = {
			Priority = 7,
			BackgroundColor3 = Color3.new(1,1,1),
			BorderColor3 = Color3.new(0,0,0),
			BorderSizePixel = 0,
			Size = UDim2.fromOffset(100, 100)
		}
	}
}

StylesheetConverter.luau

-- This is temporary until we get a proper way to build stylesheets directly
-- from a file that isn't Luau.

type Rule = {
	Priority: number?,
	Nested: {[string]: Rule}?,
	[string|number]: any
}

type StylesheetDoc = {
	-- rule:
	Name: string,
	DeriveFromBase: boolean,
	Rules: {[string]: Rule}?,
	Tokens: {[string]: any}?
}

local baseSheetModule = require(script.Parent.BaseStyleSheet)::StylesheetDoc
local baseStyleSheet: StyleSheet

local function makeRules(rules: {[string]: Rule}, parent: StyleSheet|StyleRule)
	for selector, rule: Rule in rules do
		local ruleEntry = Instance.new("StyleRule")
		ruleEntry.Archivable = false
		ruleEntry.Name = selector
		ruleEntry.Selector = selector

		if rule.Priority then
			ruleEntry.Priority = rule.Priority
			rule.Priority = nil
		end

		if rule.Nested then
			makeRules(rule.Nested, ruleEntry)
			rule.Nested = nil
		end

		ruleEntry:SetProperties(rule)
		ruleEntry.Parent = parent
	end
end

local function makeStyleSheet(t: StylesheetDoc): StyleSheet
	local sheet = Instance.new("StyleSheet")
	sheet.Archivable = false
	sheet.Name = t.Name

	if t.DeriveFromBase then
		local derive = Instance.new("StyleDerive")
		derive.Archivable = false
		derive.StyleSheet = baseStyleSheet
		derive.Name = "BaseDerive"
		derive.Parent = sheet
	end

	if t.Tokens then
		for tokenName, token in t.Tokens do
			sheet:SetAttribute(tokenName, token)
		end
	end

	if t.Rules then makeRules(t.Rules, sheet) end

	return sheet
end

baseStyleSheet = makeStyleSheet(baseSheetModule)
baseStyleSheet.Parent = script

return makeStyleSheet