Created
May 14, 2020 13:30
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import { useState, useCallback } from "react"; | |
export default function usePersistedState(key, initialValue) { | |
// State to store our value | |
// Pass initial state function to useState so logic is only executed once | |
const [storedValue, setStoredValue] = useState(() => { | |
try { | |
// Get from local storage by key | |
const item = window.localStorage.getItem(key); | |
// Parse stored json or if none return initialValue | |
return item ? JSON.parse(item) : initialValue; | |
} catch (error) { | |
// If error also return initialValue | |
console.log(error); | |
return initialValue; | |
} | |
}); | |
// Return a wrapped version of useState's setter function that ... | |
// ... persists the new value to localStorage. | |
const setValue = useCallback( | |
value => { | |
try { | |
// Allow value to be a function so we have same API as useState | |
const valueToStore = | |
value instanceof Function ? value(storedValue) : value; | |
// Save state | |
setStoredValue(valueToStore); | |
// Save to local storage | |
window.localStorage.setItem(key, JSON.stringify(valueToStore)); | |
} catch (error) { | |
// A more advanced implementation would handle the error case | |
console.log(error); | |
} | |
}, | |
[key, storedValue] | |
); | |
return [storedValue, setValue]; | |
} |
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