40 lines
1.2 KiB
JavaScript
40 lines
1.2 KiB
JavaScript
import { useState, useEffect, useRef } from 'react'
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// See: https://usehooks.com/useLocalStorage/
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function useLocalStorage(key, initialValue) {
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const prefix = 'fs_'
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const [storedValue, setStoredValue] = useState(initialValue);
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// use this to track whether it's mounted. useful for doing other effects outside this hook
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const [ready, setReady] = useState(false);
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const readyInternal = useRef(false);
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const setValue = function (value) {
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if (!readyInternal.current) {
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return null
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}
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try {
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const valueToStore = value instanceof Function ? value(storedValue) : value
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setStoredValue(valueToStore)
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window.localStorage.setItem(prefix + key, JSON.stringify(valueToStore))
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} catch (error) {
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console.log(error)
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}
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}
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// get the item from localstorage after the component has mounted. empty brackets mean it runs one time
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useEffect(() => {
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readyInternal.current = true;
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const item = window.localStorage.getItem(prefix + key)
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if (item) {
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setValue(JSON.parse(item));
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} else if (storedValue) {
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setValue(storedValue)
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}
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setReady(true);
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}, [])
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return [storedValue, setValue, ready]
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}
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export default useLocalStorage
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