Files
omnivore/packages/web/lib/hooks/usePersistedState.tsx

67 lines
1.9 KiB
TypeScript

import { useState, useEffect } from 'react'
export function usePersistedState<T>({
key,
initialValue,
isSessionStorage,
defaultEvaluator,
}: {
key: string
initialValue: T
isSessionStorage?: boolean
defaultEvaluator?: () => T
}): [T, (x: T | ((prev: T) => T)) => void, boolean] {
// State to store our value
// Pass initial state function to useState so logic is only executed once
const [isLoading, setIsLoading] = useState(true)
const [storedValue, setStoredValue] = useState(initialValue)
useEffect(() => {
if (typeof window === 'undefined') {
return
}
try {
// Get from local storage by key
const item =
window[isSessionStorage ? 'sessionStorage' : 'localStorage'].getItem(
key
)
// Parse stored json or if none return initialValue
if (item) {
setStoredValue(JSON.parse(item))
} else if (defaultEvaluator) {
setValue(defaultEvaluator())
}
setIsLoading(false)
} catch (error) {
// If error also return initialValue
console.log(error)
}
}, [isSessionStorage, key, setStoredValue])
// Return a wrapped version of useState's setter function that ...
// ... persists the new value to localStorage.
const setValue = (value: T | ((prev: T) => T)): void => {
if (typeof window === 'undefined') {
return
}
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[isSessionStorage ? 'sessionStorage' : 'localStorage'].setItem(
key,
JSON.stringify(valueToStore)
)
} catch (error) {
// A more advanced implementation would handle the error case
console.log(error)
}
}
return [storedValue, setValue, isLoading]
}