Skip to content

Instantly share code, notes, and snippets.

@AngelAlexQC
Created August 9, 2022 17:13
Show Gist options
  • Star 0 You must be signed in to star a gist
  • Fork 0 You must be signed in to fork a gist
  • Save AngelAlexQC/65c31d446dd7c140083d4f1b8dbe7c99 to your computer and use it in GitHub Desktop.
Save AngelAlexQC/65c31d446dd7c140083d4f1b8dbe7c99 to your computer and use it in GitHub Desktop.
Use global state with localStorage, sync between tabs
import { useEffect, useState } from "react";
const useLocalStorage = (key, initialValue) => {
// State to store our value
// Pass initial state function to useState so logic is only executed once
const [storedValue, setStoredValue] = useState(() => {
if (typeof window === "undefined") {
return initialValue;
}
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 = (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
if (typeof window !== "undefined") {
window.localStorage.setItem(key, JSON.stringify(valueToStore));
}
} catch (error) {
// A more advanced implementation would handle the error case
console.log(error);
}
};
// Sync localStorage between tabs
useEffect(() => {
const listener = (e) => {
if (e.key === key) {
setStoredValue(JSON.parse(e.newValue));
}
};
window.addEventListener("storage", listener);
return () => {
window.removeEventListener("storage", listener);
};
}
, [
key,
initialValue,
]);
return [storedValue, setValue];
};
export default useLocalStorage;
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment