A useLocalStorage React Hook for JavaScript and Typescript
Nick Scialli
January 10, 2021
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I have created and open-sourced a useLocalStorage hook I use under the npm module name, uselocalstorage. This article will go into how to install and use the hook.
The Repo
Please help me grow this hook by starring the repo here: uselocalstorage Github Repo. Additionally, I would appreciate any contributions/enhancements you might have!
Installating uselocalstorage
You can install the package with npm:
npm i use-local-storage
Or with yarn:
yarn add use-local-storage
Basic Usage
In its most basic form, the useLocalStorage
hook just needs the Local Storage key
you wish to use. However, itβs advised that you also provde a default value as a second argument in the event that they key
does not yet exist in Local Storage.
The following usage will persist the username
variable in a "name"
key in Local Storage. It will have a default/initial value of an empty string ""
. This default value witll only be used if there is no value already in Local Storage.
import useLocalStorage from 'use-local-storage';
function MyComponent() {
const [username, setUsername] = useLocalStorage('name', '');
return (
<>
<input
value={username}
onChange={(e) => {
setUsername(e.target.value);
}}
/>
</>
);
}
Note: By default, the useLocalStorage
hook uses JSON.stringify
and JSON.parse
to serialize and parse the data, respectively. A custom serializer and/or parser can be configured if desired (discussed below in the Advanced Usage section).
Typescript Use
The type of username
will be inferred from your default value. In this case, the type of string
will be inferred.
If you use useLocalStorage
without providing a default value, or you simply want to specify that username
is actually of a different type, you should pass the type of your data as a generic:
import useLocalStorage from 'use-local-storage';
function MyComponent() {
const [username, setUsername] = useLocalStorage<string>('name');
return (
<>
<input
value={username}
onChange={(e) => {
setUsername(e.target.value);
}}
/>
</>
);
}
Advanced Usage / Options
the useLocalStorage
hook takes an optional third options
argument. This allows you to configure a custom serializer and/or parser if you need to use something other than JSON.stringify
and JSON.parse
. The options
object also has a logger
key to log an errors caught in the hook.
const options = {
serializer: (obj) => {
/* Serialize logic */
return someString;
},
parser: (str) => {
/* Parse logic */
return parsedObject;
},
logger: (error) => {
// Do some logging
},
};
const [data, setData] = useLocalStorage('data', { foo: 'bar' }, options);
Attribution
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Sign up for the newsletter Β»Nick Scialli is a senior UI engineer at Microsoft.