README

Global React State

This package provides simple global state management through React hooks.

No extra files or React components required
No dependencies but React itself
Very small bundle size (< 1 kB)

Usage

Create the global state

import createGlobalState from 'global-react-state';

const [useMyState, setMyState, getMyState] = createGlobalState(initialValue);

Use the global state

const MyComponent = () => {
    const [myState, setMyState] = useMyState();
    
    // ...
};

Set the global state

The setter function can be called inside or outside a React component.

setMyState(newValue);

If the new state is computed using the previous state, you can pass a function to your state setter.

The function will receive the previous value and return an updated value. For example:

setMyState(oldValue => oldValue + 1);

Get the global state

The getter function should only be called outside a React component.

console.log(getMyState());

If you want to get the state inside a React component, you should use useMyState instead.

Best Practice

Export and import

You can easily export the hook or the setter from one file and import it into another:

// myState.ts
export const [useMyState, setMyState] = createGlobalState(initialValue);

import { useMyState } from './myState';

Avoid unnecessary re-render attempts

Because the setter function can also be called outside a component, it is never necessary for a component to use a global state hook without using the value of the state:

// ❌ DON'T do this.

import { useMyState } from './myState';

const MyComponent = () => {
    const [, setMyState] = useMyState();
    
    // Call `setMyState` in here.
};

This will unnecessarily attempt to re-render the component whenever the state updates, since it is using the hook. Instead, you could simply import the setter without the hook:

// ✅ Do this.

import { setMyState } from './myState';

const MyComponent = () => {
    // Call `setMyState` in here.
};

No hook required!

TypeScript Usage

If TypeScript cannot infer your state's type sufficiently, you can explitly define the type using a type parameter on createGlobalState. For example:

const [useNumbers] = createGlobalState<number[]>([]);

Usage no npm install needed!