use-global-hook

Easy state management for react using hooks in less than 1kb.

Table of Contents

• Install
• Example
• Complete Examples
• Using TypeScript

Install:

npm i use-global-hook

or

yarn add use-global-hook

Minimal example:

import React from 'react';
import globalHook from 'use-global-hook';

const initialState = {
  counter: 0,
};

const actions = {
  addToCounter: (store, amount) => {
    const newCounterValue = store.state.counter + amount;
    store.setState({ counter: newCounterValue });
  },
};

const useGlobal = globalHook(React, initialState, actions);

const App = () => {
  const [globalState, globalActions] = useGlobal();
  return (
    <div>
      <p>
        counter:
        {globalState.counter}
      </p>
      <button type="button" onClick={() => globalActions.addToCounter(1)}>
        +1 to global
      </button>
    </div>
  );
};

export default App;

Complete examples:

Several counters, one value

Add as many counters as you want, it will all share the same global value. Every time one counter add 1 to the global value, all counters will render. The parent component won't render again.

Asynchronous ajax requests

Search GitHub repos by username. Handle the ajax request asynchronously with async/await. Update the requests counter on every search.

Avoid unnecessary renders

Map a subset of the global state before use it. The component will only re-render if the subset is updated.

Connecting to a class component

Hooks can't be used inside a class component. We can create a Higher-Order Component that connects any class component with the state. With the connect() function, state and actions become props of the component.

Immutable state with Immer.js intagration

Add Immer.js lib on your hook options to manage complex immutable states. Mutate a state draft inside a setState function. Immer will calculate the state diff and create a new immutable state object.

Using TypeScript

Install the TypeScript definitions from DefinitelyTyped

npm install @types/use-global-hook

Example implementation

import globalHook, { Store } from 'use-global-hook';

// Defining your own state and associated actions is required
type MyState = {
  value: string;
};

// Associated actions are what's expected to be returned from globalHook
type MyAssociatedActions = {
  setValue: (value: string) => void;
  otherAction: (other: boolean) => void;
};

// setValue will be returned by globalHook as setValue.bind(null, store)
// This is one reason we have to declare a separate associated actions type
const setValue = (
  store: Store<MyState, MyAssociatedActions>,
  value: string
) => {
  store.setState({ ...store.state, value });
  store.actions.otherAction(true);
};

const otherAction = (
  store: Store<MyState, MyAssociatedActions>,
  other: boolean
) => { /* cool stuff */ };

const initialState: MyState = {
  value: "myString"
};

// actions passed to globalHook do not need to be typed
const actions = {
  setValue,
  otherAction
};

const useGlobal = globalHook<MyState, MyAssociatedActions>(
  React,
  initialState,
  actions
);

// Usage
const [state, actions] = useGlobal<MyState, MyAssociatedActions>();

// Subset
const [value, setValue] = useGlobal<string, (value: string) => void>(
  (state: MyState) => state.value,
  (actions: MyAssociatedActions) => actions.setValue
);

// Without declaring type, useGlobal will return unknown
const [state, actions] = useGlobal(); // returns [unknown, unknown]

// Happy TypeScripting!