Package Exports

react-hooks-global-state

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Readme

react-hooks-global-state

Simple global state for React with Hooks API

Introduction

This is a library to provide a global state with React Hooks. It has following characteristics.

Optimization for shallow state getter and setter.
- The library cares the state object only one-level deep.
TypeScript type definitions
- A creator function creates hooks with types inferred.
Redux middleware support to some extent
- Some of libraries in Redux ecosystem can be used.
- Redux DevTools Extension could be used in a simple scenario.
Concurrent Mode support (Experimental)
- Undocumented useGlobalStateProvider supports CM without React Context.

Install

npm install react-hooks-global-state

Usage

setState style

import React from 'react';
import { createGlobalState } from 'react-hooks-global-state';

const initialState = { count: 0 };
const { useGlobalState } = createGlobalState(initialState);

const Counter = () => {
  const [count, setCount] = useGlobalState('count');
  return (
    <div>
      <span>Counter: {count}</span>
      {/* update state by passing callback function */}
      <button onClick={() => setCount(v => v + 1)}>+1</button>
      {/* update state by passing new value */}
      <button onClick={() => setCount(count - 1)}>-1</button>
    </div>
  );
};

const App = () => (
  <>
    <Counter />
    <Counter />
  </>
);

reducer style

import React from 'react';
import { createStore } from 'react-hooks-global-state';

const reducer = (state, action) => {
  switch (action.type) {
    case 'increment': return { ...state, count: state.count + 1 };
    case 'decrement': return { ...state, count: state.count - 1 };
    default: return state;
  }
};
const initialState = { count: 0 };
const { dispatch, useGlobalState } = createStore(reducer, initialState);

const Counter = () => {
  const [value] = useGlobalState('count');
  return (
    <div>
      <span>Counter: {value}</span>
      <button onClick={() => dispatch({ type: 'increment' })}>+1</button>
      <button onClick={() => dispatch({ type: 'decrement' })}>-1</button>
    </div>
  );
};

const App = () => (
  <>
    <Counter />
    <Counter />
  </>
);

API

createGlobalState

create a gloal state

It returns a set of functions

useGlobalState: a custom hook works like React.useState
getGlobalState: a function to get a global state by name outside React
setGlobalState: a function to set a global state by name outside React

Parameters

initialState State

Examples

import { createGlobalState } from 'react-hooks-global-state';

const { useGlobalState } = createGlobalState({ count: 0 });

const Component = () => {
  const [count, setCount] = useGlobalState('count');
  ...
};

createStore

create a global store

In additon to useGlobaState which is the same hook as in createGlobalState, a store has getState and dispatch. A store works somewhat similarly to Redux, but not the same.

Parameters

reducer Reducer<State, Action>
initialState State (optional, default (reducer as any)(undefined,{type:undefined}))
enhancer Enhancer<any>?

Examples

import { createStore } from 'react-hooks-global-state';

const initialState = { count: 0 };
const reducer = ...;

const store = createStore(reducer, initialState);
const { useGlobalState } = store;

const Component = () => {
  const [count, setCount] = useGlobalState('count');
  ...
};

Examples

The examples folder contains working examples. You can run one of them with

PORT=8080 npm run examples:01_minimal

and open http://localhost:8080 in your web browser.

You can also try them in codesandbox.io: 01 02 03 04 05 06 07 08 09 10 11 12 13

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