use-state-with-callback

useCombinedReducers React Hook

Custom hook to combine all useReducer hooks for one global state container with one dispatch function. Use at top-level and pass dispatch function (and state) down via React's Context API with Provider and Consumer/useContext.

• Example Application
• "How to implement it"-tutorial.
• Requirements: reducer and useReducer explained.

Installation

npm install use-combined-reducers

Usage

Create a global dispatch function and state object by initializing multiple useReducer hooks in useCombinedReducers:

import React from 'react';
import useCombinedReducers from 'use-combined-reducers';

const App = () => {
  const [state, dispatch] = useCombinedReducers({
    myTodos: React.useReducer(todoReducer, initialTodos),
    myOtherStuff: React.useReducer(stuffReducer, initialStuff),
  });

  const { myTodos, myOtherStuff } = state;

  ...
}

export default App;

You can pass state and dispatch function down via props or React's Context API. Since passing it down with props is straight forward, the approach with context is demonstrated here. In some file:

import React from 'react';

export const StateContext = React.createContext();
export const DispatchContext = React.createContext();

In your top-level React component (or any other component above a component tree which needs managed state):

import React from 'react';
import useCombinedReducers from 'use-combined-reducers';

import { StateContext, DispatchContext } from './somefile.js'; 

const App = () => {
  const [state, dispatch] = useCombinedReducers({
    myTodos: React.useReducer(todoReducer, initialTodos),
    myOtherStuff: React.useReducer(stuffReducer, initialStuff),
  });

  return (
    <DispatchContext.Provider value={dispatch}>
        <StateContext.Provider value={state}>
          <SomeComponent />
        </StateContext.Provider>
    </DispatchContext.Provider>
  );
}

export default App;

In some other component which sits below the state/dispatch providing component:

import React from 'react';

import { StateContext, DispatchContext } from './somefile.js'; 

export default () => {
  const state = React.useContext(StateContext);
  const dispatch = React.useContext(DispatchContext);
  
  const { myTodos, myOtherStuff } = state; 

  return (
    <div>
      ...
    </div>
  );
};

Contribute

• git clone [e-mail]:the-road-to-learn-react/use-combined-reducers.git
• cd use-combined-reducers
• npm install
• npm run test

More

• Publishing a Node Package to NPM
• Node.js Testing Setup