use-emitter

React helper for event emitters and socket.io

Installation

npm install use-emitter

yarn add use-emitter

Usage

EmitterProvider

// App.jsx
import React from 'react';

import { EmitterProvider } from 'use-emitter';

// import some kind of event emitter
import EventEmitter from 'events';
const myEmitter = new EventEmitter();

// you can also use socket.io as event emitter
import io from 'socket.io-client';
const myEmitter = io('http://some-socket-server.com');


export default function () {
   return (
      <EmitterProvider emitter={myEmitter}>{...children}</EmitterProvider>
   );
};

useEvent

Use data and the emit function for the specific event.

import React from 'react';

import { useEvent } from 'use-emitter';

export default function SomeComponent () {
   const [ message, emitMessage ] = useEvent('new-message');
   const firstMessage = useEvent.once('new-message');

   return (
         <div>
            <p>Current message: {message}</p>
            <p>First message: {firstMessage}</p>
         </div>

         <input
            type="text"
            value={message}
            onChange={e => emitMessage(e.target.value)}
         />
      </div>
   );
};

You can also provide the default value of the event as the second parameter of the useEvent function.

const message = useEvent('new-message', 'Message has not been set yet');
const firstMessage = useEvent.once('new-message', 'Message has not been set yet');

useEmit

Use only emit function for the specific event.

import React, { useState } from 'react';

import { useEmit } from 'use-emitter';

export default function SomeComponent () {
   const [ messageText, setMessageText ] = useState('');
   const emitMessage = useEmit('message');

   return (
      <div>
         <input
            type="text"
            value={messageText}
            onChange={e => updateMessageText(e.target.value)}
         />

         <button onClick={() => emitMessage(messageText)}>
            Set message
         </button>
      </div>
   );
}

useEmitter

Use the full instance of the emitter with all of its methods.

import { useEmitter } from 'use-emitter';

export default function SomeComponent () {
   const emitter = useEmitter();
}

Additional properties

Additional properties for the on method. If the event emitter of your choice expects additional options, you can provide them after the default value.

import { useEvent } from 'use-emitter';

export default function SomeComponent () {
   const [data, emitData] = useEvent('event-name', null, arg1, arg2, arg3);
}

// Event emitter will receive the next arguments:
// emitter.on('event-name', callback(), arg1, arg2, arg3)

Additional properties for the emit method. If the event emitter of your choice expects additional options or multiple data values, you can provide them as the arguments of the emit function.

import { useEvent } from 'use-emitter';

export default function SomeComponent () {
   const [data, emitData] = useEvent('event-name');

   function handleClick () {
      emitData(data, arg1, arg2, arg3)
   }
}

// Event emitter will receive the next arguments:
// emitter.emit('event-name', data, arg1, arg2, arg3)