Wednesday 3 October 2018

react socket.io


package.json

{
  "name": "react-socketio",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "concurrently": "^4.0.1",
    "react": "^16.5.2",
    "react-dom": "^16.5.2",
    "react-scripts": "1.1.5",
    "socket.io-client": "^2.1.1"
  },
  "scripts": {
    "start": "concurrently --kill-others \"node server/server.js\" \"react-scripts start\"",
    "build": "react-scripts build",
    "test": "react-scripts test --env=jsdom",
    "eject": "react-scripts eject"
  },
  "devDependencies": {}
}

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server/package.json

{
  "name": "server",
  "version": "1.0.0",
  "description": "",
  "main": "server.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "node server.js"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "express": "^4.16.3",
    "socket.io": "^2.1.1"
  }
}

----------------------------------------

server.js

const express = require('express');
const socket = require('socket.io');

const app = express();

//server entry port
const port = 5000;

server = app.listen(port, function(){
    console.log('server is running on port ', port)
});

let clientNum = 0;

io = socket(server);

io.on('connection', (socket) => {
    
    clientNum++;
    let currentTime = new Date();
    const socketId = socket.id;

    const connectionRes = currentTime.toLocaleString() + ' ' + 
      socketId + ' connected. ' +clientNum.toString() + ' online'; 

    console.log(connectionRes);

    //send to self when connected
    io.to(socketId).emit('server_connect', connectionRes);

    //response to client send event
    socket.on('client_chat', data=>{
        currentTime = new Date();

        //send to all clients
        //io.emit('server', 'server response');

        //send to everyone except self
        socket.broadcast.emit('server_chat', 
          {
            name: data.name==''? socketId.toString() : data.name,
            message: data.message,
          });

    })

    //client leaves 
    socket.on('disconnect', () => {
      clientNum--;
      currentTime = new Date();

      console.log(currentTime.toLocaleString(), 
        'client disconnected. users', clientNum);
    })

});

---------------------------------------

app.js

import React, { Component } from 'react';
import './App.css';
import io from 'socket.io-client'

class App extends Component {
  constructor(props) {
    super(props)
    
    this.state={
      connectionStatus: '',
      chat: [],
      name: '',
      message: '',
    }

    //connect to server
    this.socket = io('localhost:5000')

    this.socket.on('server_connect', data=>{
      this.setState({connectionStatus: data});
    });

    //append received message to chat
    this.socket.on('server_chat', data=>{
      this.setState(prev=>
        {
          const newChat = <div>
            <span style={{color: 'blue'}}>{data.name}</span>
            <span>: {data.message}</span>
          </div>

          return {
            chat: [...prev.chat].concat(newChat),
          }
      });
    });
  }

  send=()=>{ 

    this.socket.emit('client_chat', {
      name: this.state.name,
      message: this.state.message,
    });

    //append my message to chat
    this.setState(prev=>
      {
        const newChat = <div>
          <span style={{color: 'green'}}>me</span>
          <span>: {this.state.message}</span>
        </div>

        return {
          chat: [...prev.chat].concat(newChat),
        }
    });
  }

  changeName=(e)=>{
    this.setState({name: e.target.value});
  }

  changeMessage=(e)=>{
    this.setState({message: e.target.value});
  }

  componentDidMount(){
    console.log(JSON.stringify(process.env));
  }

  render() {

    const chatDialog = this.state.chat.map((item,index)=>{
      return <div key={index}>{item}</div>
    })

    return (
      <div>
        {this.state.connectionStatus} <br/>

        <div style={{height:'300px',
                 backgroundColor:'lightGrey',
                 overflow:'scroll'}}>
          {chatDialog}
        </div>

        <input placeholder='Name'
          onChange={(e)=>this.changeName(e)}></input>
        <br/>
        <textarea style={{width:'350px', height:'100px'}} placeholder='Message'
          onChange={(e)=>this.changeMessage(e)}></textarea>
        <br/>
        <button onClick={()=>this.send()}>send</button>
      </div>
    );
  }
}

export default App;

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