WebSocket协议-Socket.io 服务端API

服务端API

使用express+http创建server：

var app = require('express')() //初始化express，app作为HTTP服务器的回调函数
var http = require('http').Server(app)
var io = require('socket.io')(http) //传入http对象初始化socket.io的实例

IO

io.sockets

• (Namespace)
  命名空间默认为/

amespace {
  name: '/',
  server:
   Server {
     nsps: { '/': [Circular] },
     parentNsps: Map {},
     _path: '/socket.io',
     _serveClient: true,
     parser:
      { protocol: 4,
        types: [Array],
        CONNECT: 0,
        DISCONNECT: 1,
        EVENT: 2,
        ACK: 3,
        ERROR: 4,
        BINARY_EVENT: 5,
        BINARY_ACK: 6,
        Encoder: [Function: Encoder],
        Decoder: [Function: Decoder] },
     encoder: Encoder {},
     _adapter: [Function: Adapter],
     _origins: '*:*',
     sockets: [Circular],
     eio:
      Server {
        clients: {},
        clientsCount: 0,
        wsEngine: 'ws',
        pingTimeout: 5000,
        pingInterval: 25000,
        upgradeTimeout: 10000,
        maxHttpBufferSize: 100000000,
        transports: [Array],
        allowUpgrades: true,
        allowRequest: [Function: bound ],
        cookie: 'io',
        cookiePath: '/',
        cookieHttpOnly: true,
        perMessageDeflate: [Object],
        httpCompression: [Object],
        initialPacket: [Array],
        ws: [Object],
        _events: [Object],
        _eventsCount: 1 },
     httpServer:
      Server {
        domain: null,
        _events: [Object],
        _eventsCount: 5,
        _maxListeners: undefined,
        _connections: 0,
        _handle: null,
        _usingSlaves: false,
        _slaves: [],
        _unref: false,
        allowHalfOpen: true,
        pauseOnConnect: false,
        httpAllowHalfOpen: false,
        timeout: 120000,
        keepAliveTimeout: 5000,
        _pendingResponseData: 0,
        maxHeadersCount: null,
        [Symbol(asyncId)]: -1 },
     engine:
      Server {
        clients: {},
        clientsCount: 0,
        wsEngine: 'ws',
        pingTimeout: 5000,
        pingInterval: 25000,
        upgradeTimeout: 10000,
        maxHttpBufferSize: 100000000,
        transports: [Array],
        allowUpgrades: true,
        allowRequest: [Function: bound ],
        cookie: 'io',
        cookiePath: '/',
        cookieHttpOnly: true,
        perMessageDeflate: [Object],
        httpCompression: [Object],
        initialPacket: [Array],
        ws: [Object],
        _events: [Object],
        _eventsCount: 1 } },
  sockets: {},
  connected: {},
  fns: [],
  ids: 0,
  rooms: [],
  flags: {},
  adapter: Adapter { nsp: [Circular], rooms: {}, sids: {}, encoder: Encoder {} } }

常用的API如下：

io.on('connection',  (socket) => {
  // 发送给当前客户端
  socket.emit('hello', 'can you hear me?', 1, 2, 'abc');

  // 发送给所有客户端，除了发送者
  socket.broadcast.emit('broadcast', 'hello friends!');

  // 发送给同在 'game' 房间的所有客户端，除了发送者
  socket.to('game').emit('nice game', "let's play a game");

  // 发送给同在 'game1' 或 'game2' 房间的所有客户端，除了发送者
  socket.to('game1').to('game2').emit('nice game', "let's play a game (too)");

  //发送给在线的所有客户端
  io.emit('new message',  'an event sent to all connected clients'); 
  
  // 发送给同在 'game' 房间的所有客户端，包括发送者
  io.in('game').emit('big-announcement', 'the game will start soon');

  // 发送给同在 'myNamespace' 命名空间下的所有客户端，包括发送者
  io.of('myNamespace').emit('bigger-announcement', 'the tournament will start soon');

  // 发送给指定 socketid 的客户端（私密消息）
  socket.to().emit('hey', 'I just met you');

  // 包含回执的消息
  socket.emit('question', 'do you think so?', function (answer) {});

  // 不压缩，直接发送，默认压缩
  socket.compress(false).emit('uncompressed', "that's rough");

  // 发送给当前 node 实例下的所有客户端（在使用多个 node 实例的情况下）
  io.local.emit('hi', 'my lovely babies');
};

看完API，下一篇来看一个聊天室demo