websocket组件库

源码如下

/**
 * Module dependencies.
 */

import Emitter from "component-emitter";

/**
 * Socket constructor.
 */
class Socket {
  constructor(uri, opts) {
    opts = opts || {};
    this.uri = uri;
    this.readyState = "";
    this.ws = null;
    this.WebSocketImpl = null;
    this.reconnecting = false;
    this.reconnectCounter = 0;
    this.timer = null;
    this.reconnection(opts.reconnection !== false);
    this.reconnectionAttempts(opts.reconnectionAttempts || Infinity);
    this.check();
  }

  check() {
    if ("undefined" !== typeof WebSocket) {
      this.WebSocketImpl = WebSocket;
    } else if (typeof self !== "undefined") {
      this.WebSocketImpl = self.WebSocket || self.MozWebSocket;
    } else {
      throw new Error("Your environment not support WebSocket.");
    }
    this.open();
  }

  open() {
    this.cleanUp();
    if ("closed" === this.readyState || "" === this.readyState) {
      this.doOpen();
    }
  }

  send(packets) {
    if ("open" === this.readyState) {
      this.write(packets);
    } else {
      throw new Error("Transport not open");
    }
  }

  close() {
    if ("opening" === this.readyState || "open" === this.readyState) {
      this.readyState = "closed";
      this.resetReconnectCounter();
      this.doClose();
    }
  }

  write(packets) {
    this.ws.send(packets);
  }

  reconnect() {
    if (this.reconnecting) {
      return;
    }

    const self = this;

    if (this.reconnectCounter >= this._reconnectionAttempts) {
      this.reconnecting = false;
    } else {
      this.reconnectCounter++;
      this.reconnecting = true;
      const delay = 2000;
      this.timer = setTimeout(() => {
        this.reconnecting = false;
        this.open();
      }, delay);
    }
  }

  doOpen() {
    const uri = this.uri;
    this.ws = new this.WebSocketImpl(uri);
    this.addEventListeners();
  }

  doClose() {
    if (typeof this.ws !== "undefined") {
      this.ws.close();
    }
  }

  addEventListeners() {
    const self = this;

    this.ws.onopen = function() {
      self.onOpen();
    };
    this.ws.onclose = function() {
      self.onClose();
    };
    this.ws.onmessage = function(ev) {
      console.log(ev)
      self.onData(ev.data);
    };
    this.ws.onerror = function(e) {
      self.onError("websocket error", e);
    };
  }

  onOpen() {
    this.readyState = "open";
    this.writable = true;
    this.emit("open");
  }

  onClose() {
    this.readyState = "closed";
    this.emit("close");

    if (this._reconnection) {
      this.reconnect();
    }
  }

  onData(packet) {
    const data = this.decodePacket(packet);
    this.onPacket(data);
  }

  onPacket(packet) {
    console.log(packet)
    this.emit("packet", packet);
  }

  onError(msg, desc) {
    let err = new Error(msg);
    err.type = "TransportError";
    err.description = desc;
    this.emit("error", err);
  }

  decodePacket(packet) {
    return packet;
  }

  reconnection(v) {
    this._reconnection = v;
  }

  reconnectionAttempts(v) {
    this._reconnectionAttempts = v;
  }

  resetReconnectCounter() {
    this.reconnectCounter = 0;
  }

  cleanUp() {
    clearTimeout(this.timer);
  }
}

Emitter(Socket.prototype);

export default Socket;