Method onOpen

packages/engine.io/lib/socket.ts:116–145

* Called upon transport considered open. * * @private

()

   * @private
   */
  private onOpen() {
    this.readyState = "open";

    // sends an `open` packet
    this.transport.sid = this.id;
    this.sendPacket(
      "open",
      JSON.stringify({
        sid: this.id,
        upgrades: this.getAvailableUpgrades(),
        pingInterval: this.server.opts.pingInterval,
        pingTimeout: this.server.opts.pingTimeout,
        maxPayload: this.server.opts.maxHttpBufferSize,
      }),
    );

    if (this.server.opts.initialPacket) {
      this.sendPacket("message", this.server.opts.initialPacket);
    }

    this.emit("open");

    if (this.protocol === 3) {
      // in protocol v3, the client sends a ping, and the server answers with a pong
      this.resetPingTimeout();
    } else {
      // in protocol v4, the server sends a ping, and the client answers with a pong
      this.schedulePing();
    }
  }

  /**
   * Called upon transport packet.