Method send

packages/rtm-api/src/RTMClient.ts:508–539

* Generic method for sending an outgoing message of an arbitrary type. The main difference between this method and * addOutgoingEvent() is that this method does not use a queue so it can only be used while the client is ready * to send messages (in the 'ready' substate of the 'connected' state

(type: string, body = {})

   * @param body the message body
   */
  public send(type: string, body = {}): Promise<number> {
    const message = Object.assign({}, body, {
      type,
      id: this.nextMessageId(),
    });

    return new Promise((resolve, reject) => {
      this.logger.debug(`send() in state: ${this.stateMachine.getStateHierarchy()}`);
      if (this.websocket === undefined) {
        this.logger.error('cannot send message when client is not connected');
        reject(sendWhileDisconnectedError());
      } else if (!(this.stateMachine.getCurrentState() === 'connected' &&
                 this.stateMachine.getStateHierarchy()[1] === 'ready')) {
        this.logger.error('cannot send message when client is not ready');
        reject(sendWhileNotReadyError());
      } else {
        // NOTE: future feature request: middleware pipeline to process the message before its sent
        this.emit('outgoing_message', message);

        const flatMessage = JSON.stringify(message);
        this.logger.debug(`sending message on websocket: ${flatMessage}`);

        this.websocket.send(flatMessage, (error) => {
          if (error !== undefined) {
            this.logger.error(`failed to send message on websocket: ${error.message}`);
            return reject(websocketErrorWithOriginal(error));
          }
          resolve(message.id);
        });
      }
    });
  }

  /**
   * Atomically increments and returns a message ID for the next message.