roslib/src/actionlib/ActionListener.js

The standard ROS Javascript Library

/**
 * @fileOverview
 * @author Justin Young - justin@oodar.com.au
 * @author Russell Toris - rctoris@wpi.edu
 */

var Topic = require('../core/Topic');
var Message = require('../core/Message');
var EventEmitter2 = require('eventemitter2').EventEmitter2;

/**
 * An actionlib action listener
 *
 * Emits the following events:
 *  * 'status' - the status messages received from the action server
 *  * 'feedback' -  the feedback messages received from the action server
 *  * 'result' - the result returned from the action server
 *
 *  @constructor
 *  @param options - object with following keys:
 *   * ros - the ROSLIB.Ros connection handle
 *   * serverName - the action server name, like /fibonacci
 *   * actionName - the action message name, like 'actionlib_tutorials/FibonacciAction'
 */
function ActionListener(options) {
  var that = this;
  options = options || {};
  this.ros = options.ros;
  this.serverName = options.serverName;
  this.actionName = options.actionName;
  this.timeout = options.timeout;
  this.omitFeedback = options.omitFeedback;
  this.omitStatus = options.omitStatus;
  this.omitResult = options.omitResult;


  // create the topics associated with actionlib
  var goalListener = new Topic({
    ros : this.ros,
    name : this.serverName + '/goal',
    messageType : this.actionName + 'Goal'
  });

  var feedbackListener = new Topic({
    ros : this.ros,
    name : this.serverName + '/feedback',
    messageType : this.actionName + 'Feedback'
  });

  var statusListener = new Topic({
    ros : this.ros,
    name : this.serverName + '/status',
    messageType : 'actionlib_msgs/GoalStatusArray'
  });

  var resultListener = new Topic({
    ros : this.ros,
    name : this.serverName + '/result',
    messageType : this.actionName + 'Result'
  });

  goalListener.subscribe(function(goalMessage) {
      that.emit('goal', goalMessage);
  });

  statusListener.subscribe(function(statusMessage) {
      statusMessage.status_list.forEach(function(status) {
          that.emit('status', status);
      });
  });

  feedbackListener.subscribe(function(feedbackMessage) {
      that.emit('status', feedbackMessage.status);
      that.emit('feedback', feedbackMessage.feedback);
  });

  // subscribe to the result topic
  resultListener.subscribe(function(resultMessage) {
      that.emit('status', resultMessage.status);
      that.emit('result', resultMessage.result);
  });

}

ActionListener.prototype.__proto__ = EventEmitter2.prototype;

module.exports = ActionListener;