Fix EventEmitter global to all Cam objects.

lib/cam.js

@@ -7,7 +7,6 @@
 
 const http = require('http')
 	, crypto = require('crypto')
-	, util = require('util')
 	, events = require('events')
 	, url = require('url')
 	, linerase = require('./utils').linerase
@@ -86,10 +85,64 @@ var Cam = function(options, callback) {
 	setImmediate(function() {
 		this.connect(callback);
 	}.bind(this));
+	this.eventEmitter = new events.EventEmitter();
+	this.eventEmitter.on('newListener', function(name) {
+		// if this is the first listener, start pulling
+		if (name === 'event' && this.eventEmitter.listeners(name).length === 0) {
+			// setImmediate needed because this.eventEmitter.listeners('event').length is used in _eventRequest but
+			// is increased AFTER 'newListener' event is executed
+			setImmediate(this._eventRequest.bind(this));
+		}
+	}.bind(this));
 };
 
 // events.EventEmitter inheritance
-util.inherits(Cam, events.EventEmitter);
+// util.inherits(Cam, events.EventEmitter); // Do not inherit! Because the EventEmitter becomes static (same for all instances of Cam object)
+Cam.prototype.addListener = function(eventName, listener) {
+	return this.eventEmitter.addListener(eventName, listener);
+}
+Cam.prototype.emit = function(event,...data) {
+	return this.eventEmitter.emit(event,...data);
+}
+Cam.prototype.eventNames = function() {
+	return this.eventEmitter.eventNames();
+}
+Cam.prototype.getMaxListeners = function() {
+	return this.eventEmitter.getMaxListeners();
+}
+Cam.prototype.listenerCount = function(eventName) {
+	return this.eventEmitter.listenerCount(eventName);
+}
+Cam.prototype.listeners = function(eventName) {
+	return this.eventEmitter.listeners(eventName);
+}
+Cam.prototype.off = function(eventName, listener) {
+	return this.eventEmitter.off(eventName, listener);
+}
+Cam.prototype.on = function(eventName,listener) {
+	return this.eventEmitter.on(eventName,listener);
+}
+Cam.prototype.once = function(eventName, listener) {
+	return this.eventEmitter.once(eventName, listener);
+}
+Cam.prototype.prependListener = function(eventName, listener) {
+	return this.eventEmitter.prependListener(eventName, listener);
+}
+Cam.prototype.prependOnceListener = function(eventName, listener) {
+	return this.eventEmitter.prependOnceListener(eventName, listener);
+}
+Cam.prototype.removeAllListeners = function(eventName) {
+	return this.eventEmitter.removeAllListeners(eventName);
+}
+Cam.prototype.removeListener = function(eventName, listener) {
+	return this.eventEmitter.removeListener(eventName,listener);
+}
+Cam.prototype.setMaxListeners = function(n) {
+	return this.eventEmitter.setMaxListeners(n);
+}
+Cam.prototype.rawListeners = function(eventName) {
+	return this.eventEmitter.rawListeners(eventName);
+}
 
 /**
  * Connect to the camera and fill device information properties

lib/events.js

@@ -123,8 +123,8 @@ module.exports = function(Cam) {
 			subscriptionId = null;
 		}
 
-		let sendXml = this._envelopeHeader(true)
-		
+		let sendXml = this._envelopeHeader(true);
+
 		if (!subscriptionId) {
 			sendXml += '<a:To>' + urlAddress.href + '</a:To>'
 		} else {
@@ -194,22 +194,22 @@ module.exports = function(Cam) {
 			subscriptionId = null;
 		}
 
-		let sendXml = this._envelopeHeader(true)
-		
+		let sendXml = this._envelopeHeader(true);
+
 		if (!subscriptionId) {
 			sendXml += '<a:To>' + urlAddress.href + '</a:To>'
 		} else {
 			// Axis Cameras use a PullPoint URL and the Subscription ID
 			sendXml += '<a:To mustUnderstand="1">' + urlAddress.href + '</a:To>' +
-					'<SubscriptionId xmlns="http://www.axis.com/2009/event" a:IsReferenceParameter="true">' + this.events.subscription.subscriptionReference.referenceParameters.subscriptionId + '</SubscriptionId>'
+					'<SubscriptionId xmlns="http://www.axis.com/2009/event" a:IsReferenceParameter="true">' + subscriptionId + '</SubscriptionId>'
 		}
 		sendXml += '</s:Header>' +
 			'<s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">' +
 				'<PullMessages xmlns="http://www.onvif.org/ver10/events/wsdl">' +
 					'<Timeout>PT5S</Timeout>' +  // pull timeout must be shorter than Socket timeout or we will get a socket error when there are no new events
 					'<MessageLimit>' + (options.messageLimit || 10) + '</MessageLimit>' +
 				'</PullMessages>' +
-			this._envelopeFooter()
+			this._envelopeFooter();
 		this._request({
 			url: urlAddress,
 			body: sendXml
@@ -241,14 +241,14 @@ module.exports = function(Cam) {
 			subscriptionId = null;
 		}
 
-		let sendXml = this._envelopeHeader(true)
-		
+		let sendXml = this._envelopeHeader(true);
+
 		if (!subscriptionId) {
 			sendXml += '<a:To>' + urlAddress.href + '</a:To>'
 		} else {
 			// Axis Cameras use a PullPoint URL and the Subscription ID
 			sendXml += '<a:To mustUnderstand="1">' + urlAddress.href + '</a:To>' +
-					'<SubscriptionId xmlns="http://www.axis.com/2009/event" a:IsReferenceParameter="true">' + this.events.subscription.subscriptionReference.referenceParameters.subscriptionId + '</SubscriptionId>'
+					'<SubscriptionId xmlns="http://www.axis.com/2009/event" a:IsReferenceParameter="true">' + subscriptionId + '</SubscriptionId>'
 		}
 		sendXml += '</s:Header>' +
 			'<s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">' +
@@ -259,14 +259,15 @@ module.exports = function(Cam) {
 			body: sendXml
 		}, function(err, res, xml) {
 			if (!err) {
+				this.eventEmitter.removeAllListeners('event'); // We can subscribe again only if there is no 'event' listener
 				var data = linerase(res).unsubscribeResponse;
 			}
 			if (callback) {
 				callback.call(this, err, data, xml);
 			}
 		}.bind(this));
 	};
-	
+
 	/**
 	 * Count time before pull-point subscription terminates
 	 * @param {Cam~CreatePullPointSubscriptionResponse} response
@@ -277,28 +278,24 @@ module.exports = function(Cam) {
 		return new Date(Date.now() - response.currentTime.getTime() + response.terminationTime.getTime());
 	}
 
-	/**
-	 * Bind event handling to the `event` event
-	 */
-	Cam.prototype.on('newListener', function(name) {
-		// if this is the first listener, start pulling
-		if (name === 'event' && this.listeners(name).length === 0) {
-			this._eventRequest();
-		}
-	});
-
 	/**
 	 * Event loop for pullMessages request
 	 * @private
 	 */
 	Cam.prototype._eventRequest = function() {
-		this.events.timeout = this.events.timeout || 30000; // setting timeout
-		this.events.messageLimit = this.events.messageLimit || 10; // setting message limit
-		if (!this.events.terminationTime || (this.events.terminationTime < Date.now() + this.events.timeout)) {
-			// if there is no pull-point subscription or it will be dead soon, create new
-			this.createPullPointSubscription(this._eventPull.bind(this));
+		if (this.eventEmitter.listeners('event').length) { // check for event listeners, if zero, stop pulling
+			this.events.timeout = this.events.timeout || 30000; // setting timeout
+			this.events.messageLimit = this.events.messageLimit || 10; // setting message limit
+			if (!this.events.terminationTime || (this.events.terminationTime < Date.now() + this.events.timeout)) {
+				// if there is no pull-point subscription or it will be dead soon, create new
+				this.createPullPointSubscription(this._eventPull.bind(this));
+			} else {
+				this._eventPull();
+			}
 		} else {
-			this._eventPull();
+			delete this.events.terminationTime;
+
+			this.unsubscribe();
 		}
 	};
 
@@ -307,7 +304,7 @@ module.exports = function(Cam) {
 	 * @private
 	 */
 	Cam.prototype._eventPull = function() {
-		if (this.listeners('event').length) { // check for event listeners, if zero, stop pulling
+		if (this.eventEmitter.listeners('event').length) { // check for event listeners, if zero, stop pulling
 			this.pullMessages({
 				messageLimit: this.events.messageLimit
 			}, function(err, data, xml) {

test/common.coffee

@@ -320,3 +320,96 @@ describe 'Common functions', () ->
         assert.equal err, null
         assert.equal typeof data, 'string'
         done()
+
+  describe 'EventEmitter', () ->
+    onEvent = null
+    eventNbr = 0
+    it 'should listen with `addListener`', (done) ->
+      cam.removeAllListeners() # Remove all listeners in case some remains
+      eventNbr = 0
+      onEvent = (msg) ->
+        eventNbr += 1
+      cam.addListener 'myEvent', onEvent
+      listeners = cam.listeners 'myEvent'
+      assert.equal listeners.length, 1
+      listenerCount = cam.listenerCount 'myEvent'
+      assert.equal listenerCount, 1
+      setTimeout () ->
+        cam.emit 'myEvent', ''
+      , 250
+      setTimeout () ->
+        assert.ok eventNbr > 0
+        done()
+      , 1000
+    it 'should stop listening with `removeListener`', (done) ->
+      eventNbr = 0
+      cam.removeListener 'myEvent', onEvent
+      listeners = cam.listeners 'myEvent'
+      assert.equal listeners.length, 0
+      listenerCount = cam.listenerCount 'myEvent'
+      assert.equal listenerCount, 0
+      setTimeout () ->
+        cam.emit 'myEvent', ''
+      , 250
+      setTimeout () ->
+        assert.ok eventNbr == 0
+        done()
+      , 500
+    it 'should listen with `on`', (done) ->
+      cam.removeAllListeners() # Remove all listeners in case some remains
+      eventNbr = 0
+      onEvent = (msg) ->
+        eventNbr += 1
+      cam.on 'myEvent', onEvent
+      listeners = cam.listeners 'myEvent'
+      assert.equal listeners.length, 1
+      listenerCount = cam.listenerCount 'myEvent'
+      assert.equal listenerCount, 1
+      setTimeout () ->
+        cam.emit 'myEvent', ''
+      , 250
+      setTimeout () ->
+        assert.ok eventNbr > 0
+        done()
+      , 500
+    # it 'should stop listening with `off`', (done) ->
+    #   eventNbr = 0
+    #   cam.off 'myEvent', onEvent
+    #   # cam.removeListener 'myEvent', onEvent
+    #   listeners = cam.listeners 'myEvent'
+    #   assert.equal listeners.length, 0
+    #   listenerCount = cam.listenerCount 'myEvent'
+    #   assert.equal listenerCount, 0
+    #   setTimeout () ->
+    #     cam.emit 'myEvent', ''
+    #   , 250
+    #   setTimeout () ->
+    #     assert.ok eventNbr == 0
+    #     done()
+    #   , 500
+    it 'should listen only once with `once`', (done) ->
+      cam.removeAllListeners('myEvent') # Remove all listeners in case some remains
+      setTimeout () ->
+        eventNbr = 0
+        onEvent = (msg) ->
+          eventNbr += 1
+        cam.once 'myEvent', onEvent
+        listeners = cam.listeners 'myEvent'
+        assert.equal listeners.length, 1
+        listenerCount = cam.listenerCount 'myEvent'
+        assert.equal listenerCount, 1
+        emit = () ->
+          cam.emit('myEvent', '')
+        setTimeout () ->
+          setImmediate emit # Send twice
+          setImmediate emit
+        , 100
+        setTimeout () ->
+          assert.ok eventNbr == 1
+          listeners = cam.listeners 'myEvent'
+          assert.equal listeners.length, 0
+          listenerCount = cam.listenerCount 'myEvent'
+          assert.equal listenerCount, 0
+          done()
+        , 500
+      , 100