Intelligent 'Allow' header field value.

Do not set a method in the 'Allow' header field if its corresponding event is not defined or has zero listeners.

Author: jmillan

src/Registrator.js

@@ -57,7 +57,7 @@ JsSIP.Registrator.prototype = {
         'cseq': (this.cseq += 1)
       }, [
         'Contact: '+ this.contact + ';expires=' + this.expires,
-        'Allow: '+ JsSIP.c.ALLOWED_METHODS
+        'Allow: '+ JsSIP.utils.getAllowedMethods(this.ua)
       ]);
 
     request_sender = new JsSIP.RequestSender(this, this.ua);

src/Session.js

@@ -134,7 +134,7 @@ JsSIP.Session.prototype.connect = function(target, options) {
   }
 
   extraHeaders.push('Contact: <'+ this.contact + ';ob>');
-  extraHeaders.push('Allow: '+ JsSIP.c.ALLOWED_METHODS);
+  extraHeaders.push('Allow: '+ JsSIP.utils.getAllowedMethods(this.ua));
   extraHeaders.push('Content-Type: application/sdp');
 
   request = new JsSIP.OutgoingRequest(JsSIP.c.INVITE, target, this.ua, requestParams, extraHeaders);

src/UA.js

@@ -361,7 +361,7 @@ JsSIP.UA.prototype.receiveRequest = function(request) {
    */
   if(method === JsSIP.c.OPTIONS) {
     request.reply(200, JsSIP.c.REASON_200, [
-      'Allow: '+ JsSIP.c.ALLOWED_METHODS,
+      'Allow: '+ JsSIP.utils.getAllowedMethods(this),
       'Accept: '+ JsSIP.c.ACCEPTED_BODY_TYPES
     ]);
   }

src/constants.js

@@ -198,5 +198,11 @@ JsSIP.c = {
   ALLOWED_METHODS: 'INVITE, ACK, CANCEL, BYE, OPTIONS, MESSAGE, SUBSCRIBE',
   SUPPORTED: 'path, outbound, gruu',
   ACCEPTED_BODY_TYPES: 'application/sdp',
-  TAG_LENGTH: 10
+  TAG_LENGTH: 10,
+
+  // User Agent EVENT METHODS
+  UA_EVENT_METHODS: {
+    'newSession': 'INVITE',
+    'newMessage': 'MESSAGE'
+  }
 };

src/utils.js

@@ -129,6 +129,19 @@ JsSIP.utils = {
     }
   },
 
+  getAllowedMethods: function(ua) {
+    var event,
+      allowed = JsSIP.c.ALLOWED_METHODS.split(', ');
+
+    for (event in JsSIP.c.UA_EVENT_METHODS) {
+      if (!ua.checkEvent(event) || ua.listeners(event).length === 0) {
+        allowed.splice(allowed.indexOf(JsSIP.c.UA_EVENT_METHODS[event]), 1);
+      }
+    }
+
+    return allowed.join(', ');
+  },
+
   // MD5 (Message-Digest Algorithm) http://www.webtoolkit.info
   MD5: function(string) {
     function RotateLeft(lValue, iShiftBits) {