Updating the model property has no effect on the view when updating the model in event callback, any ideas to fix this?

This is my service:

angular.service('Channel', function() {        

    var channel = null; 



    return {        

        init: function(channelId, clientId) {

            var that = this;        



            channel = new goog.appengine.Channel(channelId);

            var socket = channel.open();



            socket.onmessage = function(msg) {

                var args = eval(msg.data);              

                that.publish(args[0], args[1]);

            };

        }       

    };

});

publish() function was added dynamically in the controller.

Controller:

App.Controllers.ParticipantsController = function($xhr, $channel) {

    var self = this;



    self.participants = [];     



    // here publish function is added to service

    mediator.installTo($channel); 



    // subscribe was also added with publish        

    $channel.subscribe('+p', function(name) { 

        self.add(name);     

    });                 



    self.add = function(name) {     

        self.participants.push({ name: name });     

    }

};



App.Controllers.ParticipantsController.$inject = ['$xhr', 'Channel'];

View:

<div ng:controller=App.Controllers.ParticipantsController>      

    <ul>

        <li ng:repeat=participant in participants><label ng:bind=participant.name></label></li>

    </ul>



    <button ng:click=add('test')>add</button>

</div>

So the problem is that clicking the button updates the view properly, but when I get the message from the Channel nothings happens, even the add() function is called