If you're building a web application in angular.js, chances are you will have to send a message between one or more controllers. This is fairly simple to do through the use of services and callbacks. 

var module = angular.module("MyApp", []);

module.service('bridgeService', function(){
    var event;
    
    this.send = function(message){
        event(message);
    };
    
    this.onReceive = function(action){
        event = action;
    };
});

module.controller('FooCtrl', function($scope, bridgeService){
    $scope.sendMessage = function(){
        bridgeService.send($scope.message);
    }
});

module.controller('BarCtrl', function($scope, bridgeService){
    bridgeService.onReceive(function(message) {
        $scope.message = message;
    });
});

this is an overly simple example. You'll probably want to set up an events array so you can subscribe more than one action at a time, but this should be enough to get you started. Here is a jsfiddle example if you need a little more context.