Angular $rootScope.Scope.$once

$once.js

/**
 * Angular $rootScope.Scope.$once
 * Copyright (c) 2014 marlun78
 * MIT License, https://gist.github.com/marlun78/bd0800cf5e8053ba9f83
 */
$provide.decorator('$rootScope', function ($delegate) {
    var Scope = Object.create($delegate).constructor;
    Scope.prototype.$once = function (name, listener) {
        var deregister = this.$on(name, function () {
            deregister();
            listener.apply(this, arguments);
        });
        return deregister;
    };
    return $delegate;
});