Broadcast Changes to Angular Factory Properties

I was making a little website with Angular the other day, and I wanted to have a search box in my nav bar that could be used from any page. When the search control is used, the user is sent to a search page that displays results but also lets users run additional searches. Both search functions use the same angular factory to execute their searches. Unfortunately, I was finding that the nav bar search control wouldn’t update search results when used from the search page.

I was able to solve the problem by using $broadcast and $on. It’s pretty simple, and it looks a lot cleaner than a lot of $watch solutions that I ran into while looking for a solution.

Here’s what my factory looks like:

app.factory('searchService', ['$rootScope', '$http', function ($rootScope, $http) {
    var factory = {
        search: search,
        getResults: getResults
    var _results = [];
    function search(criteria) {
        return $ + 'api/search', criteria).then(function (results) {
            _results =;
            $rootScope.$broadcast('searchCompleted', _results);
            return results;

    function getResults() {
        return _results;

    return factory;

And here’s my searchController that handles the broadcast event with $on:

app.controller('searchController', ['$scope', 'searchService', function ($scope, searchService) {
    $scope.criteria = {};
    $scope.results = searchService.getResults();

    $ = function () {$scope.criteria).then(function (results) {
            $scope.results =;
        }, function (error) {

    $scope.$on('searchCompleted', function (results) {
        $scope.results = searchService.getResults();

Note the use of $rootScope in the factory. Broadcasting the change is a single line of code, and handling the event in relevant controllers is pretty simple, too. Nice!


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