Simulate db operation in angularJs?

Question

I want to simulate an async db operation in AngularJs. ( via setTimeout ).

I have this factory function code :( jsbin ) which uses an internal array :

 shoppingModule.factory('Items', function() {
        var items = {};
        items.query = function() {
          // In real apps, we'd pull this data from the server...
          return [
            {title: 'Paint pots', description: 'Pots full of paint', price: 3.95},
            {title: 'Polka dots', description: 'Dots with polka', price: 2.95},
            {title: 'Pebbles', description: 'Just little rocks', price: 6.95}
          ];
        };
        return items;
      });

The controller , in turn calls :

 function ShoppingController($scope, Items) {
        $scope.items = Items.query();
      }

But I want to simulate the return of data as async operation via setTimeout operation. ( in short - I want to add non-blocking delay)

what have I tried ?

I tried to use $timeout variable without any success., also tried to use setTimeout without success (cuz I didnt had $scope object inside the method.)

Question :

how can I add setTimeout( 3 sec to simulate db operation) into the factory function ?

Answer 1

You can achieve this using promises. Modify your code to use something like this:

Factory:

var deferred = $q.defer();
$timeout(function () {
    var returnObj = [
            {title: 'Paint pots', description: 'Pots full of paint', price: 3.95},
            {title: 'Polka dots', description: 'Dots with polka', price: 2.95},
            {title: 'Pebbles', description: 'Just little rocks', price: 6.95}
    ];
    deferred.resolve(returnObj);
}, 3000);

return deferred.promise;

And then just call it like this from the controller:

$scope.items = Items.query().then(function(res){
    alert(res);
    // successfully resolved
}, function(err) {
    // handle errors
});