CODEWITHSUNDEEP
javascriptangularjsasynchronous
redrom
redrom

Reputation: 11642

AngularJS : How to execute function in pre-defined order?

I have following receiver in my AngularJS Controller:

   // Receive broadcast
        $rootScope.$on('setPlayListEvent', function(event, playListData) {
          if($scope.someSoundsArePlaying === true) {
             $scope.stopAllSelectedSounds();
          }
            $scope.setPlaylistToView(playListData);
        });

But it seems, that method called setPlaylistToView is always called and executed before the code:

 if($scope.someSoundsArePlaying === true) {
                 $scope.stopAllSelectedSounds();
              }

And so it can affect the result of the method.

I would like to ask, how can i set " execution order" of functions? Something like resolve..then..

Thanks for any advice.

Upvotes: 0

Views: 94

Answers (1)

Or Guz
Or Guz

Reputation: 1018

Javascript is single threaded so you don't want to hold the thread, therefor a possible way to handle your issue is using a promise.

I would have write the code in the following way:

function stopAllSelectedSounds() {
  var deferred = $q.defer();

  //Perform logic

  //if logic performed successfuly
  deferred.resolve();

  //if logic failed
  deferred.reject('reason is blah');

  return deferred.promise;
}

$scope.stopAllSelectedSounds().then(function() {
  alert('Success');
  $scope.setPlaylistToView(playListData);
}, function(reason) {
  alert('Failed ' + reason);
});

This way only when stopAllSelectedSounds is successfully executed you will execute setPlaylistToView without halting the entire app.

see - Angular's Q documentation

A service that helps you run functions asynchronously, and use their return values (or exceptions) when they are done processing.

Upvotes: 1

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