Tutorial by Examples

You can use the $q.all function to call a .then method after an array of promises has been successfully resolved and fetch the data they resolved with. Example: JS: $scope.data = [] $q.all([ $http.get("data.json"), $http.get("more-data.json"), ]).then(funct...

The $q constructor function is used to create promises from asynchronous APIs that use callbacks to return results. $q(function(resolve, reject) {...}) The constructor function receives a function that is invoked with two arguments, resolve and reject that are functions which are used to eithe...

We can use $q to defer operations to the future while having a pending promise object at the present, by using $q.defer we create a promise that will either resolve or reject in the future. This method is not equivalent of using the $q constructor, as we use $q.defer to promisify an existing routin...

$q is a built-in service which helps in executing asynchronous functions and using their return values(or exception) when they are finished with processing. $q is integrated with the $rootScope.Scope model observation mechanism, which means faster propagation of resolution or rejection into your m...

If all you need is to wrap the value into a promise, you don't need to use the long syntax like here: //OVERLY VERBOSE var defer; defer = $q.defer(); defer.resolve(['one', 'two']); return defer.promise; In this case you can just write: //BETTER return $q.when(['one', 'two']); $q.when ...

Avoid this Anti-Pattern var myDeferred = $q.defer(); $http(config).then(function(res) { myDeferred.resolve(res); }, function(error) { myDeferred.reject(error); }); return myDeferred.promise; There is no need to manufacture a promise with $q.defer as the $http service alread...