AngularJS Promises, $q, defer

by

IMHO I think there’s a much clever (and elegant) way to do this with $q.all.

Please take a look at the code below.

I am assuming that you want to return the data at once with all the results aggregated on a big array.

var myApp = angular.module('myApp', []);

myApp.factory('myService', function ($http, $q) {
    return {
        getAllData: function () {
            return $q.all([
                $http.get('../wordpress/api/core/get_category_posts/?category_id=14'),
                $http.get('../wordpress/api/core/get_category_posts/?category_id=15'),
                $http.get('../wordpress/api/core/get_category_posts/?category_id=16'),
                $http.get('../wordpress/api/core/get_category_posts/?category_id=17')
            ]).then(function (results) {
                var aggregatedData = [];
                angular.forEach(results, function (result) {
                    aggregatedData = aggregatedData.concat(result.data);
                });
                return aggregatedData;
            });
        }
    };
});

You can see above that the aggregatedData is only generated once all the async calls are completed via the $q.all.

You just need to include the service as dependency into one of your controllers, for example, and call the service like this myService.getAllData()

Let me know if you need a full working example and I can provide one! 🙂

More Related Contents:

  1. What’s the difference between returning value or Promise.resolve from then()
  2. Produce a promise which depends on recursive promises
  3. What is the explicit promise construction antipattern and how do I avoid it?
  4. Aren’t promises just callbacks?
  5. How to access the value of a promise?
  6. Resolve promises one after another (i.e. in sequence)?
  7. Issue in returning data retrieved from DB queries called in the loop
  8. Caching a promise object in AngularJS service
  9. Does never resolved promise cause memory leak?
  10. How to sequentially run promises with Q in Javascript?
  11. return value after a promise [duplicate]
  12. Break promise chain and call a function based on the step in the chain where it is broken (rejected)
  13. Why is ‘this’ undefined inside class method when using promises? [duplicate]
  14. multiple, sequential fetch() Promise
  15. How do I tell if an object is a Promise?
  16. How to check if an object is a Promise?
  17. Are there still reasons to use promise libraries like Q or BlueBird now that we have ES6 promises? [closed]
  18. How do I use Bluebird with Angular?
  19. Proper way to skip a then function in Q Promises
  20. Unit-test promise-based code in Angularjs
  21. TypeError: Cannot read property ‘then’ of undefined
  22. What happens if i reject / resolve multiple times in Kriskowal’s q?
  23. Is there a way to return early in deferred promise?
  24. Promises: Repeat operation until it succeeds?
  25. How can I access the value of a promise?
  26. javascript promise not passing all arguments (using Q)
  27. Make angular.forEach wait for promise after going to next object
  28. orderBy array item value in Angular ng-repeat
  29. How to make POST requests with the FormData API
  30. AngularJS abort all pending $http requests on route change

Leave a Comment