How do I use Bluebird with Angular?
I tried using Angular with Bluebird promises:
HTML:
<body ng-app="HelloApp">
<div ng-controller="HomeController">{{name}} {{also}}</div>
</body>
JS:
// javascript
var app = angular.module('HelloApp', []);
app.controller("HomeController", function ($scope) {
var p = Promise.delay(1000).then(function () {
$scope.name = "Bluebird!";
console.log("Here!", $scope.name);
}).then(function () {
$scope.also = "Promises";
});
$scope.name = "$q";
$scope.also = "promises";
});
window.app = app;
[Fiddle]
However, no matter what I tried, it kept staying "$q promises" and did not update. Except if I added a manual $scope.$apply which I'd rather avoid.
How do I get Bluebird to work with AngularJS?
(I know it's possible since $q does it)
I'm using Bluebird 2.0 which I got here.
Answer
This is possible, and even quite easy!
Well, if we look at how Angular's own promises work, we need to get Bluebird to $evalAsync somewhere in order to get the exact same behavior.
If we do that, the fact both implementations are Promises/A+ compliant means we can interop between $q code and Bluebird code, meaning we can use all of Bluebird's features in Angular code freely.
Bluebird exposes this functionality, with its Promise.setScheduler functionality:
// after this, all promises will cause digests like $q promises.
function trackDigests(app) {
app.run(["$rootScope",function ($rootScope) {
Promise.setScheduler(function (cb) {
$rootScope.$evalAsync(cb);
});
}]);
}
Now all we have to do is add a:
trackDigests(app);
line after the var app = ... line, and everything will work as expected. For bonus points, put Bluebird in a service so you can inject it rather than use it on the global namespace.
Here is a [Fiddle] illustrating this behavior.
Note that besides all the features Bluebird has over $q, one of the more important ones is that Bluebird will not run $exceptionHandler, but instead will automatically track unhandled rejections, so you can throw freely with Bluebird promises and Bluebird will figure them out. Moreover calling Promise.longStackTraces() can help with debugging a lot.