$q.all promise is never makes to then - angularjs

Question

One of my promises during feeds.forEach cycle ends up with error. Maybe because this in LoadData never executes line $rootScope.links = urls; which is inside then. How to fix it?
app.service('LoadData', ['FeedService', 'EntryStateUrlService', '$q',
function(FeedService, EntryStateUrlService, $q) {
this.loadData = function(feedSrc) {
FeedService.parseFeed(feedSrc).then(EntryStateUrlService.getEntryStateUrl).then(function(data) {
console.log(data);
$rootScope.links = data;
});
}
}
]);
app.service('FeedService', function($http, $q) {
this.parseFeed = function(url) {
var deferred = $q.defer();
$http.jsonp('//ajax.googleapis.com/ajax/services/feed/load?v=1.0&callback=JSON_CALLBACK&q=' + encodeURIComponent(url))
.success(function(res) {
deferred.resolve(res.data.responseData.feed.entries);
}).error(function() {
deferred.reject();
});
return deferred.promise;
}
});
app.service('EntryStateUrlService', ['$state', '$q',
function($state, $q) {
this.getEntryStateUrl = function(feeds) {
var deferred = $q.defer();
var idx = 0,
promises = [],
promise = null;
feeds.forEach(function(e) {
promise = $http.jsonp(e.link).success(function(data) {
/*stuff*/
e['entryStateUrl'] = data.link; // UPDATED
deferred.resolve(data);
});
promises.push(promise);
}); //forEach
return $q.all(promises);
}
}
]);
UPDATE
I don't really understand how $q.all as a big promise object composite of many other promises will deliver data to service LoadData....
UPDATE2
It seems like since one promise fails (because the one of the urls is invalid) $q.all fails and never makes to then(). How to go around that? I need to get all data from all successful promises.

Answer 1

One thing is you'll need to inject $rootScope in order to use it:
app.service('LoadData', ['FeedService', 'EntryStateUrlService', '$q', '$rootScope',
function(FeedService, EntryStateUrlService, $q, $rootScope) {
//...
}
]);
Also in the Q library there's a method called allSettled that will allow you to view all the promise results even if one fails. The angular $q does not have this method, but several people have found it useful so they've created extensions for it. Here's an example of one on a Github Gist:
angular.module('qAllSettled', []).config(function($provide) {
$provide.decorator('$q', function($delegate) {
var $q = $delegate;
$q.allSettled = function(promises) {
return $q.all(promises.map(function(promise) {
return promise.then(function(value) {
return { state: 'fulfilled', value: value };
}, function(reason) {
return { state: 'rejected', reason: reason };
});
}));
};
return $q;
});
});
Using this method will return all results, whether rejected or not. The returned object will have a state property that will tell you the status of the promise:
return $q.allSettled(promises);
Then you can check the status of each promise and add it to the links as needed:
FeedService.parseFeed(feedSrc)
.then(EntryStateUrlService.getEntryStateUrl)
.then(function(results) {
$scope.links = [];
results.forEach(function (result) {
if (result.state === "fulfilled") {
$scope.links.push(result.value);
} else {
var reason = result.reason;
}
});
});
Plunker Demonstration