First of all, I decided I needed to use $http
since I couldn’t find any solution that used $resource
, nor could I get it to work on my own.
So here’s what my factory turned into, based on @Sid’s answer here, using the guide at http://www.bennadel.com/blog/2616-aborting-ajax-requests-using-http-and-angularjs.htm
.factory('AllSites',function($http,$q){
function getSites(categoryID) {
// The timeout property of the http request takes a deferred value
// that will abort the underying AJAX request if / when the deferred
// value is resolved.
var deferredAbort = $q.defer();
// Initiate the AJAX request.
var request = $http({
method: 'get',
url: 'api/categorySites/'+categoryID,
timeout: deferredAbort.promise
});
// Rather than returning the http-promise object, we want to pipe it
// through another promise so that we can "unwrap" the response
// without letting the http-transport mechansim leak out of the
// service layer.
var promise = request.then(
function( response ) {
return( response.data );
},
function() {
return( $q.reject( 'Something went wrong' ) );
}
);
// Now that we have the promise that we're going to return to the
// calling context, let's augment it with the abort method. Since
// the $http service uses a deferred value for the timeout, then
// all we have to do here is resolve the value and AngularJS will
// abort the underlying AJAX request.
promise.abort = function() {
deferredAbort.resolve();
};
// Since we're creating functions and passing them out of scope,
// we're creating object references that may be hard to garbage
// collect. As such, we can perform some clean-up once we know
// that the requests has finished.
promise.finally(
function() {
promise.abort = angular.noop;
deferredAbort = request = promise = null;
}
);
return( promise );
}
// Return the public API.
return({
getSites: getSites
});
});
Then, in my controller (route ‘A’ from my problem):
var allSitesPromise = AllSites.getSites(categoryID);
$scope.$on('$destroy',function(){
allSitesPromise.abort();
});
allSitesPromise.then(function(allSites){
// do stuff here with the result
}
I wish the factory wasn’t so messy, but I’ll take what I can get. However, now there’s a separate, related issue Here where, though the promise was cancelled, the next actions are still delayed. If you have an answer for that, you can post it there.