Angularjs how to cancel resource promise $http
.factory('AllSites',function($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
});
});