Given a Ajax request in AngularJS
$http.get("/backend/").success(callback);
what is the most effective way to cancel that request if another request is launched (same backend, different parameters for instance).
This feature was added to the 1.1.5 release via a timeout parameter:
var canceler = $q.defer();
$http.get('/someUrl', {timeout: canceler.promise}).success(successCallback);
// later...
canceler.resolve(); // Aborts the $http request if it isn't finished.
Cancelling Angular $http Ajax with the timeout property doesn't work in Angular 1.3.15.
For those that cannot wait for this to be fixed I'm sharing a jQuery Ajax solution wrapped in Angular.
The solution involves two services:
HttpService (a wrapper around the jQuery Ajax function);
PendingRequestsService (tracks the pending/open Ajax requests)
Here goes the PendingRequestsService service:
(function (angular) {
'use strict';
var app = angular.module('app');
app.service('PendingRequestsService', ["$log", function ($log) {
var $this = this;
var pending = [];
$this.add = function (request) {
pending.push(request);
};
$this.remove = function (request) {
pending = _.filter(pending, function (p) {
return p.url !== request;
});
};
$this.cancelAll = function () {
angular.forEach(pending, function (p) {
p.xhr.abort();
p.deferred.reject();
});
pending.length = 0;
};
}]);})(window.angular);
The HttpService service:
(function (angular) {
'use strict';
var app = angular.module('app');
app.service('HttpService', ['$http', '$q', "$log", 'PendingRequestsService', function ($http, $q, $log, pendingRequests) {
this.post = function (url, params) {
var deferred = $q.defer();
var xhr = $.ASI.callMethod({
url: url,
data: params,
error: function() {
$log.log("ajax error");
}
});
pendingRequests.add({
url: url,
xhr: xhr,
deferred: deferred
});
xhr.done(function (data, textStatus, jqXhr) {
deferred.resolve(data);
})
.fail(function (jqXhr, textStatus, errorThrown) {
deferred.reject(errorThrown);
}).always(function (dataOrjqXhr, textStatus, jqXhrErrorThrown) {
//Once a request has failed or succeeded, remove it from the pending list
pendingRequests.remove(url);
});
return deferred.promise;
}
}]);
})(window.angular);
Later in your service when you are loading data you would use the HttpService instead of $http:
(function (angular) {
angular.module('app').service('dataService', ["HttpService", function (httpService) {
this.getResources = function (params) {
return httpService.post('/serverMethod', { param: params });
};
}]);
})(window.angular);
Later in your code you would like to load the data:
(function (angular) {
var app = angular.module('app');
app.controller('YourController', ["DataService", "PendingRequestsService", function (httpService, pendingRequestsService) {
dataService
.getResources(params)
.then(function (data) {
// do stuff
});
...
// later that day cancel requests
pendingRequestsService.cancelAll();
}]);
})(window.angular);
Cancelation of requests issued with $http is not supported with the current version of AngularJS. There is a pull request opened to add this capability but this PR wasn't reviewed yet so it is not clear if its going to make it into AngularJS core.
If you want to cancel pending requests on stateChangeStart with ui-router, you can use something like this:
// in service
var deferred = $q.defer();
var scope = this;
$http.get(URL, {timeout : deferred.promise, cancel : deferred}).success(function(data){
//do something
deferred.resolve(dataUsage);
}).error(function(){
deferred.reject();
});
return deferred.promise;
// in UIrouter config
$rootScope.$on('$stateChangeStart', function (event, toState, toParams, fromState, fromParams) {
//To cancel pending request when change state
angular.forEach($http.pendingRequests, function(request) {
if (request.cancel && request.timeout) {
request.cancel.resolve();
}
});
});
For some reason config.timeout doesn't work for me. I used this approach:
let cancelRequest = $q.defer();
let cancelPromise = cancelRequest.promise;
let httpPromise = $http.get(...);
$q.race({ cancelPromise, httpPromise })
.then(function (result) {
...
});
And cancelRequest.resolve() to cancel. Actually it doesn't not cancel a request but you don't get unnecessary response at least.
Hope this helps.
This enhances the accepted answer by decorating the $http service with an abort method as follows ...
'use strict';
angular.module('admin')
.config(["$provide", function ($provide) {
$provide.decorator('$http', ["$delegate", "$q", function ($delegate, $q) {
var getFn = $delegate.get;
var cancelerMap = {};
function getCancelerKey(method, url) {
var formattedMethod = method.toLowerCase();
var formattedUrl = encodeURI(url).toLowerCase().split("?")[0];
return formattedMethod + "~" + formattedUrl;
}
$delegate.get = function () {
var cancelerKey, canceler, method;
var args = [].slice.call(arguments);
var url = args[0];
var config = args[1] || {};
if (config.timeout == null) {
method = "GET";
cancelerKey = getCancelerKey(method, url);
canceler = $q.defer();
cancelerMap[cancelerKey] = canceler;
config.timeout = canceler.promise;
args[1] = config;
}
return getFn.apply(null, args);
};
$delegate.abort = function (request) {
console.log("aborting");
var cancelerKey, canceler;
cancelerKey = getCancelerKey(request.method, request.url);
canceler = cancelerMap[cancelerKey];
if (canceler != null) {
console.log("aborting", cancelerKey);
if (request.timeout != null && typeof request.timeout !== "number") {
canceler.resolve();
delete cancelerMap[cancelerKey];
}
}
};
return $delegate;
}]);
}]);
WHAT IS THIS CODE DOING?
To cancel a request a "promise" timeout must be set.
If no timeout is set on the HTTP request then the code adds a "promise" timeout.
(If a timeout is set already then nothing is changed).
However, to resolve the promise we need a handle on the "deferred".
We thus use a map so we can retrieve the "deferred" later.
When we call the abort method, the "deferred" is retrieved from the map and then we call the resolve method to cancel the http request.
Hope this helps someone.
LIMITATIONS
Currently this only works for $http.get but you can add code for $http.post and so on
HOW TO USE ...
You can then use it, for example, on state change, as follows ...
rootScope.$on('$stateChangeStart', function (event, toState, toParams) {
angular.forEach($http.pendingRequests, function (request) {
$http.abort(request);
});
});
here is a version that handles multiple requests, also checks for cancelled status in callback to suppress errors in error block. (in Typescript)
controller level:
requests = new Map<string, ng.IDeferred<{}>>();
in my http get:
getSomething(): void {
let url = '/api/someaction';
this.cancel(url); // cancel if this url is in progress
var req = this.$q.defer();
this.requests.set(url, req);
let config: ng.IRequestShortcutConfig = {
params: { id: someId}
, timeout: req.promise // <--- promise to trigger cancellation
};
this.$http.post(url, this.getPayload(), config).then(
promiseValue => this.updateEditor(promiseValue.data as IEditor),
reason => {
// if legitimate exception, show error in UI
if (!this.isCancelled(req)) {
this.showError(url, reason)
}
},
).finally(() => { });
}
helper methods
cancel(url: string) {
this.requests.forEach((req,key) => {
if (key == url)
req.resolve('cancelled');
});
this.requests.delete(url);
}
isCancelled(req: ng.IDeferred<{}>) {
var p = req.promise as any; // as any because typings are missing $$state
return p.$$state && p.$$state.value == 'cancelled';
}
now looking at the network tab, i see that it works beatuifully. i called the method 4 times and only the last one went through.
You can add a custom function to the $http service using a "decorator" that would add the abort() function to your promises.
Here's some working code:
app.config(function($provide) {
$provide.decorator('$http', function $logDecorator($delegate, $q) {
$delegate.with_abort = function(options) {
let abort_defer = $q.defer();
let new_options = angular.copy(options);
new_options.timeout = abort_defer.promise;
let do_throw_error = false;
let http_promise = $delegate(new_options).then(
response => response,
error => {
if(do_throw_error) return $q.reject(error);
return $q(() => null); // prevent promise chain propagation
});
let real_then = http_promise.then;
let then_function = function () {
return mod_promise(real_then.apply(this, arguments));
};
function mod_promise(promise) {
promise.then = then_function;
promise.abort = (do_throw_error_param = false) => {
do_throw_error = do_throw_error_param;
abort_defer.resolve();
};
return promise;
}
return mod_promise(http_promise);
}
return $delegate;
});
});
This code uses angularjs's decorator functionality to add a with_abort() function to the $http service.
with_abort() uses $http timeout option that allows you to abort an http request.
The returned promise is modified to include an abort() function. It also has code to make sure that the abort() works even if you chain promises.
Here is an example of how you would use it:
// your original code
$http({ method: 'GET', url: '/names' }).then(names => {
do_something(names));
});
// new code with ability to abort
var promise = $http.with_abort({ method: 'GET', url: '/names' }).then(
function(names) {
do_something(names));
});
promise.abort(); // if you want to abort
By default when you call abort() the request gets canceled and none of the promise handlers run.
If you want your error handlers to be called pass true to abort(true).
In your error handler you can check if the "error" was due to an "abort" by checking the xhrStatus property. Here's an example:
var promise = $http.with_abort({ method: 'GET', url: '/names' }).then(
function(names) {
do_something(names));
},
function(error) {
if (er.xhrStatus === "abort") return;
});
I've tried other answers with the same problem, but none of them worked. I have the issue where I'm calling my factory and I get the undefined return.
Controller (main.js):
app.controller('MainCtrl', ['$scope','beamAPI', function($scope, beamAPI){
$scope.debug = 'Debug True';
$scope.beamFollowers = 1;
console.log(beamAPI('amtraxtge'));
}]);
Factory (beam.js):
app.factory('beamAPI', function($http) {
var APIuser = {};
APIuser = function(user) {
$http.get('https://beam.pro/api/v1/channels/' + user).
then(function(res){
console.log(res.data);
return res.data;
});
}
return APIuser;
});
Console:
undefined main.js:4
► Object beam.js:6
Your APIuser() doesn't return anything. You need to return the promise and in controller wait for promise to resolve before assigning or logging any of the data
In factory
APIuser = function(user) {
// return $http promise
return $http.get('https://beam.pro/api/v1/channels/' + user).
then(function(res){
console.log('Factory log',res.data);
return res.data;
});
}
In controller
beamAPI('amtraxtge').then(function(data){
$scope.someProperty = data;
console.log('Controller log',data);
});
I am calling my data from my api through a factory that looks like this:
app.factory('Service', ['$http', function ($http) {
var urlBase = 'http://localhost:50476/api';
var Service = {};
Service.getComp = function () {
return $http.get(urlBase + '/complaints')
};
return Service;
}]);
Then I use my controller to use the directive:
getComp();
$scope.comp = [];
function getComp() {
var deferred = $q.defer();
Service.getComp()
.success(function (comp) {
console.log('comp', comp); //returns array data
$scope.comp = comp.data;
deferred.resolve(comp);
})
.error(function (error) {
$scope.error = 'error' + error.message;
});
return deferred.promise;
}
$scope.index = 0;
$scope.complaints = $scope.comp[0];
console.log($scope.complaints); //undefined
console.log($scope.comp); //array of 0
When I try to access the items outside of the function it is undefined. I tried to look for resolutions like using $q but it is still not displaying data. When I added the deferred part my ng-repeat stops working as well.
Try this:
getComp();
$scope.comp = [];
function getComp() {
return Service.getComp()
.success(function (comp) {
$scope.comp = comp.data;
$scope.complaints = $scope.comp[0];
})
.error(function (error) {
$scope.error = 'error' + error.message;
});
}
The values are undefined when you do your logs because those lines run before your request comes back from the server. That's why setting $scope.complaints has to go into the success callback.
if you want to make sure complaints are loaded on certain states before you start your logic you can use ui-routers resolve keyword (i suppose you are using ui-router with ionic - standard package)
In you main.js
$stateProvider.state('yourState', {
resolve: {
complaints: function(Service) {
return Service.getComp();
}
}
});
in your controller you can then inject complaints
.controller('myController', function(complaints) {
$scope.complaints = complaints;
})
resolve at $stateProvider will block and wait for the promise to resolve...
I am trying to do a custom $http service that will automatically retry fail connection. My code look something like this:
angular.factory('myHttp', service);
function service($http){
var obj = {};
obj.get = function(path) {
return $http.get(path).then(function(result){
return result;
},function(result){
obj.get(path);
});
}
return obj;
}
When using it, it will be use normally almost like using $http. For example:
myHttp.get($scope.url).
then(function(response) {
console.log("It's success");
$scope.status = response.status;
$scope.data = response.data;
});
It works if the connection is success. However, if connection fail it still return respond without data that console log will display Error: response is undefined. Then, the retry will become meaningless.
How can I have the service that will do retry connection when fail?
Instead of call on service when failed do it where you call service
function doIt() {
myHttp.get($scope.url).
then(function (response) {
console.log("It's success");
$scope.status = response.status;
$scope.data = response.data;
}, function () {
doIt();
});
}
i have a factory am passing it to controller LoginCtrl
.factory('Fbdata', function(){
var service = {
data: {
apiData: []
},
login: function () {
facebookConnectPlugin.login(["email"],
function() {
facebookConnectPlugin.api("me/?fields=id,email,name,picture", ["public_info","user_birthday"],
function (results) {
service.data.apiData = results;
console.log(service.data.apiData);
return results;
},
function (error) {
console.error('FB:API', error);
});
},
function(err) {
console.error('FB:Login', err);
});
}
};
return service;
})
LoginCtrl:
.controller('LoginCtrl', function($scope, Fbdata){
$scope.login = function(){
if (!window.cordova) {
var appId = "appId";
facebookConnectPlugin.browserInit(appId);
}
$scope.loginData = Fbdata.login();
console.log(Fbdata.data.apiData);
// got empty array []
$scope.retVal= angular.copy(Fbdata.data.apiData);
};
})
the Fbdata.data.apiData return empty array and i only could see the returned data from the login success function in the console .
my template which is has LoginCtrl as controller:
<div class="event listening button" ng-click="login();">Login with Facebook</div>
<h2>{{loginData.name}}</h2>
<h2>{{retVal.name}}</h2>
There is a variety of ways to achieve this, example:
Now I have never used Cordova Facebook Plugin so I'm not sure if you need to run the api function after the log in, or how those procedures need to be ordered. But I wanted to show you an example of how to retrieve the data from the factory using your code sample. Hope that helps
Edit 2:
I have changed my code to using promises that way we make sure that we don't call one without the other being completed, I am not a fan of chaining the login and api functions within one function since it is possible(?) that you may need to call login() but don't want to call api(), please try my code and paste in your console logs in the bottom of your question.
Factory:
// Let's add promises to our factory using AngularJS $q
.factory('Fbdata', ['$q', function($q){
// You could also just replace `var service =` with `return` but I thought this
// would make it easier to understand whats going on here.
var service = {
// I generally nest result to keep it clean when I log
// So results from functions that retrieve results are stored here
data: {
login: [],
api: []
},
api: function() {
var q = $q.defer();
facebookConnectPlugin.api("me/?fields=id,email,name,picture", ["public_info","user_birthday"],
function (results) {
// assign to the object being returned
service.data.api = results;
// The data has returned successfully so we will resolve our promise
q.resolve(results);
},
function (error) {
// We reject here so we can inform the user within through the error/reject callback
q.reject(error);
console.error('FB:API', error);
});
// Now that we have either resolved or rejected based on what we received
// we will return the promise
return q.promise;
},
login: function () {
var q = $q.defer();
facebookConnectPlugin.login(["email"], function (results) {
// assign to the object being returned
service.data.login = results;
q.resolve(results);
}, function(err) {
q.reject(error);
console.error('FB:Login', err);
});
return q.promise;
}
};
return service;
}])
Controller:
.controller('LoginCtrl', function($scope, Fbdata){
$scope.login = function(){
if (!window.cordova) {
var appId = "appid";
facebookConnectPlugin.browserInit(appId);
}
// By using the promises in our factory be can ensure that API is called after
// login by doing the following
// then(success, reject) function allows us to say once we have a return, do this.
Fbdata.login().then(function () {
$scope.loginData = Fbdata.data.login;
// Check what was returned
console.log('loginData', $scope.loginData);
Fbdata.api().then(function () {
$scope.apiData = Fbdata.data.api;
console.log('apiData', $scope.apiData);
}, function () {
// Tell the user that the api failed, if necessary
});
}, function () {
// Tell the user that the log in failed
});
};
});