Setting up a service with $q - angularjs

I am trying to set up a service with $q (and resangular), so in a controller I could then call
myservice.get.then(function(data){
//use data
}
Right now I have
.service(urlService,
function($q, Restangular) {
this.get = function(newURl) {
return $q(function(resolve, reject) {
Restangular.one(newURl).get()
.then(resolve)
.catch(reject);
});
};
}
If I inject into a controller and call
urlService.get(newUrlObject).then(function(data){
console.log(data);
});
this does not seem to work. I could use some help getting this right, thanks!

You have to call resolve and reject:
return $q(function(resolve, reject) {
Restangular.one(newURl).get()
.then(function(data) {
resolve(data)
})
.catch(function(whatever) {
reject(whatever);
});
But Restangular.one(newURl).get() already returns a promise, so wrapping the code into another deferred doesn't make much sense. Id rather use the promise directly:
this.get = function(newURl) {
return Restangular.one(newURl).get();
};

May be you should use $q.refer, like this:
.service(urlService,
function($q, Restangular) {
this.get = function(newURl) {
var deferred = $q.defer();
Restangular.one(newURl).get()
.then(function() {
deferred.resolve();
})
.catch(function(){
deferred.reject();
});
return deferred.promise();
};
}
Reference: https://docs.angularjs.org/api/ng/service/$q

Related

angular 1.6.1 http request from service

angular 1.6.1 has removed .success and .error in service $http for use .then and .catch.
Now my answer is:
It makes sense that I have written in my code? because now I'm confused on how the controller talks to the service
I have a controller for login (example):
LoginCTRL
User.login(data).then(
function(response){
//do something
},function(err){
//do somethig
});
And I have User service:
myapp.service('User', function User($q, $http) {
return {
login: function(credentials){
return $http.post('login',{data:data}).then(function onSuccess(response) {
return response;
}).catch(function onError(response){
return response;
});
},
}
It's correct write service.method().then in controller, now that there is no more $q.defer().resolve(data) or $q.defer().reject(reason)
try:
myapp.service('User', function User($q, $http) {
return {
login: function(credentials) {
var deferred = $q.defer();
$http.post('login', {
data: data
}).then(onSuccess, onFailure);
function onSuccess(response) {
deferred.resolve(response);
}
function onFailure(response) {
deferred.reject(response);
}
return deferred.promise;
}
}
}

Karma testing controller that calls service with http

Can someone please tell me the best way to run tests on my controller function getData and the factory function too. I've very confused and don't know where to start. How would you write tests for the code below?
myApp.controller('myController', ['$scope', 'myFactory', function ($scope, myFactory) {
$scope.getData = function(id) {
var promise = myFactory.GetData('/dta/GetData?Id=' + id);
promise
.then(function (success) {
$scope.result = success;
}, function (error) {
$scope.error = true;
});
}
});
myApp.factory('myFactory', ['$http', function ($http) {
return {
GetData: function (url) {
return $http.get(url)
.then(function (response) {
return response.data;
}, function (error) {
return error;
});
}
}
}]);
You'll want to test each component in isolation (that's what unit tests are for). So something like this for the controller
describe('myController test', () => {
let scope, myFactory;
beforeEach(() => {
myFactory = jasmine.createSpyObj('myFactory', ['GetData']);
module('your-module-name');
inject(function($rootScope, $controller) {
scope = $rootScope.$new();
$controller('myController', {
$scope: scope,
myFactory: myfactory
});
});
});
it('getData assigns result on success', inject(function($q) {
let id = 1, success = 'success';
myFactory.GetData.and.returnValue($q.when(success));
scope.getData(id);
expect(myFactory.GetData).toHaveBeenCalledWith('/dta/GetData?Id=' + id);
scope.$digest(); // resolve promises
expect(scope.result).toBe(success);
}));
it('getData assigns error on rejections', inject(function($q) {
myFactory.GetData.and.returnValue($q.reject('error'));
scope.getData('whatever');
scope.$digest();
expect(scope.error).toEqual(true);
}));
});
For your factory, you would create a separate describe and inject and configure $httpBackend. There are plenty of example in the documentation.
FYI, you should omit the error handler in your factory, ie
return $http.get(url).then(response => response.data);
or if you don't like ES2015
return $http.get(url).then(function(response) {
return response.data;
});
as you are currently converting a failed request into a successful promise.
In fact, I'd go a bit further to make your GetData factory more useful than a mere $http wrapper
GetData: function(id) {
return $http.get('/dta/GetData', {
params: { Id: id }
}).then(function(res) {
return res.data;
});
}

How can I use angularjs promise chain in a service and controller?

I found this plnkr link on the web but I need use it with 2 or 3 more ajax calls which doesn't require an argument from the first ajax call. How can I do it with error handling?
var app = angular.module("app", []);
app.service("githubService", function($http, $q) {
var deferred = $q.defer();
this.getAccount = function() {
return $http.get('https://api.github.com/users/haroldrv')
.then(function(response) {
// promise is fulfilled
deferred.resolve(response.data);
return deferred.promise;
}, function(response) {
// the following line rejects the promise
deferred.reject(response);
return deferred.promise;
});
};
});
app.controller("promiseController", function($scope, $q, githubService) {
githubService.getAccount()
.then(
function(result) {
// promise was fullfilled (regardless of outcome)
// checks for information will be peformed here
$scope.account = result;
},
function(error) {
// handle errors here
console.log(error.statusText);
}
);
});
http://plnkr.co/edit/kACAcbCUIGSLRHV0qojK?p=preview
You can use $q.all
var promises=[
$http.get(URL1),
$http.get(URL2),
$http.get(URL3),
$http.get(URL4)
];
$q.all(promises).then(function(response){
console.log('Response of Url1', response[0]);
console.log('Response of Url2', response[1]);
console.log('Response of Url3', response[2]);
console.log('Response of Url4', response[3]);
}, function(error){
});
I have forked your plunkr with $q
First you should make deferred variable local for each ajax call you want to return a promise. So, you have to create 2-3 functions (as many as your ajax calls) and keep them in an array. Then you should use:
$q.all([ajax1,ajax2,ajax3]).then(function(values){
console.log(values[0]); // value ajax1
console.log(values[1]); // value ajax2
console.log(values[2]);}); //value ajax3
example:
function ajax_N() {
var deferred = $q.defer();
http(...).then((response) => {
deferred.resolve(response);
}, (error) => {
deferred.reject(error);
});
return deferred.promise;
}
$q.all([
ajax_1,ajax_2,ajax_3
]).then(function(values) {
console.log(values);
return values;
});
Use $q.all in this case. It will call getAccount and getSomeThing api same time.
var app = angular.module("app", []);
app.service("githubService", function($http, $q) {
return {
getAccount: function () {
return $http.get('https://api.github.com/users/haroldrv');
},
getSomeThing: function () {
return $http.get('some thing url');
}
};
});
app.controller("promiseController", function($scope, $q, githubService) {
function initData () {
$q.all([githubService.getAccount(), githubService.getSomeThing()])
.then(
function (data) {
$scope.account = data[0];
$scope.someThing = data[1];
},
function (error) {
}
);
}
});

Why do i have to use return twice and how does it work?

I wrote a wrapper for the $http service in angular using a service. Why do i have to return bothe the http call and my result to have it available in a controller?
this is the function in the service:
this.fetchData = function(url, parameters)
{
if (parameters)
{
return $http.get(url, {params: parameters}).then(
function (response) {
console.log(response);
return response.data.data;
},
function (response) {
console.log(response);
});
}
else
{
return $http.get(url).then(
function (response) {
console.log(response);
},
function (response) {
console.log(response);
}
);
}
}
and this is where i call it in the controller:
test.fetchData('/jewelry-room/move-user.action', {user:2000, task:7}).then(
function (response) {
console.log(response);
},
function (response) {
console.log(response);
}
);
Because what you return from the factory is a promise: return $http.get().then(). Since your factory has the callback function inside then, so the promise is resolved. In this case, the function inside controller then block will not be called.
You need to return again in order to have access to the response data inside the controller.
Alternatively, just return $http.get() from the factory.
You could just return the promise to your controller by using $q:
var fetchData = function (url, params) {
if (params) {
var deferred = $q.defer();
$http.get(url, {params: params}).success(deferred.resolve).error(deferred.reject)
return deferred.promise;
} else {
var deferred = $q.defer();
$http.get(url).success(deferred.resolve).error(deferred.reject)
return deferred.promise;
}
}
Then inside your controller you can handle the promise.

reject promise when returning $http from service

I know I could do this:
angular.module('app.services').service('Resources', function ($q) {
this.ProductData = function() {
var deferred = $q.defer();
$http.get(url)
.then(function(result) {
deferred.resolve(result);
}, function() {
defered.reject("error");
});
return deferred.promise;
}
});
But could I avoid creating deferred obj, but still be able to do both resolve and reject?
angular.module('app.services').service('Resources', function () {
this.ProductData = function() {
return $http.get(url)
.then(function (result) {
// how would I do 'deferred.resolve or deferred.reject' here?
}, function () {
// how would I do 'deferred.reject' here?
});
}
});
You are right to avoid creating a deferred and another promise for $http.
If you need to reject the promise while the actual $http call has succeeded, you'd need to return $q.reject():
return $http.get(url)
.then(function(result){
if (result.data.length === 0) return $q.reject("error");
return result;
}

Resources