Why won't promise resolve in a service? - angularjs

I have a factory NewEditSvc where I'm trying to share functionality common to NewCtrl and EditCtrl. One thing I'm trying to do is get feeParameters from the server inside the service but this is not working.
angular.module('feeSuitesApp')
.factory('NewEditSvc', function($q, FeeTypesSvc){
var _feeParameters = {};
function getParameters(){
return _feeParameters;
}
function setParameters(feeType){
var promise = $q(function(resolve, reject){
FeeTypesSvc.resource.get({id: feeType.id, association: 'fee_parameters'}).
$promise.then(function(data){
resolve(data);
}, function(error){
reject(error);
})
});
promise.then(function(data){
_feeParameters = data.master;
});
}
return {
getParameters: getParameters,
setParameters: setParameters
}
});
angular.module('feeSuitesApp')
.controller('NewCtrl', function(NewEditSvc, feeType){
$scope.feeParameters = NewEditSvc.getParameters();
$scope.feeType = feeType;
$scope.setParameters = function(feeType){
NewEditSvc.setParameters(feeType);
};
$scope.setParameters($scope.feeType);
});
After my last line $scope.feeParameters is not set. But if I return the promise variable from NewEditSvc.setParameters() and then in my NewCtrl I do the following:
var promise = $scope.setParameters($scope.feeType);
promise.then(function(data){
$scope.feeParameters = data.master;
});
Then everything works. What am I doing wrong?

The problem is, that you're not returning your promise in setParameters. https://docs.angularjs.org/api/ng/service/$q/
Just add return promise.

Related

How to get .notify() in chaining promises from $q.all?

I am using chained promises in angular js with $q service and it's working fine except the information of progressCallback ? let me draw what I have done so far?
calling function from my controller in below chainable promise way
fun1()
.then(resp1){
return fun2(resp1.id);
})
.then(resp2){
return $q.all([fun3(resp2.id),fun4(resp2.name)]);
})
.then(function(resp34){
return fun5();
})
.then(success)
.catch(errorhandler)
.finally(final);
and here is my all functions signature in service
var funX = function(param) {
var d = $q.defer();
d.notify('start with funX'); // Note: it was not working so placed inside else
doSomethingASync(param, function(err,data) {
if(err) { d.reject(err);}
else { d.notify('done with funX'); d.resolve(data); }
});
return d.promise;
});
Now my question is where do I receive this d.notify() message in my controller?
trial 1
.then(resp1, info1){
return fun2(resp1.id);
});
but it's undefined
trial 2
.then(resp1, err1, info1) {
return fun2(resp1.id);
}
but still undefined?
UPDATE
I have find a way by adding second parameter in finally()
.then().catch().finally(final, notify);
and here is my function definitions.
var errorHandler = function(err) {
console.error('Error returned from function:', err);
};
var final = function() {
console.log('Called Finally');
};
var notify = function(notification) {
console.log('Notify', notification);
};
var success = function(data) {
console.log('Success data');
console.log(data);
};
Can we get each promise function notification or this is not feasible?
But Now my query changed to
How do we add a .notify for the $q.all() ?
as I understand that $q.all returns a single promise which contains all promise resolve data;

Chaining promises in Angular with $q.all

I have the following layout for a promise chain in a service...
this.getData = function(params) {
var promise = $http({}).then(function(firstdata) {
// work on the first data and then call a number of promises for fetch additional data
var promises = list.map(function(item) {
return $http({}).then(function(result2) {
// this is an amalgamation of all the data from the various calls
return finalData;
});
return $q.all(promises);
})
});
return promise;
}
Then in my controller i'm doing
myService.getData().then(function(data){
});
The issue lies in the fact that THEN in the controller executes before PROMISES (note the plural) has returned a value.
This is likely something silly but any thoughts on how to simplify this/make it work would be handy!
Currently your inner promises($q.all promise) isn't returned from promise variable. You should also return promises(plural), to make sure chain should work.
this.getData = function(params) {
var promise = $http({}).then(function(firstdata) {
// creating new promise array in `promises` function
var promises = list.map(function(item) {
return $http({}).then(function(result2) {
// this is an amalgamation of all the data from the various calls
return finalData;
});
return $q.all(promises);
});
return promises; //returning inner promise
});
return promise;
}

Meteor-Angular Service function

I'm creating an app in Angular-Meteor, and i'd like create a few functions in my services which I can use in my controllers. However those functions use the $meteor.subscribe function, which queries the database and returns a call back. In my controller I want to call that function and bind that to the $scope, but then it returns undefined, because the call back hasn't returned anything yet. Is there a solution to keep the code in the service? Any tips?
An example:
Service
angular.module('GQ').service('AuthService', ['$meteor', function($meteor)
{
console.log('AuthService init')
this.getUserAuth = function() {
var user = {};
$meteor.subscribe('isAdmin').then(function(res){
//do database query...
//loop over returned values and do a check if query matches or not
// if it does match return true
// else return false
});
// then return the value
return user.isAdmin;
}
}]);
Controller
$scope.isAdmin = AuthService.getUserAuth();
console.log($scope.isAdmin) <--- undefined
You can use angular promises (official doc).
Example for your service:
this.getUserAuth = function() {
var deferred = $q.defer();
var user = {};
$meteor.subscribe('isAdmin').then(function(res, err){
// ....
// just an example
if (!res.isAdmin) deferred.reject('not an admin');
if (err) deferred.reject(err);
else deferred.resolve(res);
});
return deferred.promise;
}
Use in your controller:
AuthService.getUserAuth()
.then(function(res){
console.log(res); // the res from service
$scope.isAdmin = res; // is asynchronous, but angular updates the scope var
}, function(err){
// error handling here
});

How to mock an angular $http call and return a promise object that behaves like $http

Is there a way to return an HttpPromise (or something similar) to mimic a call to $http? I want to set a global variable that indicates whether the real HTTP request is made or whether a fake HttpPromise object is returned with fake data.
For example, I have a service that is similar to this:
angular
.module('myservice')
.factory('MyService', ['$http', function($http) {
return {
get : function(itemId) {
if (isInTestingMode) {
// return a promise obj that returns success and fake data
}
return $http.get("/myapp/items/" + itemId);
}
};
} ]);
And in my controller, I have a call to the aforementioned service that looks similar to this:
// Somewhere in my controller
MyService.get($scope.itemId)
.success(function(data) {
$scope.item = data;
})
.error(function(data, status, headers, config) {
$scope.notFound = true;
});
I'm trying to not change the controller code; I want the success and error chaining to still work when in my "isInTestMode".
Is it possible to fake an HttpPromise in the way that I described in the service?
Below is a revised edition of the "MyService" above (a snippet) containing a success and error on the promise object. But, how do I execute the success method?
return {
get : function(itemId) {
if (isInTestingMode) {
var promise = $.defer().promise;
// Mimicking $http.get's success
promise.success = function(fn) {
promise.then(function() {
fn({ itemId : "123", name : "ItemName"}, 200, {}, {});
});
return promise;
};
// Mimicking $http.get's error
promise.error = function(fn) {
promise.then(null, function(response) {
fn("Error", 404, {}, {});
});
return promise;
};
return promise;
}
return $http.get("/myapp/items/" + itemId);
}
}
Just use the deferred method of the $qservice
var fakeHttpCall = function(isSuccessful) {
var deferred = $q.defer()
if (isSuccessful === true) {
deferred.resolve("Successfully resolved the fake $http call")
}
else {
deferred.reject("Oh no! Something went terribly wrong in your fake $http call")
}
return deferred.promise
}
And then you can call your function like an $http promise (you have to customize whatever you want to put inside of it, of course).
fakeHttpCall(true).then(
function (data) {
// success callback
console.log(data)
},
function (err) {
// error callback
console.log(err)
})
I found that this post is similar to what I was asking.
However, I wanted a way to mock my service call so that fake data could be returned instead of issuing a true HTTP request call. The best way to handle this situation, for me, is to use angular's $httpBackend service. For example, to bypass a GET request to my "items" resource BUT to not bypass GETs of my partials/templates I would do something like this:
angular
.module('myApp', ['ngMockE2E'])
.run(['$httpBackend', function($httpBackend) {
$httpBackend
.whenGET(/^partials\/.+/)
.passThrough();
$httpBackend
.whenGET(/^\/myapp\/items\/.+/)
.respond({itemId : "123", name : "ItemName"});
}]);
See this documentation for more information on $httpBackend.
I finally found a way using jasmin. $httpBackend was no option for me, as there were also non-$http-methods I needed mock on the same service. I also think that the controller test needing to specify the url is not perfect as imho the controller and its test should not need to know about it.
Here is how it works:
beforeEach(inject(function ($controller, $rootScope, $q) {
scope = $rootScope.$new();
mockSvc = {
someFn: function () {
},
someHttpFn: function () {
}
};
// use jasmin to fake $http promise response
spyOn(mockSvc, 'someHttpFn').and.callFake(function () {
return {
success: function (callback) {
callback({
// some fake response
});
},
then: function(callback) {
callback({
// some fake response, you probably would want that to be
// the same as for success
});
},
error: function(callback){
callback({
// some fake response
});
}
}
});
MyCtrl = $controller('MyCtrl', {
$scope: scope,
MyActualSvc: mockSvc
});
}));
You can implement your FakeHttp class:
var FakeHttp = function (promise) {
this.promise = promise;
this.onSuccess = function(){};
this.onError = function(){};
this.premise.then(this.onSuccess, this.onError);
};
FakeHttp.prototype.success = function (callback) {
this.onSuccess = callback;
/**You need this to avoid calling previous tasks**/
this.promise.$$state.pending = null;
this.promise.then(this.onSucess, this.onError);
return this;
};
FakeHttp.prototype.error = function (callback) {
this.onError = callback;
/**You need this to avoid calling previous tasks**/
this.promise.$$state.pending = null;
this.promise.then(this.onSuccess, this.onError);
return this;
};
Then in your code, you would return a new fakeHttp out of the promise.
if(testingMode){
return new FakeHttp(promise);
};
The promise must be asynchronous, otherwise it won't work. For that you can use $timeout.
easy peasy!
You can do it using angular-mocks-async like so:
var app = ng.module( 'mockApp', [
'ngMockE2E',
'ngMockE2EAsync'
]);
app.run( [ '$httpBackend', '$q', function( $httpBackend, $q ) {
$httpBackend.whenAsync(
'GET',
new RegExp( 'http://api.example.com/user/.+$' )
).respond( function( method, url, data, config ) {
var re = /.*\/user\/(\w+)/;
var userId = parseInt(url.replace(re, '$1'), 10);
var response = $q.defer();
setTimeout( function() {
var data = {
userId: userId
};
response.resolve( [ 200, "mock response", data ] );
}, 1000 );
return response.promise;
});
}]);

AngularJS : chaining http promises $q in a service

i have problems when it comes to $http promises in angularjs. i am doing this in my service: (the getSomething function should chain two promises)
the second function uses a external callback function!
app.service('blubb', function($http, $q) {
var self = this;
this.getSomething = function(uri, data) {
return self.getData(uri).then(function(data2) {
return self.compactData(uri, data2);
});
};
this.getData = function(uri) {
var deferred = $q.defer();
$http.get(uri).success(function(data) {
deferred.resolve(data);
}).error(function() {
deferred.reject();
});
return deferred.promise;
};
this.compactData = function(uri, data) {
var deferred = $q.defer();
/* callback function */
if(!err) {
console.log(compacted);
deferred.resolve(compacted);
} else {
console.log(err);
deferred.reject(err);
}
/* end of function */
return deferred.promise;
};
});
when i use the service in my controller it doesn't output the console.log:
blubb.getSomething(uri, input).then(function(data) {
console.log(data)
});
edit:
if i define the callback function by myself in 'compactData' it works, but i am using "jsonld.compact" from https://raw.github.com/digitalbazaar/jsonld.js/master/js/jsonld.js and THIS doesn't work!
jsonld.compact(input, context, function(err, compacted) {
if(!err) {
console.log(compacted);
deferred.resolve(compacted);
} else {
deferred.reject('JSON-LD compacting');
}
});
i am getting the console.log output in jsonld.compact but the resolve doesn't work and i don't know why..
it only works with $rootScope.$apply(deferred.resolve(compacted));
I'm using chaining promises like this:
$http.get('urlToGo')
.then(function(result1) {
console.log(result1.data);
return $http.get('urlToGo');
}).then(function(result2) {
console.log(result2.data);
return $http.get('urlToGo');
}).then(function(result3) {
console.log(result3.data);
});
Chaining promises works here : jsfiddle
In your implementation, if $http.get or compactData goes wrong your console.log(data) will not be call.
You should maybe catch errors :
blubb.getSomething(uri, input).then(function(data) {
console.log(data);
}, function(err) {
console.log("err: " + err);
});
Whenever you use an external (external to AngularJS) callback that runs in a new turn/tick, you have to call $apply() on the appropriate scope after it has been invoked. This lets AngularJS know it has to update. You'll probably want to make sure you're only calling it once -- after all of the promises have been resolved. As an aside, jsonld.js provides a promises/future API, so if you're already using promises, you don't have to do that wrapper code above. Instead you can do:
var promisesApi = jsonld.promises();
var promise = promisesApi.compact(input, context);
// do something with the promise
I would suggest you to use a Factory instead of a service.
Just return the function from the factory and use it in your controller

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