bind controllers to service with ajax promise - javascript

I'm new to angularjs. In my webapp I'm trying to work with user contacts as follows.
SERVICE
app.service('Contacts', function ($http,$timeout,$q) {
return {
getData: function() {
var defer = $q.defer();
$http.get('../ListContacts')
.success(function(data) {
defer.resolve(data);
});
return defer.promise;
}
}
});
ContactsController, OtherControllers
$scope.contactsBook = {};
...
Contacts.getData().then(function(data) {
$scope.contactsBook = data;
});
I found the above method somewhere in SO itself. I used it because I don't want to use separate module for Contacts.
I can get data at page load. I can update my contacts at server through ajax posts (from ContactsController). Now I only need a way to update(/refresh) the list automatically in all controllers. How can I achieve that.
I found these three links related but being a newbie I'm unable to figure my way out.

While it is understandable that you may not want to update your current architecture, it may be necessary to adjust your calls slightly if you want to be able to easily share data between controllers via a service.
One flexible approach is to store the data in your service and register watchers in each controller. This allows you to call the service update from one controller (the Contacts controller) and have the change be reflected in all consuming controllers. Note the service is mocked.
You can find the working plunker example here.
Contacts Service:
var app = angular.module('app', []);
app.service('contactsService', function ($http) {
var contacts = [];
return {
loadData: function() {
var mockGet = $q.defer();
var data = [
{ id: 1, name: 'Jack' },
{ id: 2, name: 'Jill' }
];
contacts = data;
mockGet.resolve(contacts);
return mockGet.promise;
},
retrieveNewData: function() {
var mockGet = $q.defer();
var data = [
{ id: 1, name: 'Jack' },
{ id: 2, name: 'Jill' },
{ id: 3, name: 'Bob' },
{ id: 4, name: 'Susan' }
];
contacts = data;
mockGet.resolve(contacts);
return mockGet.promise;
},
getContacts: function () {
return contacts;
}
}
});
Contacts Controller:
app.controller('ContactsCtrl', ['$scope', 'contactsService',
function ($scope, contactsService) {
var vm = this;
vm.contacts = [];
vm.loadData = loadData;
vm.retrieveNewData = retrieveNewData;
$scope.$watch(angular.bind(contactsService, function () {
return contactsService.getContacts();
}), function (newVal) {
vm.contacts = newVal;
});
function loadData() {
contactsService.loadData();
}
function retrieveNewData() {
contactsService.retrieveNewData();
}
}
]);
Other Controller:
app.controller('OtherCtrl', ['$scope', 'contactsService',
function($scope, contactsService) {
var vm = this;
vm.contacts = [];
$scope.$watch(angular.bind(contactsService, function () {
return contactsService.getContacts();
}), function (newVal) {
vm.contacts = newVal;
});
}
]);

You can do
Contacts.getData().then(function(data) {
$scope.contactsBook = data;
$scope.$emit('contacts:updated', data);
});
And then, where you need to notify the controller about the update:
$rootScope.$on('contacts:updated', function(e, contacts) {
$scope.contacts = contacts;
});
Another approach
The service is holding the current contacts list
app.service('Contacts', function ($http,$timeout,$q) {
this.currentList = [];
this.getData = function() {
var defer = $q.defer();
$http.get('../ListContacts')
.success(function(data) {
defer.resolve(data);
});
return defer.promise;
}
});
In your controller:
Contacts.getData().then(function(data) {
$scope.contactsBook = data;
Contacts.currentList = data;
});
In other controller:
controller('AnotherController', function($scope, Contacts) {
$scope.contacts = Contacts.currentList;
});

If you are going to return an object literal you will need to turn your .service() into a .factory() module . In this case I'll be using a service module .
Example
Your service .
app.service('Contacts', function ($http,$timeout,$q) {
var Contacts = this;
contacts.getData = function() {
var defer = $q.defer();
$http.get('../ListContacts')
.success(function(data) {
defer.resolve(data);
});
return defer.promise;
}
}
return Contacts;
});
You will then need to inject this server into your ContactsController .
app.controller('ContactsController', function(Contacts){
$scope.data = null;
$scope.init = function(){
Contacts.getData().then(function(response){
$scope.data = response;
})
}
})
now data can be used in dom
Example
<li ng-repeat="x in data">{{x.name}}</li>

Related

resolving business treatment in service with ngResource

I have an AngularJs application working with components and several modules. I created a plunker example to present my problem here.
I have my NavbarComponent where I declared my Controller where I inject my service called NavbarService.
In the NavbarService, I inject a factory resource to make my Rest call, once this call is made I'm trying to made some treatment on the response before returning it back to the controller, in this example I just apply a simple filter on it, but it doesn't work. If I omit my treatment and return only the categories, the code works and you can visualize a list of two.
I can make my treatment in the controller but this is a bad practice 'cause I believe it should be done in the Service, secondly since it's an asynchronous response I must do something like this to make it work, which is really really ugly:
navbarService.getCategories().$promise.then(function (response) {
console.log("controller", response[0].category);
vm.categories = categoryFilter(response[0].category);
}, function (error) {
console.log("an error occured");
});
Can someone please guide me through this, I'm out of solutions. Thank you
Another simple way is to pass a callback function to service from you component like this
'use strict';
angular.module('navbar').component('appNavbar', {
templateUrl: "navbar.template.html",
controller: [ 'navbarService', function appNavbarController(navbarService) {
var vm = this;
navbarService.getCategories(function(data){
// this will be called when service will get the response and filter function has filtered the response
vm.categories = data;
});
}]
});
Now service should be like this
'use strict';
angular.module('navbar').service('navbarService', ['categoryResourceService', 'categoryFilter', function(categoryResourceService, categoryFilter) {
var vm = this;
vm.getCategories = function(callback) {
categoryResourceService.query(function(response) {
console.log("[NavbarService] response:", response);
callback(categoryFilter(response));
}, function(error) {
console.log("[NavbarService] error:", error);
});
//return vm.categories;
}
}]);
Filter will be like this
'use strict';
angular.module('navbar').filter('category', function() {
return function(categories) {
var categoryIds = ['World'];
var result = [];
angular.forEach(categoryIds, function (categoryId) {
angular.forEach(categories, function (category) {
if (category.name == categoryId) {
console.log("Match");
result.push(category);
}
});
});
return result;
};
});
Your filter should be like this and it should be called in transformResponse in $resource query instead of service, i hope this will help you
'use strict';
angular.module('navbar').filter('category', function() {
return function(categories) {
var categoryIds = ['World'];
var result = [];
angular.forEach(categoryIds, function (categoryId) {
angular.forEach(categories, function (category) {
if (category.name == categoryId) {
console.log("Match");
result.push(category);
}
});
});
return result;
};
});
Your categoryResource.service should be like this
angular.module('shared').factory('categoryResourceService',
['$resource','categoryFilter', function($resource, categoryFilter) {
var provider = "categories.json";
var params = {
id: '#id'
};
return $resource(provider, params, {
query: {
isArray: true,
method: 'GET',
params: {},
transformResponse: function(categories) {
var results = categoryFilter(angular.fromJson(categories));
console.log("[categoryResourceService] filtered response:", results);
return results;
}
}
});
}]);
navbar.service should be like this simply
'use strict';
angular.module('navbar')
.service('navbarService', [ 'categoryResourceService', function (categoryResourceService) {
var vm = this;
vm.getCategories = function(){
vm.categories = categoryResourceService.query(function(response){
console.log("[NavbarService] response:", response);
}, function(error){
console.log("[NavbarService] error:", error);
});
return vm.categories;
}
}]);
And components like this
'use strict';
angular.module('navbar').component('appNavbar', {
templateUrl: "navbar.template.html",
controller: [ 'navbarService', function appNavbarController(navbarService) {
var vm = this;
vm.categories = navbarService.getCategories();
}]
});

angular get and set atributes via service

i can't find a solution to this, basicly everytime i do a login, i want to store the user that i get from the node end point in the service, after that in my main Controller i should get the name of the user, but that never happen, dunno why
here is the code:
app.controller('MainCtrl', function ($scope, $state,$location,$http,user) {
$scope.user = {
nome: user.getProperty()
};
$scope.showRegister = function () {
$state.go('register');
}
$scope.showLogin = function () {
$state.go('login');
}
});
app.controller('loginController', function ($scope, $http, $state,user) {
$scope.login = function () {
var data = {};
data.password = $scope.loja.password;
data.email = $scope.loja.email;
$http.post('http://localhost:8080/login/',data)
.success(function (data) {
console.log(data);
user.setProperty(data.nome);
$state.go('home');
})
.error(function (statusText) {
console.log("failed");
});
}
});
user service
app.service('user', function () {
var property = {};
return {
getProperty: function () {
return property.nome;
},
setProperty: function (value) {
property.nome = value;
}
};
});
You could just watch your service for changes by adding this code to your MainCtrl:
$scope.$watch(function () { return user.getProperty();}, updateProp, true);
function updateProp(newValue, oldValue) {
$scope.user = {
nome: newValue
};
}
updateProp gets executed everytime the value of user.getProperty() changes.
Your main issue is with your MainCtrl . In the initial execution of MainCtrl there is no value set into your service so its get blank. MainCtrl executes before setting the value in the service.
$scope.user = {
nome: user.getProperty()
};
this code should be executed after setting the value in the service but it executes in the initialization of controller.
You can get the reference from the fiddle below.
http://jsfiddle.net/ADukg/9799/

Mock factory on controller test

this is my controller:
angular
.module('studentsApp')
.controller('StudentsController', StudentsController);
function StudentsController($scope, StudentsFactory) {
$scope.students = [];
$scope.specificStudent= {};
var getStudents = function() {
StudentsFactory.getStudents().then(function(response) {
if($scope.students.length > 0){
$scope.students = [];
}
$scope.students.push(response.data);
});
};
}
This is my factory:
angular.module('studentsApp')
.factory('StudentsFactory', function($http) {
var base_url = 'http://localhost:3000';
var studentsURI = '/students';
var studentURI = '/student';
var config = {
headers: {
'Content-Type': 'application/json'
}
};
return {
getStudents: function() {
return $http.get(base_url + studentsURI);
}
};
});
And here is how I'm trying to unit test the controller:
describe('Controller: Students', function() {
var StudentsController, scope, StudentsFactory;
beforeEach(function() {
module('studentsApp');
inject(function($rootScope, $controller, $httpBackend, $injector) {
scope = $rootScope.$new();
httpBackend = $injector.get('$httpBackend');
StudentsFactory = $injector.get('StudentsFactory');
StudentsController = $controller('StudentsController', {
$scope : scope,
'StudentsFactory' : StudentsFactory
});
students = [{
name: 'Pedro',
age: 10
}, {
name: 'João',
age: 11
}, {
name: 'Thiago',
age: 9
}];
spyOn(StudentsFactory, 'getStudents').and.returnValue(students);
});
});
it('Should get all students', function() {
scope.students = [];
StudentsController.getStudents();
$scope.$apply();
expect(scope.students.length).toBe(3);
});
});
The problem is when I run the test, the following message is displayed:
undefined is not a constructor (evaluating
'StudentsController.getStudents()')
I looked at the whole internet trying to find a tutorial that can help me on that, but I didn't find anything, could someone help me here?
It's link to the fact that the function getStudent() is private (declared by var). Thus your test can't access it. You have to attach it to the $scope or this to be able to test it.
I generally use this in controller:
var $this = this;
$this.getStudents = function() {
...
};
There's no StudentsController.getStudents method. It should be
this.getStudents = function () { ... };
Mocked StudentsFactory.getStudents returns a plain object, while it is expected to return a promise.
$controller shouldn't be provided with real StudentsFactory service as local dependency (it is already provided with it by default):
var mockedStudentsFactory = {
getStudents: jasmine.createSpy().and.returnValue($q.resolve(students))
};
StudentsController = $controller('StudentsController', {
$scope : scope,
StudentsFactory : mockedStudentsFactory
});

Why am I getting "Incorrect injection token!" in this angular application code?

I'm trying to setup a restful API interface via AngularJS with the following code:
'use strict';
(function(angular) {
function ApiAction($resource, ResourceParameters) {
return $resource(ResourceParameters.route,
{ },
{ api_index: {
method: ResourceParameters.method,
isArray: true
}
});
return $resource(ResourceParameters.route,
{ },
{ create: {
method: ResourceParameters.method,
isArray: true
}
}
);
}
function ResourceParameters($scope) {
var factory = {};
factory.method = '';
factory.route = '';
factory.SetMethod = function(method) {
factory.method = method;
}
factory.SetRoute = function(route) {
factory.route = route;
}
return factory;
}
function superheroCtr($scope, ApiAction, ResourceParameters) {
$scope.superheroSubmit = function() {
// ApiAction.create({}, { superhero_name: $scope.superheroName, age: $scope.superheroAge });
angular.forEach($scope.superheroes, function(hero) {
// ApiAction.create({}, { superhero_name: hero.superhero_name, age: hero.age });
});
};
var heroesResources = ResourceParameters($scope).SetRoute('/api/');
var heroes = ApiAction.api_index({}, heroesResources);
$scope.superheroes = [];
heroes.$promise.then(function(data) {
angular.forEach(data, function(item) {
$scope.superheroes.push(item);
});
}, function(data) {
//if error then...
});
$scope.appendSuperheroFields = function() {
var i = $scope.superheroes.length + 1;
$scope.superheroes.push({"id": i, age: "", superhero_name: "" })
}
}
var superheroApp = angular.module('superheroApp', ['ngResource']);
superheroApp.controller('superheroCtr', ['$scope', 'ApiAction', 'ResourceParameters', superheroCtr]);
superheroApp.factory('ResourceParameters', ['$scope', ResourceParameters]);
superheroApp.factory('ApiAction', ['$resource', ResourceParameters, ApiAction]);
})(angular);
Yet, when I run it I get the following error:
Error: [$injector:itkn] Incorrect injection token! Expected service name as string, got function ResourceParameters($scope)
Why is this?
Simply you can not inject $scope OR you can not have access to $scope
inside a factory
Your problem is at this line
superheroApp.factory('ResourceParameters', ['$scope', ResourceParameters]);
You need to replace that line with
superheroApp.factory('ResourceParameters', [ResourceParameters]);
Factory
function ResourceParameters() { //<--removed $scope from here
var factory = {};
factory.method = '';
factory.route = '';
factory.SetMethod = function(method) {
factory.method = method;
}
factory.SetRoute = function(route) {
factory.route = route;
}
return factory;
}
Update
Additionally you should correct the declaration of ApiAction where ResourceParameters should be placed inside ' single qoutes
superheroApp.factory('ApiAction', ['$resource', 'ResourceParameters', ApiAction]);

AngularJS sharing data form AJAX $http request

I have the following controllers:
angular.module('app').controller('ParentCtrl', function(Service) {
var list = []
var init = function () {
Service.query().success(function() {
list = Service.getList();
});
}
});
angular.module('app').controller('ChildCtrl', function(Service) {
var list = []
var init = function () {
list = Service.getList();
}
});
angular.module('app').factory('Service', function($http) {
list = []
return {
query : function() {
$http.get('/path/to/my/api').success(function(data){
list = data
})
},
getList: function() {
return list;
}
}
});
My HTML is as follows:
<div ng-controller="ParentCtrl as parent">
<div ng-controller="ChildCtrl as child">
</div>
</div>
So basically when I receive the AJAX request I want both the controllers to get updated with the data
The best way would be to return the promise from $http.get:
angular.module('app').factory('Service', function($http) {
var promise;
return {
getList: function() {
if (promise) {
return promise;
}
promise = $http.get('/path/to/my/api');
return promise;
}
}
});
angular.module('app').controller('ParentCtrl', function(Service) {
var list = [];
var init = function () {
Service.getList().then(function(response) {
list = response.data;
});
}
});
angular.module('app').controller('ChildCtrl', function(Service) {
var list = [];
var init = function () {
Service.getList().then(function(response) {
list = response.data;
});
}
});
You can broadcast custom message to rootScope and Your controllers will get this message and handle it.
angular.module('app').controller('ParentCtrl', function($rootScope, $scope, Service) {
$scope.list = [];
$scope.$on('Service:list', function(event, data){
$scope.list = data;
});
});
angular.module('app').controller('ChildCtrl', function($rootScope, $scope, Service) {
$scope.list = [];
$scope.$on('Service:list', function(event, data){
$scope.list = data;
});
Service.query(); // run once, get in both controllers
});
angular.module('app').factory('Service', function($rootScope, $http) {
var list;
return {
query : function() {
$http.get('/path/to/my/api').success(function(data){
list = data;
$rootScope.$broadcast('Service:list', list);
})
},
getList: function() {
return list;
}
}
});
You could handle it in many ways. One simple way is to cache the promise and return it.
Example:-
angular.module('app').factory('Service', function($http, $q) {
var listPromise;
return {
getList: function() {
//If promise is already present then
return listPromise || (listPromise = $http.get('/path/to/my/api').then(function(response){
return response.data;
})
//Use the below 2 blocks (catch and finally) only if you need.
//Invalidate in case of error
.catch(function(error){
listPromise = null;
return $q.reject(error);
})
//Use finally to clean up promise only if you only need to avoid simultaneous request to the server and do not want to cache the data for ever.
.finally(function(){
listPromise = null;
}));
}
}
});
and in controller:
angular.module('app').controller('ParentCtrl', function(Service) {
var list = [];
var init = function () {
Service.getList().then(function(data) {
list = data;
});
}
});
angular.module('app').controller('ChildCtrl', function(Service) {
var list = [];
var init = function () {
Service.getList().then(function(data) {
list = data;
});
}
});
Caching a promise will make sure that it really does not matter who makes the first call and you always make the same service call to get the data and service will manage data caching via promise and prevent any duplicate calls.
Another practice is to implement a one-way data flow using flux pattern. Where you create stores that maintains data and it will make ajax call via a dispatcher and emits event to the subscribers of change event. There is an angular library (flux-angular) that can be used as well to implement this pattern. This will really help synchronize data between multiple components regardless of whether they are parent/child or siblings and regardless of who makes the first call etc..

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