Angular JS Initialize service with different parameter dynamically - javascript

I have an app that when you select a project, it goes into the project section where it needs to load all the information and data about a project asynchronously.
I wanted to store all the data in a singleton service so I can access the data in all the project's subsections(project header, project footer, main menu, etc)
If user clicks a different project, it will need to re-initialize with different URL parameter (in this case, project_id).
app.factory('ProjectService', function($http, project_id) {
var SERVICE = {
async: function() {
var promise = $http.get('SOME URL' + project_id).then(function(response) {
return response.data;
});
return promise;
}
};
return SERVICE;
});
What is the best way to achieve this and how can I reinitialize the service with different URL parameters when user clicks a button?

Check working demo: JSFiddle
First of all, using a factory may be more suitable for your case.
You need to play with the deferred/promise manually. If the requested id is already loaded, resolve the deferred object immediately. Otherwise, send a HTTP request (in the demo I just used an public API providing fake data) and fetch the project information.
app.factory('ProjectFactory', ['$http', '$q', function ($http, $q) {
var myProject;
return {
project: function (id) {
var deferred = $q.defer();
// If the requested id is fetched already, just resolve
if (!id || (myProject && myProject.id === id)) {
console.log('get from cache');
deferred.resolve(myProject);
} else {
console.log('sending request...');
$http.get('http://jsonplaceholder.typicode.com/posts/' + id).success(function (response) {
myProject = response;
deferred.resolve(myProject);
}).error(function (response) {
deferred.reject(response);
});
}
return deferred.promise;
}
};
}]);
To use this factory:
app.controller('JoyCtrl', ['$scope', '$timeout', 'ProjectFactory', function ($scope, $timeout, ProjectFactory) {
ProjectFactory.project(1).then(function (project) {
$scope.project = project;
ProjectFactory.project(1).then(function (project) {
});
}, function (reason) {
console.log('Failed: ' + reason);
});
}]);
For your reference: $http, $q

Related

How to get data from an API in a Angular Service and store it to be used by anyone in the future

This is more of a writing clean code/ optimizing existing code.
I am writing my Angular Services to fetch data from backend like this
angular.module('myApp').service('Auth', ['$http', '$q', 'Config', function($http, $q, Config) {
this.getUser = function() {
return $http.get(Config.apiurl + '/auth/user')
.then(function(response) {
return response.data;
}, function(error) {
return $q.reject(error.data);
});
};
}]);
Now in this, I am calling getUser function n number of times from the Database.
Now the question is, is it okay to call this service to get n times redundant data or I should it be saved somewhere say rootscope to be accessed later? Or storing in root scope would be bad practice and I should consider some other option or nothing at all?
Would like to get some views on Angular Community here.
Here is a sample example on how to use factory for sharing data across the application.
Lets create a factory which can be used in entire application across all controllers to store data and access them.
Advantages with factory is you can create objects in it and intialise them any where in the controllers or we can set the defult values by intialising them in the factory itself.
Factory
app.factory('SharedData',['$http','$rootScope',function($http,$rootScope){
var SharedData = {}; // create factory object...
SharedData.appName ='My App';
return SharedData;
}]);
Service
app.service('Auth', ['$http', '$q', 'SharedData', function($http, $q,SharedData) {
this.getUser = function() {
return $http.get('user.json')
.then(function(response) {
this.user = response.data;
SharedData.userData = this.user; // inject in the service and create a object in factory ob ject to store user data..
return response.data;
}, function(error) {
return $q.reject(error.data);
});
};
}]);
Controller
var app = angular.module("app", []);
app.controller("testController", ["$scope",'SharedData','Auth',
function($scope,SharedData,Auth) {
$scope.user ={};
// do a service call via service and check the shared data which is factory object ...
var user = Auth.getUser().then(function(res){
console.log(SharedData);
$scope.user = SharedData.userData;// assigning to scope.
});
}]);
In HTML
<body ng-app='app'>
<div class="media-list" ng-controller="testController">
<pre> {{user | json}}</pre>
</div>
</body>
Instead of rootScope just use a local variable of user in your service that can be accessed from anywhere in your code and so you doesn't have to call the api every time.
angular.module('metaiotAdmin').service('Auth', ['$http', '$q', 'Config', function($http, $q, Config) {
this.getUser = function() {
if(this.user){
return this.user;
}
else{
return $http.get(Config.apiurl + '/auth/user')
.then(function(response) {
this.user = response.data;
return response.data;
}, function(error) {
return $q.reject(error.data);
});
}
};
}]);
Hope it helps.
You don't have to, $http already caches your request for you, if the same request is applied in case you set the cache config option to true.
$http.get('/hello', { cache: true})
.then(onResponse)
or you can either set it for every request, by using either an interceptor or override the http instance in the $httpProvider, to apply the effect for every http request.
app.module('app.module')
factory('MyHttpInterceptor', function() {
return {
request : function(config) {
config.cache = true;
return config;
},
// rest of implementation of the interceptor
}
});
app.module('app.module')
.config(['$httpProvider', function($httpProvider) {
$httpProvider.interceptors.push('MyHttpInterceptor');
// ... rest of the configuration
}]);
Or :
app.module('app.module')
.config(['$httpProvider', function($httpProvider) {
$httpProvider.defaults.cache = true;
// ...
}]);
see :
Angular doc for caching

AngularJS call method inside $routeProvider

I'm newer in AngularJS. So I have a simple question, but I can't find answer. I have code:
angular.module('app', ['app.controllers', 'ngRoute']).
config(['$routeProvider', function ($routeProvider) {
$routeProvider.when('/users', {templateUrl: '../pages/list.html', controller: 'UserListCtrl'}).
when('/user-details/:login', {templateUrl: '../pages/form.html', controller: 'UserCtrl' /* and here I need to call userDetails(login) from UserCtrl */}).
otherwise({redirectTo: '/users'});;
}
]);
app.controller('UserCtrl', function ($scope, $http, $location) {
$scope.userDetails = function (login) {
$http.get(url + login).success(function (data) {
$scope.user = data[0];
console.log('tst');
}).error(errorCallback);
};
$scope.createUser = function (user) {
$http.post(url, user).success(function (data) {
$location.path('/users');
}).error(errorCallback);
};
});
My problem is: I don't know how to call specific method of controller when routing matches. I need to call method and give to it parameter :login from routing. How to solve this?
Thanks for your answers
If I understand correctly, you are re-using the same controller for two parts of the view (or for two views), one for creating a user and one for fetching the details of the current user.
Since these two aspects are totally different, it is not advisable to use the same controller for both. The controllers should be different and any common or re-usable functionality should be shared through a service.
In any case, code that makes calls to the backend should not be placed inside controllers, but into services. E.g.:
app.service('UserSrv', function ($http) {
var url = '...';
this.userDetails = function (login) {
return $http.get(url + login);
};
this.createUser = function (user) {
return $http.post(url, user);
};
});
app.controller('UserCtrl', function ($scope, UserSrv) {
var login = '...';
var errorCallback = ...;
// Fetch user details upon initialiation
UserSrv.userDetails(login).success(function (data) {
$scope.user = data[0];
}).error(errorCallback);
});
app.controller('NewUserCtrl', function ($location, $scope, UserSrv) {
var errorCallback = ...;
$scope.createUser = function (user) {
UserSrv.createUser(user).success(function (data) {
$location.path('/users');
}).error(errorCallback);
};
});
You could, also, use $routeProvider's resolve property to "preload" the user's details and pass it to the UserCtrl as an argument.

Angular JS Method GET inside RUN after CONFIG

I need to do a request inside the RUN method to retrieve de user data from an api.
The first page (home), depends on the user data.
This is the sequence of dispatchs in my console:
CONFIG
RUN
INIT GET USER DATA
SIDEBAR
HOME
SUCCESS GET USER DATA
My problem is, i need to wait user data before call sidebar and home (controller and view) and i don't know how can i do this.
UPDATE
I have this until now:
MY CONFIG:
extranet.config(['$httpProvider', '$routeProvider', function ($httpProvider, $routeProvider) {
// My ROUTE CONFIG
console.log('CONFIG');
}]);
My RUN:
extranet.run(function($rootScope, $location, $http, Cookie, Auth, Session) {
console.log('RUN');
var token = Cookie.get('token');
// The login is done
var success = function (data) {
Session.create(data);
console.log('USER DATA SUCCESS');
};
var error = function () {
$location.path('/login');
};
// GET USER DATA
Auth.isAuthenticated().success(success).error(error);
});
MY CONTROLLER MAIN:
extranet.controller('MainCtrl', function ($scope, $location) {
console.log('MAIN CONTROLLER');
});
By using resolver
extranet.config(['$httpProvider', '$routeProvider', function ($httpProvider, $routeProvider) {
// My ROUTE CONFIG
$routeProvider.when('/', {
templateUrl: "/app/templates/sidebar.html",
controller: "siderbarController",
title: "EventList",
resolve: {
events: function ($q, Cookie,Session) {
var deffered = $q.defer();
Cookie.get('token').$promise
.then(function (events) {
Session.create(data);
console.log('USER DATA SUCCESS');
deffered.resolve(events);
}, function (status) {
deffered.reject(status);
});
return deffered.promise;
}
}
}]);
I hope you get some idea.
If you are using AngularJS methods for server requests you will get a promise. A promise gets resolved as soon as the response is recieved. All defined callbacks "wait" until the resolve.
Naive solution
So, you will use $http or even $resource if you have a REST-like backend:
var promise = $http.get(userDataUrl, params)
$rootScope.userDataPromise = promise;
After that you can use that promise whereever you need the data:
$rootScope.userDataPromise.then(myCallback)
Better solution
Using $rootScope for that purpose is not an elegant solution though. You should encapsulate the Userdata stuff in a service and inject it whereever you need it.
app.factory('UserData', ['$http',
function($http) {
var fetch = function() {
return $http.get(userDataUrl, params)
};
return {
fetch: fetch
};
}
]);
Now you can use that service in other modules:
app.controller('MainCtrl', ['$scope', 'UserService',
function ($scope, UserService) {
var update = function(response) {
$scope.userData = response.userData;
}
var promise = UserService.fetch();
promise.then(update)
}
);

Angular controller promises and testing

Im writing some unit tests for my controller which uses promises.
Basically this:
UserService.getUser($routeParams.contactId).then(function (data) {
$scope.$apply(function () {
$scope.contacts = data;
});
});
I have mocked my UserService. This is my unit test:
beforeEach(inject(function ($rootScope, $controller, $q, $routeParams) {
$routeParams.contactId = contactId;
window.localStorage.clear();
UserService = {
getUser: function () {
def = $q.defer();
return def.promise;
}
};
spyOn(UserService, 'getUser').andCallThrough();
scope = $rootScope.$new();
ctrl = $controller('ContactDetailController', {
$scope: scope,
UserService:UserService
});
}));
it('should return 1 contact', function () {
expect(scope.contacts).not.toBeDefined();
def.resolve(contact);
scope.$apply();
expect(scope.contacts.surname).toEqual('NAME');
expect(scope.contacts.email).toEqual('EMAIL');
});
This give me the following error:
Error: [$rootScope:inprog] $digest already in progress
Now removing the $scope.$apply in the controller causes the test to pass, like this:
UserService.getUser($routeParams.contactId).then(function (data) {
$scope.contacts = data;
});
However this breaks functionality of my controller... So what should I do here?
Thanks for the replies, the $apply is not happening in the UserService. It's in the controller. Like this:
EDIT:
The $apply is happening in the controller like this.
appController.controller('ContactDetailController', function ($scope, $routeParams, UserService) {
UserService.getUser($routeParams.contactId).then(function (data) {
$scope.$apply(function () {
$scope.contacts = data;
});
});
Real UserService:
function getUser(user) {
if (user === undefined) {
user = getUserId();
}
var deferred = Q.defer();
$http({
method: 'GET',
url: BASE_URL + '/users/' + user
}).success(function (user) {
deferred.resolve(user);
});
return deferred.promise;
}
There are a couple of issues in your UserService.
You're using Q, rather than $q. Hard to know exactly what effect this has, other than it's not typical when using Angular and might have affects with regards to exactly when then callbacks run.
You're actually creating a promise in getUser when you don't really need to (can be seen as an anti-pattern). The success function of the promise returned from $http promise I think is often more trouble than it's worth. In my experience, usually better to just use the standard then function, as then you can return a post-processed value for it and use standard promise chaining:
function getUser(user) {
if (user === undefined) {
user = getUserId();
}
return $http({
method: 'GET',
url: BASE_URL + '/users/' + user
}).then(function(response) {
return response.data;
});
}
Once the above is changed, the controller code can be changed to
UserService.getUser($routeParams.contactId).then(function (data) {
$scope.contacts = data;
});
Then in the test, after resolving the promise call $apply.
def.resolve(contact);
scope.$apply();

In an Angular, how would I get bootstrap data from the server before launch?

A bit of info. I'm working on a single page app, but am attempting to make it just an HTML file, rather than an actual dynamic page that contains all the bootstrap information in it. I'm also hoping to, when the app boots (or perhaps prior to), check to see if the current session is 'logged in', and if not then direct the hash to the 'login'.
I'm new to Angular, and am having a difficult time figuring out how to program out this flow. So, in essence..
HTML page loaded with 'deferred' bootstrap
Hit URL to get login status
If status is 'not logged in', direct to #/login
Start app
Any pointers on where #2 and #3 would live? In my 'easy world' I'd just use jquery to grab that data, and then call the angular.resumeBootstrap([appname]). But, as I'm trying to actually learn Angular rather than just hack around the parts I don't understand, I'd like to know what would be used in this place. I was looking at providers, but I'm not sure that's what I need.
Thanks!
EDIT
Based on #Mik378's answer, I've updated my code to the following as a test. It works to a point, but as the 'get' is async, it allows the application to continue loading whatever it was before then shooting off the status results..
var app = angular.module('ping', [
'ngRoute',
'ping.controllers'
]).provider('security', function() {
this.$get = ['$http', function($http) {
var service = {
getLoginStatus: function () {
if (service.isAuthenticated())
return $q.when(service.currentUser);
else
return $http.get('/login/status').then(function (response) {
console.log(response);
service.loggedIn = response.data.loggedIn;
console.log(service);
return service.currentUser;
});
},
isAuthenticated: function () {
return !!service.loggedIn;
}
};
return service;
}];
}).run(['security', function(security) {
return security.getLoginStatus().then(function () {
if(!security.isAuthenticated()) {
console.log("BADNESS");
} else {
console.log("GOODNESS");
}
});
}]);
My hope was that this could somehow be completed prior to the first controller booting up so that it wasn't loading (or attempting to load) things that weren't even cleared for access yet.
EDIT #2
I started looking into the 'resolve' property in the router, and #Mik378 verified what I was looking at. My final code that is (currently) working how I want it is as follows (appologies about the super long code block)
angular.module('ping.controllers', [])
.controller('Dashboard', ['$scope', function($scope) {
console.log('dashboard')
}])
.controller('Login', ['$scope', function($scope) {
console.log('login')
}]);
var app = angular.module('ping', [
'ngRoute',
'ping.controllers'
]).run(['$rootScope', '$location', function($root, $location) {
$root.$on("$routeChangeError", function (event, current, previous, rejection) {
switch(rejection) {
case "not logged in":
$location.path("/login"); //<-- NOTE #1
break;
}
});
}]);
app.provider('loginSecurity', function() {
this.$get = ['$http', '$q', function($http, $q) {
var service = {
defer: $q.defer, //<-- NOTE #2
requireAuth: function() { //<-- NOTE #3
var deferred = service.defer();
service.getLoginStatus().then(function() {
if (!service.isAuthenticated()) {
deferred.reject("not logged in")
} else {
deferred.resolve("Auth OK")
}
});
return deferred.promise;
},
getLoginStatus: function() {
if (service.isAuthenticated()) {
return $q.when(service.currentUser);
} else {
return $http.get('/login/status').then(function(response) {
console.log(response);
service.loggedIn = response.data.loggedIn;
console.log(service);
return service.currentUser;
});
}
},
isAuthenticated: function() {
return !!service.loggedIn;
}
};
return service;
}
];
});
app.config(['$routeProvider', function($routeProvider) {
console.log('Routing loading');
$routeProvider.when('/', {
templateUrl: 'static/scripts/dashboard/template.html',
controller: 'Dashboard',
resolve: {'loginSecurity': function (loginSecurity) {
return loginSecurity.requireAuth(); //<- NOTE #4
}}
});
$routeProvider.when('/login', {
templateUrl: 'static/scripts/login/template.html',
controller: 'Login'
});
$routeProvider.otherwise({redirectTo: '/404'});
}]);
Notes:
This section hooks into routing failures. In the case of a "no login", I wanted to catch the failure and pop the person over to the login page.
I can't get access to the $q inside of the requireAuth function, so I grabbed a reference to it. Perhaps a better way of doing this exists?
This function wraps up the other two - it uses the promise returned from getLoginStatus, but returns its own promise that will be rejected if the end result from the getLoginStatus winds up with the user not being logged in. Sort of a round-about way of doing it.
This returns #3's promise, which is used by the $routeProvider.. so if it fails, the routing fails and you end up catching it at #1.
Whew. I think that's enough for a day. Time for a beer.
No need to use a deferred bootstrap for your case:
angular.module('app').run(['security', '$location', function(security) {
// Get the current user when the application starts
// (in case they are still logged in from a previous session)
security.requestCurrentUser().then(function(){
if(!security.isAuthenticated())
$location.path('yourPathToLoginPage')
}; //service returning the current user, if already logged in
}]);
this method requestCurrentUser would be the following:
requestCurrentUser: function () {
if (service.isAuthenticated())
return $q.when(service.currentUser);
else
return $http.get('/api/current-user').then(function (response) {
service.currentUser = response.data.user;
return service.currentUser;
});
}
and inside security service again:
isAuthenticated: function () {
return !!service.currentUser;
}
Note the run method of the module => As soon as the application runs, this service is called.
-- UPDATE --
To prevent any controller to be initialized before the promise provided by requestCurrentUser is resolved, a better solution, as evoked in the comments below, is to use the resolve route property .

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