I'm trying to decorate a service with another method. The problem is that method uses $http which I can't inject into the angular.config block because it hasn't been initialised yet.
I thought I could get around this by using $injector as this would only run when the method I add gets called, but this results in the error:
Error: [$injector:unpr] Unknown provider: $http
Here's an example of what I am trying to do:
angular.module('someModule', [])
.config(($provide, $injector)->
$provide.decorator('someService', ($delegate)->
$delegate.newMethod = ()->
$http = $injector.get('$http')
$http.get('someURL')
return $delegate
)
)
Later on, only when I call someService.newMethod() do I get the error mentioned above.
Is there any way to do what I'm trying to do?
Apparently the $injector needs to be injected to the decorator as well, so this will fix it:
angular.module('someModule', [])
.config(($provide, $injector)->
$provide.decorator('someService', ($delegate, $injector)->
$delegate.newMethod = ()->
$http = $injector.get('$http')
$http.get('someURL')
return $delegate
)
)
Related
Snippet 1 does not work. I get Error: [$injector:unpr] Unknown provider: $q
/* Snippet 1*/
var mApp = angular.module('MyApp',[]);
mApp.provider('authProvider', ['$q', function($q) {
this.$get = function(){
authProvider = {};
authProvider.Title = function(){
var deferred = $q.defer();
deferred.resolve("promise resolved");
return deferred.promise;
}
return authProvider;
}
}]);
However, Snippet 2 works. I am confused why that is ? All the factory sample codes i have read, inject the dependency in the first line such as
.factory('MyFactory',[$q,function($q) {}]);
Why doesnt that style work in the provider code above ? Also, why are we injecting $q below in the GET declaration but not further down in the TITLE declaration.
/* Snippet 2*/
mApp.provider('authProvider', function() {
this.$get = function($q){
authProvider = {};
authProvider.Title = function(){
var deferred = $q.defer();
deferred.resolve("promise resolved");
return deferred.promise;
}
return authProvider;
}
});
Please help!!!
(The code doesn't do anything right now. I am just trying to learn syntax)
you can't do direct DI in provider , when you are using provider you have to inject your component in $get .
Reason you cannot inject dependency into the provider directly is that the provider runs during the module loading phase whereas the $get is run when instantiating the service you are providing.
You can not use any service during the loading/configuration phase of your modules.
All the factory sample codes i have read, inject the dependency in the first line such as .factory('MyFactory',[$q,function($q) {}]); Why doesn't that style work in the provider code above ?
This graphic has always helped me understand the difference between a provider and a factory:
source: simplygoodcode.com
The factory function is the $get function of the provider. Before injection, the provider constuction function can configure the $get function. The $get function is where injection happens.
The provider construction function isn't injectable. That's why you get that error. The $get function is injectable and that is the function that you specify with factory. factory is just syntactic sugar for creating a provider with an empty constructor function.
See Also
Confused about Service vs Factory — this answer
When making use of a service in a controller test do you need to initialize the service in the same way you would the controller? By this I mean do you need to pass it its own dependencies?
For example I can initialize my controller like so:
// Instantiate the controller
searchController = $controller( 'VisibilitySearchController',{
$scope: scope,
dataService: dataService
});
}));
so do I need to initialize the service according to the components it needs like $http, $resource etc as well as make spyOn calls on its functions? Or is this/should this be sufficient? (Note - my tests fail when I do the following )
// Instantiate the dataService
dataService = $injector.get( 'dataService' );
it throws this error:
* Error: [$injector:unpr] Unknown provider: $resourceProvider <- $resource <- dataService
The relevant part of the service:
myAppServices.factory('dataService', ['$http', '$resource', 'authService', 'messageService', function ($http, $resource, authService, messageService) {
}
Side note
Note - we are using Maven as our build tool and only make use of Jasmine at this point - trying to bring Karma in as our test-runner as a Maven plugin.
You must provide all the dependencies but you can mock them. This can be done by jasmine like this for example:
var mockedDataService = jasmine.createSpyObj('dataService', ['getData', 'getOtherData']);
And then you inject this mocked service to $provider:
beforeEach(function () {
module(function ($provide) {
$provide.value('dataService', mockedDataService );
});
}
Instance of this mocked service can be retrieved like this then:
inject(function (dataService) {
var dataServiceInstance = dataService;
});
This will provider mocked dataService anytime it is needed. However if you need fully functional dataService you must instantiate it but always you can mock any of its dependecies.
While you can inject dependencies into the controller manually you don't need to do it as long as you have loaded the module the service belongs to.
In your case it looks like you have not loaded the ngResource module.
If you add beforeEach(module('ngResource')) to your test (and make sure the actual script file it lives in is included in Jasmine's fileset) you should not need to inject it manually.
Note that you do not need to load angular core services like $http, but since $resource is not part of core it needs to be loaded like this.
Injecting dependencies manually is mostly useful if you want to provide a mock implementation.
When I try inject $http into an overridden factory I get the error:
Uncaught Error: [$injector:cdep] Circular dependency found: $http <-
$exceptionHandler <- $rootScope
AngularModule.factory('$exceptionHandler', function ($http) {
any ideas how to resolve? if I inject using [], $http is undefined
edit__________________
as per an answer below I tried:
MyModule.config(function($provide, $http) {
$provide.decorator("$exceptionHandler", function($delegate) {
return function(exception, cause) {..
but I still get the circular error:
Uncaught Error: [$injector:cdep] Circular dependency found: $http <-
$exceptionHandler <- $rootScope
Inject the $injector and then get the $http service from there. Something like this:
AngularModule.factory('$exceptionHandler', function ($injector) {
var $http = $injector.get("$http");
See https://groups.google.com/forum/#!topic/angular/lbFY_14ZtnU/discussion
However, this will completely override the $exceptionHandler functionality provided by Angular. If you just want to add the server-side log to the existing functionality, see this question about augmenting $exceptionHandler functionality.
I'm using this solution, because of circular dependency issues with rootScope:
angular
.module('facilityLog')
.provider('$exceptionHandler', function() {
"use strict";
this.$get = function($injector) {
function exceptionHandler(exception, cause) {
// This is the part where you get the instance of $http in your case
var $rootScope = $injector.get('$rootScope');
//...
}
return exceptionHandler;
}});
So if you request the instance inside the exceptionHandler-Function you will not get the circular dependency-error.
I used the following to solve this. Note how the array notation is used to make this minification safe.
Note also, that I am completely overriding the $esceptionHandler and using my own service to replace it.
angular
.module('app')
.factory('$exceptionHandler', $exceptionHandler);
$exceptionHandler.$inject = ['$injector', 'exceptionLoggingService'];
function $exceptionHandler($injector, exceptionLoggingService)
{
return function(exception, cause)
{
exceptionLoggingService.http = exceptionLoggingService.http || $injector.get('$http');
exceptionLoggingService.error(exception, cause);
};
}
Im having problem with injections.
app.js
angular.module('Help', []);
var app = angular.module('app', [
'restangular'
,'Help'
]);
app.$inject = ['RestangularProvider'];
app.config(
function(RestangularProvider) {
RestangularProvider.setBaseUrl('http://localhost:8080/api');
}
)
help.js
function HelpCtrl($rootScope, $scope, Restangular){
Restangular.one('questions').getList();
}
HelpCtrl.$inject = ['$scope', '$rootScope','Restangular']; //"TAG1"
angular.module('Help').controller("HelpCtrl", HelpCtrl);
I get the following error:
Uncaught TypeError: Object [object Object] has no method 'one'
If I remove line TAG1, everything works. However I need to inject it the right way. What is the problem here?
The injector is used to help AngularJS know the order of parameters given to the function in case the variable name change (e.g. after minimizing your JavaScript).
In your case, you've switched up the order of your injector parameters and the method signature, meaning that AngularJS will think that $scope is $rootScope and vice versa.
Either remove your $inject or make sure the parameters are in the same order in both your method signature and in your injection array.
I have been looking for a way to get services on initialization of my angular-js application, but could not find how to get it to work. In my case I want to get the $location service to observe the url.
Looking around, I found the services can be retrieved from the injector. To get the injector, I bootstrapped my application like this:
var angularApp = angular.module("MyApp", []);
var angularInjector = angular.injector(["MyApp", "ng"]);
angularApp.run(initializeAngularApp);
initializeAngularApp()
{
var location = angularInjector.get("$location");
}
This throws an Error:
Unknown provider: $rootElementProvider <- $rootElement <- $location
My understanding is that initializeAngularApp() should get called once the injector is done initializing. But judging from the error I get, it would not be the case.
What is the best way to get the services from the injector when my application initializes?
I found my answer and I did not need to instantiate the injector myself to get the service.
Services are injectable in the run() function, so doing:
angularApp.run(intializeAngularApp);
with
initializeAngularApp($rootScope, $location)
{
$rootScope.location = $location;
$rootScope.$watch("location.url()", function () { alert("url changed"); });
}
works.