Short version: how to inject an object inside Action in Play Framework?
Long version: In my project I have custom annotation action #AuthenticationRequired which loads User object from the database and puts it into context.args. It uses DAO class that implements UserDAO. Now I want to use DAO class injected into Action by Google Guice. I can use Guice and inject instances in controllers and tests, but I have difficulties injecting DAO class inside Action.
Injector is a field on GlobalSettings instance.
I tried to override GlobalSettings#onRequest() and put UserDAO instance to context.args and then retrieve it from inside AuthenticationRequired action, but it turns out that Action returned by GlobalSettings#onRequest() being called last in the chain of action used with #With and/or custom annotations, so, it is to late.
I also tried to inject DAO instance by annotating action constructor, but but it uses no-args constructor to create an instance of action.
Any ideas how can I achieve this?
For play 2.5 you can simply add #Inject on top of the constructor of Action class and inject whatever needed. Here is a snippet from my working project (I'm using Guice as DI):
public class ChannelPermissionAction extends Action<ChannelPermission> {
private final AuthorizationService authorizationService;
private final AsyncHelper asyncHelper;
#Inject
public ChannelPermissionAction(AuthorizationService authorizationService, AsyncHelper asyncHelper) {
this.authorizationService = authorizationService;
this.asyncHelper = asyncHelper;
}
...
}
You can achieve this just the same as with controllers - describe your action as (a bean in my case - i'm using spring IoC) a dependency and get it called by
public <A> A getControllerInstance(Class<A> clazz)
of Application Global object. That's all you need - you'r dependencies would be injected.
BTW. Actions need to be created with each instance so in my case I should use "prototype" scope.
Mind it while using Guice - it should have similar functionality.
Related
I'm writing helper class and inject in in _ViewImports with
#inject HtmlHelperInject.TestHelper TestHelper
And register in Startup.ConfigureServices with
services.AddTransient<TestHelper>();
How can I obtain ViewContext in this helper class? I tried injecting via controler - not working, via [ViewContext] attribute on property - not working.
As of right now (beta8) the way to do this is to implement... wait for it... ICanHasViewContext. This interface adds the following contract:
void Contextualize(ViewContext viewContext);
When injecting your custom utility MVC calls Contextualize and passes in the current ViewContext. Note: this mechanism will most likely change in future releases. If not, the name certainly will :)
Hope this helps!
I want to test methods in my controller, I know about this...
myController = new MyController();
A.CallTo(()=>myController.SomeMethodIWantToTest().Returns(someValueIAmTesting);
The problem is that inside that parameterless constructor, I call numerous methods in other assemblies that set values for private members,
public class MyController : Controller {
private ILoginBusiness loginBusiness;
private ISomethingElse somethingElse;
//... and so on...
public MyController(){
loginbusiness = ServiceFactory.GetLoginBusiness();
somethingElse = //some method in another assembly that initializes the value
//... and so on, calling methods in other assemblies that initialize the private members...
}
public ActionResult SomeMethodIWantToTest(){ }
}
So how do I isolate all those method calls in my constructor (so I'm not calling methods in those other assemblies?)
First,
myController = new MyController();
A.CallTo(()=>myController.SomeMethodIWantToTest().Returns(someValueIAmTesting);
Will result in an error, as A.CallTo only handles calls to fakes (and there should be an extra ) after …ToTest()).
Second, the general approach that is taken in this sort of situation is called Dependency Injection. Instead of having a class make all its dependencies (in your case, by calling methods from other assemblies), you have its dependencies provided to it.
Assuming you're able to start injecting dependencies, you're almost home. You're already relying on interfaces inside MyController, so then you can use FakeItEasy to supply fakes to MyController, avoiding calls to the out-of-assembly methods.
To begin with two things.
I am trying to achieve an action filter that logs when and action begins and when it end
I am well aware of the .AsActionFilter() method in Autofac 3.0 BUT...
The project that this is using is based in Orchard 1.6 which is known to be compatible with autofac 2.6.xxx. We do not want to go through a potentially lengthy process of upgrading to Autofac 3.0 at this time so the .AsActionFilter() option is not available to us.
The other option is to set the filter (which extends ActionFilterAttribute) as an attribute on our base controller (from which all other inherit btw). The problem is that the filter itself has two dependencies:
A service of our own that holds information on the context
An implementation of an ILoggingService
What I cannot find is a way to inject these into the actual property at the head of the class. Does anyone know a way in which to achieve this either through the [Attribute] line itself of some function of Autofac during registation?
The ActionFilterAttribute:
public class GRMSActionLoggingFilter : ActionFilterAttribute {
private readonly IGRMSCoreServices _grmsCoreServices;
private readonly ILoggingService _loggingService;
public GRMSActionLoggingFilter(IGRMSCoreServices grmsCoreServices, ILoggingService loggingService) {
_grmsCoreServices = grmsCoreServices;
_loggingService = loggingService;
}
public GRMSActionLoggingFilter() { }
public override void OnActionExecuting(ActionExecutingContext actionContext) {...}
public override void OnActionExecuted(ActionExecutedContext actionContext) {...}
}
Assigning the attribute to the base controller:
// This currently compiles but will fail during run time as the IGRMSCoreSerivces and ILoggingService will both be null. Need to property inject these services somehow.
[GRMSActionLoggingFilter]
Anyone have any idea to achieve this?
You cannot (easily) inject runtime values to attributes.
This is how attributes work in C# - you can only pass constant values of certain types. You can read more about it here.
In order to achieve desired functionality in Orchard you need to split your code into two components:
a marker attribute class you put on your action
an action filter class inheriting from FilterProvider and implementing IActionFilter
The way it works is that you put an attribute on some action and then use the action filter to check existence of that attribute (using filterContext.ActionDescriptor.GetCustomAttributes(...)). If an attribute exists, do your stuff.
There are lots of examples of this technique in Orchard core. Check eg. the ThemedAttribute and ThemeFilter action filter classes.
I'm new to Rhino, and wondered how to mock a local variable/object inside a method of a class I'd also be mocking. In this case I'd be doing it with an ASP.Net MVC controller & action method.
Here's what the controller looks like, simplified:
public class HomeController : Controller {
public myObjectType myMockedObject; //I want to mock this
public myNonMockedObject; //don't want to mock this
public ViewResult Index() {
//call various methods on the mocked and nonmocked members
return View();
}
}
In other words, I'd like to create a mock home controller and mock some local variables within it and their methods-- but not all of them. Is this possible using Rhino?
You can inject these through constructor parameters. Just write constructor that takes myObjectType as parameter. Within this constructor just initialize your fields.
Note1: in case to run MVC, you will need also parameterless ctro, or modify ConstructorFactory (e.g. here https://www.codeproject.com/Articles/560798/ASP-NET-MVC-Controller-Dependency-Injection-for-Be). Or just think about using some IoC container (e.g. https://www.nuget.org/packages/Unity/) that can inject whatever you want inside the controller (mock or normal class).
Note2: you should extract an interface from myObjectType class and mock that interface instead of concrete class (Rhino handles that better).
Note3: I am usually trying to put all the logic (and test that separately) outside of controller since it is quite tough to test the controller (you need to initialize a lot of stuff there what involves another mocking).
Background
I am trying to move business logic out from the controllers into their own services.
Controller
public class AccountController : Controller
{
private readonly IAccountService _accountService;
public AccountController(IAccountService accountService)
{
_accountService = accountService;
}
....
}
I'm using Unity to inject dependencies. I'd like to use the Url.GenerateUrl() helper method within the implementation of IAccountService but Url is a property against the controller.
I looked at the MVC source to see how this is done but it requires me to access the RequestContext from outside of the controller, and I don't know how to do that.
Question
How do I access the RequestContext from outside the controller? If that won't solve my problem, how do I solve the problem given my setup?
This might not be quite right because I'm unable to test it at the moment, but I think that you can do something like this in .NET 4+:
using System.Web;
using System.Web.Mvc;
// ...
var helper = new UrlHelper(HttpContext.Current.Request.RequestContext);
string url = helper.GenerateUrl(/* ... */);
It might make more sense to pass the context from the controller to your IAccountService implementation rather than grabbing it directly from HttpContext.Current.
However i'd like to use the Url.GenerateUrl helper methods within my implementation of IAccountService
Simply pass this information as parameter. Example:
public ActionResult Index()
{
var someUrl = Url.Action("about");
_accountService.Foo(someUrl);
}
Now you no longer need UrlHelper inside your service classes. Everything that needs interacting with MVC infrastructure shouldn't be placed in your service classes. They shouldn't depend on any Request, Response, Session, ... It's the controller's responsibility to work with those objects and glue them together with your service classes.