For a couple of my controllers I have a base class which implements the common actions.
e.g.
- BaseAccountController has a login action
- PublicAccountController inherits from BaseAccountController and implements further actions
- CorporateAccountController inherits from BaseAccountController and implements further actions
This gives the following routes:
- BaseAccount/Login
- PublicAccount/Login
- CorporateAccount/Login
What is the standard way to remove the route BaseAccount/Login as this is not desired. I'm hoping for an attribute on the controller :)
you can use the following custom attribute for your Base controllers:
[AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = false)]
public class ClosedAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
filterContext.Result = new HttpStatusCodeResult(404);
}
}
You'll receive 404 for your Base controllers routes - BaseAccount/Login. But please be sure that Inherited property is false (as in example).
Example of using:
[Closed]
public class BaseAccountController : Controller
{
...
}
you can read more (if needed) about custom action filters here - http://www.asp.net/mvc/tutorials/older-versions/controllers-and-routing/understanding-action-filters-cs
If the BaseAccountController has only login action then you can mark it as abstract.
Related
I wish to create an object per http request within an ActionFilter and pass this object to the controller. So far I have tried Request.Properties[] like the following
public class DbReadonlyAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(HttpActionContext actionContext)
{
actionContext.Request.Properties["CustomObjectKey"] = new MyClass();
And I have also tried to assign the new object direct to a ControllerBase class.
public class DbReadonlyAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(HttpActionContext actionContext)
{
var controller = (MyControllerBase) actionContext.ControllerContext.Controller;
controller.StorageContextFactory = new MyClass();
The problem is that neither technique delivers an instance of MyClass to the controller because the new Property["CustomObjectKey"] is lost in the Webapi pipeline by the time a controller method is invoked.
The controller is re-instantiated by the webapi pipeline after the call to action filter OnActionExecuting().
Break points confirm the Webapi pipeline schedules the following event flow during a single http request.
constructor MyControllerBase()
MyAuthenticationFilter
Filter OnActionExecuting()
constructor MyControllerBase()
MyController.MethodA()
The double instantiation of MyControler is odd, but right now I am looking for any technique to pass a newly created object from an action filter to a controller.
Edit-1: The MyAuthorizationFilter mentioned in v1 of this question is actually an Authentication filter. Still investigating.
Solution: The bug was in another filter. After I removed my authentication filter the problem reported in this question went away.
You will have to use .add method Request.Properties collection.
public class DbReadonlyAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(HttpActionContext actionContext)
{
actionContext.Request.Properties.Add(new KeyValuePair<string, object>("CustomObjectKey", new MyClass()));
You can retrieve this value from your api controller.
object _customObject= null;
if (Request.Properties.TryGetValue("CustomObjectKey", out _customObjectKey))
{
MyClass myObject = (MyClass)_customObject;
}
Another way to pass variable from ActionFilter.OnActionExecuting() to an ApiController:
public class CustomFilterAttribute : System.Web.Http.Filters.ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext actionContext)
{
actionContext.ControllerContext.RequestContext.RouteData.Values["CustomValue"] = "CustomValue";
}
}
Pay attention to use ActionFilterAttribute for Web API :
System.Web.Http.Filters.ActionFilterAttribute
Not for MVC classic :
System.Web.Mvc.ActionFilterAttribute
Using:
[CustomFilter]
public class SomeController : ApiController
{
string customValue = RequestContext.RouteData.Values.ToDictionary(x => x.Key, y => y.Value)["user_id"].ToString();
//...
}
I am playing around with the idea of having a base controller that uses a generic repository to provide the basic CRUD methods for my API controllers so that I don't have to duplicate the same basic code in each new controller. But am running into problems with the routing attribute being recognized when it's in the base controller. To show exactly what the problem I'm having I've created a really simple WebAPI controller.
When I have a Get method in the main Controller and it inherits from the ApiController directly I don't have any problems and this works as expected.
[RoutePrefix("admin/test")]
public class TestController : ApiController
{
[Route("{id:int:min(1)}")]
public string Get(int id)
{
return "Success";
}
}
When I move the Get method into a base controller it is returning the contents of the 404 page.
[RoutePrefix("admin/test")]
public class TestController : TestBaseController
{
}
public class TestBaseController : ApiController
{
[Route("{id:int:min(1)}")]
public string Get(int id)
{
return "Success";
}
}
Some more interesting notes:
I can access the action at GET /Test/1. So it is finding it based on the default route still.
When I try to access POST /admin/test, it returns the following JSON
{
"Message":"No HTTP resource was found that matches the request URI 'http://test.com/admin/test'.",
"MessageDetail":"No type was found that matches the controller named 'admin'."
}
Does anyone know of a way to get the routing to work with attributes from a base controller?
Attribute routes cannot be inherited. This was a deliberate design decision. We didn't feel right and didn't see valid scenarios where it would make sense to inherit them.
Could you give a more realistic scenario as to where you would want to use this?
[Update(3/24/2014)]
In the upcoming 5.2 release of MVC Web API, there is going to be an extensibility point called System.Web.Http.Routing.IDirectRouteProvider through which you can enable the inheritance scenario that you are looking for here. You could try this yourself using the latest night builds(documentation on how to use night builds is here)
[Update(7/31/2014)]
Example of how this can be done in Web API 2.2 release:
config.MapHttpAttributeRoutes(new CustomDirectRouteProvider());
//---------
public class CustomDirectRouteProvider : DefaultDirectRouteProvider
{
protected override IReadOnlyList<IDirectRouteFactory>
GetActionRouteFactories(HttpActionDescriptor actionDescriptor)
{
// inherit route attributes decorated on base class controller's actions
return actionDescriptor.GetCustomAttributes<IDirectRouteFactory>
(inherit: true);
}
}
Using Web API 2.2, you can:
public class BaseController : ApiController
{
[Route("{id:int}")]
public string Get(int id)
{
return "Success:" + id;
}
}
[RoutePrefix("api/values")]
public class ValuesController : BaseController
{
}
config.MapHttpAttributeRoutes(new CustomDirectRouteProvider());
public class CustomDirectRouteProvider : DefaultDirectRouteProvider
{
protected override IReadOnlyList<IDirectRouteFactory>
GetActionRouteFactories(HttpActionDescriptor actionDescriptor)
{
return actionDescriptor.GetCustomAttributes<IDirectRouteFactory>
(inherit: true);
}
}
as outlined here: http://www.asp.net/web-api/overview/releases/whats-new-in-aspnet-web-api-22
Got it.
[Route("api/baseuploader/{action}")]
public abstract class BaseUploaderController : ApiController
{
[HttpGet]
public string UploadFile()
{
return "UploadFile";
}
}
[Route("api/values/{action}")]
public class ValuesController : BaseUploaderController
{
[HttpGet]
public string Get(int id)
{
return "value";
}
}
One caveat here is that the route action paramter must be the same as the action name. I could not find a way to get around that. (You cannot rename the route with a RouteAttribute)
How to display a default page like Maintenance page for all the views if a web.config key is set to true?
If the key is false, then show the regular views.
Plz note, I don't want to repeat the code in each controller and am looking for a common place, like _ViewStart or _Layout page where this can be defined.
Thanks.
You could create your own ActionFilterAttribute and base Controller, which gives you access to OnActionExecuting. You could then test if the Web.Config value is set (perhaps loading it into an Application variable when you first start your Web app) and if it is set, setting the Controller and Action attributes to your maintenance page. Then all of your controllers, instead of inheriting from the standard Controller would inherit from your controller instead, except for the Maintenance controller which could still inherit from the normal Controller.
For instance:
[RedirectToMaintenancePage]
public class MyController : Controller
{
}
And for a typical controller:
public class SampleController : MyController
{
... Your actions ...
}
Then create a class called RedirectToMaintenancePageAttribute.cs:
public class RedirectToMaintenancePageAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
If Web.config says to go to Maintenance page then...
{
filterContext.Result = RedirectToRouteResult("route name") // Or some other redirect
return;
}
// else
base.OnActionExecuting(filterContext);
}
}
This is all off the top of my head, but I think it should work, and if it doesn't hopefully it'll give you some ideas.
When a view model is created you can populate the options (e.g. used in a dropdown list) into a setter property of the view model.
The problem is that when that view model is later passed as a parameter (by the framework!) into an action method, those property values has not become automagically
repopulated, so if you need to redisplay the form because of validation errors, you need to repopulate those options again.
One potential solution, which I am asking for specifically in this question, is how to make the MVC framework instantiate the view model with constructor injection, which would provide the view model constructor with an implementation of some kind of data access object (e.g. a repository) that can be used for retrieving the options when they are requested by the view (e.g. in the helper method "DropDownListFor") ?
I think the solution might have something to do with implementations of IModelBinderProvider or IModelBinder but after having experimented with these things from example code snippets here and there on the net, I am still looking for a completely working example, with downloadable executable code without any missing piece of how putting all things together.
If you are looking for some alternative discussion about how to populate a select list, e.g. with "Dependecy Lookup" instead of "Dependecy Injection" you may want to check out the following discussion:
Best way to populate SelectList for ViewModel on GET/POST
Best way to populate SelectList for ViewModel on GET/POST
Some days ago I wrote the following follow-up-question in that thread about the "Dependecy Injection" I am now looking for in this thread:
https://stackoverflow.com/a/8674525/310457
(which provides a code example about the problem I am looking for a solution of)
But instead of hoping that someone will find that old thread with a less specific title, I have created this new question with a more specific subject about what I am looking for.
And I will also provide a link from that thread into this new question for anyone that want to follow-up regarding this specific solution I am looking for.
I'm assuming you want to have your ViewModels automatically injected with something via their Constructor - for example some kind of configuration object that the View will use to determine what to show. I'm also assuming that this approach is causing a "No parameterless constructor defined for this object" error when MVC tries to automatically create and bind a model instance, from the arguments of your Controller Action. Let's also then assume that we will use a DI framework to inject the SiteConfig object into our Controllers automatically at runtime.
This means that the only problem we have to solve is how to get the injected object from our Controller into its Actions' ViewModels when they are automatically bound.
So let's define a base model for others to inherit from.
BaseViewModel
public class BaseViewModel
{
public ISiteConfig SiteConfig { get; set; }
public BaseViewModel(ISiteConfig siteConfig)
{
this.SiteConfig = siteConfig;
}
}
And now let's create a model that inherits from it.
IndexViewModel
public class IndexViewModel : BaseViewModel
{
public string SomeIndexProperty { get; set; }
public IndexViewModel (ISiteConfig siteConfig) : base(siteConfig) {}
}
And now let's define a Base Controller that our Controllers will inherit from.
BaseController
public abstract class BaseController : Controller
{
protected BaseController(ISiteConfig siteConfig)
{
_siteConfig = siteConfig;
}
private readonly ISiteConfig _siteConfig;
public ISiteConfig SiteConfig
{
get
{
return _siteConfig;
}
}
}
Now we define our actual controller.
HomeController
public HomeController: BaseController
{
public HomeController(ISiteConfig siteConfig): base(siteConfig) {}
}
Assuming we're using Ninject for DI, Ninject would be configured to automatically create the Controller and pass a concrete ISiteConfig object into its Constructor at runtime.
Now we add our Action to the Controller.
Index Action
public ActionResult Index(IndexViewModel model)
{
return View(model);
}
And so this is the point where without doing anything else, MVC will explode with a "Parameterless Constructor" error if you try to call the Index Action, because MVC can't find a ViewModel constructor that takes no arguments.
And so, the answer. We need to override the default ModelBinder.
BaseViewModelBinder
public class BaseViewModelBinder : DefaultModelBinder
{
protected override object CreateModel(ControllerContext controllerContext, ModelBindingContext bindingContext, Type modelType)
{
if (modelType == typeof(BaseViewModel) || modelType.IsSubclassOf(typeof(BaseViewModel)))
{
var baseControl = controllerContext.Controller as BaseController;
if (baseControl == null)
{
throw new Exception("The Controller must derive from BaseController");
}
var instance = Activator.CreateInstance(modelType, baseControl.SiteConfig);
bindingContext.ModelMetadata = ModelMetadataProviders.Current.GetMetadataForType(() => instance, modelType);
return instance;
}
else
{
return base.CreateModel(controllerContext, bindingContext, modelType);
}
}
}
And we need to set this as the default model binder in global.asax.cs :
protected void Application_Start()
{
...
ModelBinders.Binders.DefaultBinder = new BaseViewModelBinder();
}
That's all. As you can see, when you view the Index Action now, MVC will use our custom model binder. It will realise that the IndexViewModel derives from BaseViewModel, and so will attempt to spin up an IndexViewModel instance using the ISiteConfig it can find in the Action's Controller (because the Controller derives from BaseController).
I am creating an application in mvc3 and wondering how to deal with database data which is required for all application requests, some of them depends on a session, some of them depends on url pattern basically all data is in database.
Like to know best practice
What I do in my applications and consider to be the best practice is to load your common data to the ViewBag on the Controller constructor.
For every project, I have a DefaultController abstract class that extends Controller. So, every controller in the project must inherit from DefaultController, instead of Controller. In that class' constructor, I load all data common to the whole project, like so:
// DefaultController.cs
public abstract class DefaultController : Controller
{
protected IRepository Repo { get; private set; }
protected DefaultController(IRepository repo)
{
Repo = repo;
ViewBag.CurrentUser = GetLoggedInUser();
}
protected User GetLoggedInUser()
{
// your logic for retrieving the data here
}
}
// HomeController.cs
public class HomeController : DefaultController
{
public HomeController(IRepository repo) : base(repo)
{
}
// ... your action methods
}
That way you will always have the logged in user available in your views.
I do the same as #rdumont but with one exception: I create a CommonViewModel which I use to define all common properties that I use.
public class CommonViewModel
{
public string UserName {get;set;}
public string Extension {get;set; }
}
Declare a property in the base controller:
public abstract class BaseController : Controller
{
protected CommonViewModel Commons { get; private set; }
protected virtual void OnResultExecuting(ResultExecutingContext filterContext)
{
ViewBag.Commons = Commons;
}
}
By doing so I get everything almost typed. The only cast that I need to do is to cast ViewBag.Commons to the CommonViewModel.
Best is to avoid ViewBag at all.
See this answer, which details how to use Html.RenderAction() for that purpose:
Best way to show account information in layout file in MVC3
I'd suggest using a base ViewModel class.
So a base class with properties/functions which should be available at any point.