Here's my scenario:
I've successfully created a custom IIdentity that I pass to a GenericPrincipal. When I access that IIdentity in my controller I have to cast the IIdentity in order to use the custom properties. example:
public ActionResult Test()
{
MyCustomIdentity identity = (MyCustomIdentity)User.Identity;
int userID = identity.UserID;
...etc...
}
Since I need to do this casting for nearly every action I would like to wrap this functionality in an ActionFilterAttribute. I can't do it in the controller's constructor because the context isn't initialized yet. My thought would be to have the ActionFilterAttribute populate a private property on the controller that I can use in each action method. example:
public class TestController : Controller
{
private MyCustomIdentity identity;
[CastCustomIdentity]
public ActionResult()
{
int userID = identity.UserID;
...etc...
}
}
Question: Is this possible and how? Is there a better solution? I've racked my brain trying to figure out how to pass public properties that are populated in an attribute to the controller and I can't get it.
All you have to do is access the ActionExecutingContext of an overloaded OnActionExecuting() method and make identity public instead of private so your actionfilter can access it.
public class CastCustomIdentity : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
((TestController) filterContext.Controller).Identity = (MyCustomIdentity)filterContext.HttpContext.User;
base.OnActionExecuting(filterContext);
}
}
This could be even easier by using a custom base controller class that all of your controllers would inherit from:
public class MyCustomController
{
protected MyCustomIdentity Identity { get{ return (MyCustomIdentity)User.Identity; } }
}
and then:
public class TestController : MyCustomController
{
public ActionResult()
{
int userID = Identity.UserId
...etc...
}
}
You could use a custom model binder...
I can't remember why I used this method over the base controller method #jfar mentions (which is also a good option), but it works well for me and I actually kinda like it because my actions are more self describing through their parameters.
MyCustomIdentityModelBinder.cs
public class MyCustomIdentityModelBinder : IModelBinder
{
public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
if (bindingContext.Model != null)
throw new InvalidOperationException("Cannot update instances");
//If the user isn't logged in, return null
if (!controllerContext.HttpContext.User.Identity.IsAuthenticated)
return null;
return controllerContext.HttpContext.User as MyCustomIdentity;
}
}
Inside your application start event in Global.asax.cs
System.Web.Mvc.ModelBinders.Binders.Add(typeof(MyCustomIdentity), new MyCustomIdentityModelBinder());
Then whenever you have a type of MyCustomIdentity as an action parameter, it'll automatically use the MyCustomIdentityModelBinder.
Eg.
public class TestController : Controller
{
public ActionResult Index(MyCustomIdentity identity)
{
int userID = identity.UserID;
...etc...
}
}
HTHs,
Charles
Related
I am trying to make sure that my MVC application only uses one DbContext per Request in order to reduce number of times a Db connection is open and so there are no concurrency issues.
This means i will need to use the same context in my Global Action Filters as well as my Controllers.
I have tried something like this
public class LayoutFilter : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
MembershipUser loggedInUser = Membership.GetUser();
MyUnitOfWork uow = new MyUnitOfWork();
ViewBag.FullName = uow.UserService.GetUser().FullName
filterContext.ActionParameters["unitOfWork"] = uow;
}
}
However the context is disposed when i try to read it from the controller as shown below
public ActionResult Logout(MyUnitOfWork uow)
{
ViewBag.Something = uow.ExampleService.GetMyObject();
return RedirectToAction("LogIn");
}
I get the same issue with the context being disposed when i try to share the same unitOfWork object by casting a property of a base controller class
public class BaseController : Controller
{
public RequestboxUnitOfWork unitOfWork;
}
public class LayoutFilter : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
MembershipUser loggedInUser = Membership.GetUser();
BaseController baseController = (BaseController)filterContext.Controller;
ViewBag.FullName = baseController.unitOfWork.UserService.GetUser().FullName
filterContext.ActionParameters["unitOfWork"] = uow;
}
}
The context is disposed when i try to access it in the controller and i have read in a few places that you should not use base controller class so i am unsure of what i can do.
What are the recommended ways to share a entity context between ActionFilters and Controllers
Create the DBContext as part of the Controller setup, and have it available via an internal property on the controller.
public class MyController : Controller
{
private MyUnitOfWork unitOfWork;
internal MyUnitOfWork UnitOfWork
{
get { return unitOfWork; }
}
}
You will then be able to access the context in the filter attribute like this:
MyController controller = (MyController)filterContext.Controller
MyUnitOfWork uow = controller.UnitOfWork;
There's no need to pass the unit of work back to the action method in the controller, because the controller already has the object, and it can be accessed via the same internal property.
I am new to mvc and I load ViewBag in a method of controller as,
HomeController: Controller
{
Public ActionResult Index()
{
loadViewBag();
return View();
}
public void loadViewBag()
{
ViewBag.aaa = "something";
}
}
It works fine.
What is my problem is, Now I want to call loadViewBag() method form another controller( say Account) so that I can reuse same method and need to make loadViewBag() method static due to some static variables as:
public static void loadViewBag()
If I make loadViewBag method static, there appear error on ViewBag " An object reference is required for the non-static field, method, or property 'System.Web.Mvc.ControllerBase.ViewBag.get' ".
Is there any solution/suggestion.
Thank You.
Just make it an extension method of ControllerBase e.g.
public static void ControllerExt
{
public static void LoadViewBag(this ControllerBase controller)
{
controller.ViewBag.aaa = "something";
...
}
}
That way you can use it in any controller
public class HomeController : Controller
{
public ActionResult Index()
{
this.LoadViewBag();
return View();
}
}
public class AccountController : Controller
{
public ActionResult Index()
{
this.LoadViewBag();
return View();
}
}
If its only specific to some controllers then it would be more flexible to pass the ViewBag property in e.g.
public static class ControllerHelper
{
public static void LoadViewBag(dynamic viewBag)
{
viewBag.aaa = "something";
}
}
public class HomeController : Controller
{
public ActionResult Index()
{
ControllerHelper.LoadViewBag(ViewBag);
return View();
}
}
ViewBag is a property of your controller (more specifically of ControllerBase), and since a static method has no knowledge of a class instance, you can't access it.
You could pass the controller instance to the method if you want to use a static method or even make it an extension method, but depending on your problem, this solution could be sub-optimal. You may be able to get a better answer if you add more details to your question.
Public ActionResult Index()
{
this.loadViewBag();
return View();
}
public static void loadViewBag(this ControllerBase target)
{
target.ViewBag.aaa = "something";
}
Do you need that to allow different controllers/views to use some common properties?
Then I'd rather recommend a common base controller, while also wrapping ViewBag code into type safe properties (to let the compiler control the data consistency - as you know, ViewBag is not type safe, so any typos and data mismatches won't be noticed until the code gets executed).
1. Introduce a common controller with those wrapper properties
public abstract class MyBaseController : Controller
{
internal long CurrentUserId
{
get { return ViewBag.CurrentUserId; }
set { ViewBag.CurrentUserId = value; }
}
internal Role CurrentUserRole
{
get { return ViewBag.CurrentUserRole; }
set { ViewBag.CurrentUserRole = value; }
}
...
}
Thus, your inherited controllers could simply set the properties - or, with lots of common code just introduce a method in your base controller - similar to what you already have.
2. Introduce a common view class with those wrapper properties
public abstract class MyBaseViewPage<T> : WebViewPage<T>
{
public string Title
{
get { return (string)ViewBag.Title; }
set { ViewBag.Title = value; }
}
public long CurrentUserId
{
get { return (long)ViewBag.CurrentUserId; }
}
public Role CurrentUserRole
{
get { return ViewBag.CurrentUserRole; }
}
}
public abstract class MyBaseViewPage : MyBaseViewPage<dynamic>
{
}
and update web.config to let MVC know you're using a custom base view:
<configuration>
...
<system.web.webPages.razor>
...
<pages pageBaseType="MyRootNamespace.Views.MyBaseViewPage">
...
</pages>
</system.web.webPages.razor>
Now you can use them as normal properties in your controllers and views.
We use a BaseController to cache basic authentication information before every action executes:
public abstract class BaseController : Controller
{
protected bool IsLoggedIn { get; set; }
protected string Username { get; set; }
...
protected override void OnActionExecuting(ActionExecutingContext filterContext)
{
var identity = base.User.Identity;
this.IsLoggedIn = identity.IsAuthenticated;
this.Username = identity.Name;
...
}
}
And our child controller has a actions for the main page (Index) and a partial view (GetNavigation):
[Authorize]
public partial class CollaborationController : BaseController
{
[HttpGet]
public virtual ViewResult Index()
{
var viewModel = this.MakeViewModel<FullPageViewModel>();
return this.View(MVC.Collaboration.Views.Index, viewModel);
}
[HttpGet]
public virtual PartialViewResult GetNavigation()
{
var viewModel = NavigationViewModel.Make(this.User);
return this.PartialView(MVC.Collaboration.Views.Navigation, viewModel);
}
}
And the partial view is rendered directly with Html.Action():
#Html.Action(MVC.Collaboration.GetNavigation())
Seems like it should work, but BaseController.OnActionExecuting does not get called. And I can't even call it directly because this.ControllerContext and base.User are both null. I also tried subclassing ActionFilterAttribute, but its OnActionExecuting method doesn't get called, either.
I know this is an old question but here is how I handle this. In my child controller I create the OnActionExecuting method and call the base controller from there.
protected override void OnActionExecuting(ActionExecutingContext filterContext)
{
base.OnActionExecuting(filterContext);
}
At least sort-of answered my own question:
Substituting
#Html.Action("GetNavigation", "Collaboration")
for
#Html.Action(MVC.Collaboration.GetNavigation())
fixes it. MVCContrib's syntax seems to be the culprit, anyone know why? Even better, anyone know a work-around that lets me avoid those nasty, non-refactoring-safe, magic strings?
I want to create an action filter that will be used by ONLY two controllers in my app... This action filter is supposed to be checked for every action inside the TWO controllers.
Heres my action filter code
public class AllowedToEditEHRFilter : IActionFilter
{
IUnitOfWork unitOfWork;
IRepository<EHR> ehrRepository;
public AllowedToEditEHRFilter(IUnitOfWork dependency)
{
unitOfWork = dependency;
ehrRepository = unitOfWork.EHRs;
}
public void OnActionExecuting(ActionExecutingContext filterContext)
{
int ehrId;
if (int.TryParse(filterContext.HttpContext.Request.QueryString["ehrId"], out ehrId))
{
EHR ehr = ehrRepository.FindById(ehrId);
if (ehr.UserName != Membership.GetUser().UserName)
filterContext.Result = new ViewResult { ViewName = "InvalidOwner" };
}
}
public void OnActionExecuted(ActionExecutedContext filterContext)
{
}
}
Now Im just not sure how can I configure MVC framework so that the action filter gets triggered at the appropriate times.
Im using this as reference but that is applying a GLOBAL actionfilter and it doesnt specify how to limit to just some of your controllers.
Please help.
btw Im using NinjectMVC3
This depends on what the appropriate time is.
See my original blog post
http://www.planetgeek.ch/2010/11/13/official-ninject-mvc-extension-gets-support-for-mvc3/
Or read the other pages of the doc:
https://github.com/ninject/ninject.web.mvc/wiki/Conditional-bindings-for-filters
https://github.com/ninject/ninject.web.mvc/wiki/Filter-configurations
(Probably I should link them)
Basically you need to configure a binding for the filter and define some condition:
kernel.BindFilter<AllowedToEditEHRFilter>(FilterScope.Action, 0).When...
e.g.
.WhenActionHas<AllowedToEditEHRAttribute>()
Update:
In your case simply
kernel.BindFilter<AllowedToEditEHRFilter>(FilterScope.Controller, 0).When(
(controllerContext, actionDescriptor) =>
controllerContext.Controller is PhysicalTestsController)
To apply the action filter to only some of your controllers, simply add the attribute to the controllers in question.
[AllowedToEditEHR]
public class YourController : Controller
{
...
For this to work, you should rename your filter to AllowedToEditEHRAttribute, i.e. replace "Filter" by "Attribute". This is a standard naming convention for attributes.
Update: To inject dependencies in the filter, just decorate it's constructor with the [Inject] attribute.
public class AllowedToEditEHRFilter : IActionFilter
{
IUnitOfWork unitOfWork;
IRepository<EHR> ehrRepository;
public AllowedToEditEHRFilter(IUnitOfWork dependency)
{
unitOfWork = dependency;
ehrRepository = unitOfWork.EHRs;
}
public void OnActionExecuting(ActionExecutingContext filterContext)
{
int ehrId;
if (int.TryParse(filterContext.ActionParameters["ehrId"].ToString(), out ehrId))
{
EHR ehr = ehrRepository.FindById(ehrId);
if (ehr.UserName != Membership.GetUser().UserName)
filterContext.Result = new ViewResult { ViewName = "InvalidOwner" };
}
}
public void OnActionExecuted(ActionExecutedContext filterContext)
{
}
}
And the CustomFilterProvider
public class ConfiguredFilterProvider : IFilterProvider
{
private readonly IKernel _kernel;
public ConfiguredFilterProvider(IKernel kernel)
{
_kernel = kernel;
}
public IEnumerable<Filter> GetFilters(ControllerContext controllerContext, ActionDescriptor actionDescriptor)
{
List<Filter> list = new List<Filter>();
if (controllerContext.Controller is PhysicalTestsController)
{
list.Add(new Filter(
_kernel.Get(typeof(AllowedToEditEHRFilter)),
FilterScope.Global, order: null
));
}
return list;
}
}
And in Ninject
kernel.Bind<IFilterProvider>()
.To<ConfiguredFilterProvider>();
It might not be the cleanest solution but its working.
You just have to decorate that two controllers with the action filter like this
[AllowedToEditEHRFilter]
public class YourController : Controller
{
...
}
However, I am not sure if it is allowed to have a complex object passed in a constructor of that filter.
Instead of implementing IActionFilter, extend ActionFilterAttribute and then assign the attribute to the two controllers you want to affect:
public class AllowedToEditEHRFilter : ActionFilterAttribute
{
// ...
}
and:
[AllowedToEditEHRFilter]
public class MyController : Controller
{
// ...
}
In asp.net MVC, dependency injection with controllers is simple and straightforward. Now, I'd like to remove most of the logic from views by using helpers. The problem is that these helpers use some of the objects that are injected.
Let me write an example:
public interface ISessionData
{
List<string> IdList {get;}
}
public MyController : Controller
{
public MyController(ISessionData sessionData)
{
...
}
}
session data is injected into controller. So far so good. But now I have a helper. Let's say it looks like this:
public class MyHelper
{
private readonly ISessionData sessionData;
public MyHelper(ISessionData sessionData)
{
this.sessionData = sessionData;
}
public bool CheckSomethingExistsInSession(string id)
{
return sessionData.IdList.Any(x => x.Id.Equals(id));
}
}
Now what? I'd like MyHelper to be injected into view. Only way I can see is adding this helper to model and passing it to view every time. Any other ideas?
In MVC it is better to pass ISessionData data from Controller to View (using ViewModel or ViewData):
ViewData["Session"] = sessionData.IdList.ToList();
And remove ISessionData dependency from the helper. Something like this:
public class MyHelper
{
//private readonly ISessionData sessionData;
public MyHelper(/*ISessionData sessionData*/)
{
//this.sessionData = sessionData;
}
public bool CheckSomethingExistsInSession(string id, IList<...> sessionData)
{
return sessionData.Any(x => x.Id.Equals(id));
}
}
In View:
<% var somethingExists = new MyHelper().CheckSomethingExistsInSession(
1, ViewData["Session"] as IList<...>); %>
UPDATED:
public static class MyHelper
{
public static bool CheckSomethingExistsInSession(string id, IList<...> sessionData)
{
return sessionData.Any(x => x.Id.Equals(id));
}
}
<% var somethingExists = MyHelper.CheckSomethingExistsInSession(
1, ViewData["Session"] as IList<...>); %>
You should remove session logic from your controller's constructor and insert it into the controllers action method by using an IModelBinder. See below:
public class SessionDataModelBinder : IModelBinder
{
public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
// Get/create session data implementating ISeesionData or whatever here. This will be return to the controller action method.
return new SessionData()
}
}
On you controller you would do something like:
public MyController : Controller
{
public MyController()
{
....
}
public ActionResult Index(ISessionData sessionData)
{
// do stuff with ISessionData.
// Redirect or whatever.
return this.RedirectToAction("Index");
}
}
You need to add your IModelBinder like below for it to be called. You can do this in the http application's startup.
System.Web.Mvc.ModelBinders.Binders[typeof(ISessionData)] = new SessionDataModelBinder();