How can I access some ViewBag properties across all my views? I want to have some information like current user name, etc accessible everywhere, but without having to to specifically define the properties in each ActionResult method on my project
The best and straight forward way to accomplish your requirement is to make a Custom Base Controller and inherit your Controller from this Base Controller.
public class MyBaseController : Controller
{
protected override void OnActionExecuting(ActionExecutingContext filterContext)
{
ViewBag.someThing = "someThing"; //Add whatever
base.OnActionExecuting(filterContext);
}
}
Now instead of inheriting Controller class,inherit MyBaseController in your Controller as shown :-
public class MyOtherController : MyBaseController
{
public ActionResult MyOtherAction()
{
//Your Stuff
return View();
}
//Other ActionResults
}
You can achieve what you want in a number of ways, each one with their pros and cons.
1. With a Base Class
public class BaseController : Controller
{
protected override ViewResult View(IView view, object model)
{
this.ViewBag.MyProperty = "value";
return base.View(view, model);
}
}
PROS: Quite simple to implement, few lines of code, highly reusable, can be opted-out at will (see comments below).
CONS: Being forced to derive all your controllers from a base class might have some impact, especially if you have a lot of controllers already in place and/or you need to derive them from other base classes.
2. With a Module
public class ViewBagPropertyModule: Module
{
protected override void AttachToComponentRegistration(IComponentRegistry cr,
IComponentRegistration reg)
{
Type limitType = reg.Activator.LimitType;
if (typeof(Controller).IsAssignableFrom(limitType))
{
registration.Activated += (s, e) =>
{
dynamic viewBag = ((Controller)e.Instance).ViewBag;
viewBag.MyProperty= "value";
};
}
}
}
PROS: None I’m aware of.
CONS: None I’m aware of (except being a bit counterintuitive).
3. With a RegisterController Hook
builder.RegisterControllers(asm)
.OnActivated(e => {
dynamic viewBag = ((Controller)e.Instance).ViewBag;
viewBag.MyProperty = "value";
});
PROS: Fast, secure, reusable: ideal for any IoC design pattern.
CONS: Not always suited for small project and/or simple websites: if you’re not using IoC you’re often not using RegisterController at all.
4. With an ActionFilter attribute
public class MyPropertyActionFilter : ActionFilterAttribute
{
public override void OnResultExecuting(ResultExecutingContext filterContext)
{
filterContext.Controller.ViewBag.MyProperty = "value";
}
}
and then in your Global.asax.cs file:
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
GlobalFilters.Filters.Add(new MyPropertyActionFilter(), 0);
}
PROS: Easily the less-obtrusive method amongst those mentioned.
CONS: None I’m aware of.
I also wrote this article on my blog explaining all the above methods.
One way: Create a custom attribute, then you can apply it globally in the FilterConfig. Then you don't have to do anything in your controllers.
public class MyCustomViewActionFilter : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
dynamic ViewBag = filterContext.Controller.ViewBag;
ViewBag.Id = "123";
ViewBag.Name = "Bob";
}
}
In App_Start/FilterConfig.cs:
public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
filters.Add(new MyCustomViewActionFilter());
}
Another way if all you need is the User information. You can add the following to the top of your view:
#using Microsoft.AspNet.Identity
Then access your User Name using the following syntax:
#User.Identity.GetUserName()
You can also override the IPrincipal implementation and provide your own properties and methods to add more information you need to render.
UPDATE: looking at MVC 6 in Asp.Net vNext this is actually baked into the framework. http://www.asp.net/vnext/overview/aspnet-vnext/vc#inj
My current solution:
Create a base controller with all needed properties (very useful and advisable).
public abstract class BaseController : Controller {
public string MyProperty { get; set; }
}
Inherits all your controllers, from the base controller.
public class MyController : BaseController {
//you can read your property here
}
In your views, add this line just after the "#model" sentence:
#{ BaseController ctr = ViewContext.Controller as BaseController; }
Now, you can use the property in your view, without populate the ViewBag, without the need of check and cast the ViewBag values, etc.
In the view, you can use an simple inline expression:
#(ctr.MyProperty)
Or do some magic logic...
#{
if(ctr.MyProperty == "whatelse") {
//do ...
}
}
Easy, fast and comfortable.
For Net Core 5 Mvc app:
Create a ActionFilter class first:
public class GlobalSettingFilter : IActionFilter
{
private IConfiguration configuration;
//For example will get data from the configuration object
public GlobalSettingFilter(IConfiguration configuration)
{
this.configuration = configuration;
}
public void OnActionExecuting(ActionExecutingContext context)
{
//Populate the ViewData or ViewBag from your data source
(context.Controller as Controller).ViewData["helpUrl"] = configuration.GetValue<String>("helpUrl");
}
public void OnActionExecuted(ActionExecutedContext context){}
}
Then, on Startup add:
public void ConfigureServices(IServiceCollection services)
{
...
services.AddControllersWithViews(options =>
{
options.Filters.Add(new GlobalSettingFilter(Configuration));
});
}
Just for the sake of completeness, to get the configuration object use:
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
...
}
You can create a base controller that is inherited by all of your controllers, and in this controller (the base one) add:
protected override void OnActionExecuting(ActionExecutingContext filterContext)
{
// Fill your global viewbag variables here
}
I need to do the following:
I have some Controllers ready and running, but now I want to create a BaseController.
Each of my Controllers should inherit from it like this:
public class MySecondController : BaseController
thats already running so far. Now the Problem:
I want to add a ViewBag into this base controller. This ViewBag should be accessable from every view which is called in my controllers.
How to realise this?
You can override OnActionExecuting method in the overridden method you can data to ViewBag dictionary.
public abstract class BaseController : Controller
{
protected override void OnActionExecuting(ActionExecutingContext filterContext)
{
ViewBag.someThing = "someThing"; //Add whatever
base.OnActionExecuting(filterContext);
}
}
Updated for .net Core 2019:
using Microsoft.AspNetCore.Mvc.Filters;
public abstract class BaseController : Controller
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
ViewBag.someThing = "someThing"; //Add whatever
ViewData["someThingElse"] = "this works too";
TempData["anotherThing"] = "as does this";
base.OnActionExecuting(filterContext);
}
}
I've got an abstract class shown below which gets inherited by all the other controllers. Is it possible to test this method at all? Btw, I'm trying to use MOQ but no luck. If you could help me will be much appreciated:
public abstract class ApplicationController : Controller
{
protected override void Initialize(System.Web.Routing.RequestContext requestContext)
{
base.Initialize(requestContext);
//do some stuff here
}
}
If you take a look at the source code of base Initialize method you will find out that what it does is that it sets up ControllerContext and url stuff. Now, download MvcContrib TestHelper and check out TestControllerBuilder . The builder sets up everything you need in order to have controller context and other stuff which you depend upon.
Ok, we are not over yet - you wanted to test your own override of Initialize right?
TestControllerBuilder doesnt call your Initialize because it does initialization in different way. I suggest you to factor out your custom Initialize() logic out into different method. Then create fake (stub) subclass with public method that calls this factored out protected Initialize. Are you with me?
something like:
public abstract class ApplicationController : Controller
{
protected override void Initialize(System.Web.Routing.RequestContext requestContext)
{
base.Initialize(requestContext);
MyInitialzie()
}
protected void MyInitialize()
{
ControllerContext.XXX // do whatewer you want here. Context is already setted up
}
}
class FakeController: ApplicationController
{
public void CallMyInitialize()
{
MyInitialize();
}
}
Later in test class:
[Test]
public void MyInitializeTest()
{
TestControllerBuilder builder = new TestControllerBuilder();
FakeController controller = new FakeController();
builder.InitializeController(controller);
controller.CallMyInitialize();
//TODO: verification of MyInitialize assumptions
}
Is that clear?
All my controllers inherit from a BaseController that has an ActionFilter attribute:
[AnalyticsData]
public class BaseController : Controller {}
public class AccountController : BaseController {}
Some of my Actions in my controllers reuse the AnalyticsData ActionFilter:
public class AccountController : BaseController
{
[AnalyticsData(Page="AccountProfile")]
public ActionResult Profile()
{
// return View
}
}
I notice that the AnalyticsData ActionFilter only runs once. This is a good thing and I only want it to run once, but I'm wondering how that happens. If I set my breakpoint inside the OnActionExecuting:
public class AnalyticsAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
// break point set here
}
}
...it only gets hit once when AccountController serves it Profile view.
How do ActionFilters and/or Attributes work that [AnalyticsData(Page="AccountProfile")] on the Action overrides/replaces [AnalyticsData] on BaseController?
The short answer is that the ASP.NET MVC framework code that retrievs the list of filters for each action removes duplicates (action filters of the same type) in such a way that it prefers actionfilters defined on the action method over ones defined on the controller (or its base class). In MVC 2 this logic is performed in a few internal methods in the ActionDescriptor class
I need to have some navigation options, that require keys that are specific to the current user, that reside in a masterpage. I need some advice on best practise.
In have the following links in a left nav in a masterpage
http://www.example.com/manageShop/123
http://www.example.com/addProductToShop/123
http://www.example.com/addStaffToShop/123
Where '123' is the shop id that the current user is the manager of. I need some way of passing this to the masterpage
Currently I'm going something to this effect:
<li><%= Html.ActionLink<ShopController>(x => x.ManageShop((int)Session["ShopKey"]), "Manage")%></li>
I thought this was a good idea as I only have to set the ShopKey once in the session and its done, the down side is that iv noticed that the session gets mixed if you have the site open is two tabs.
Alternatively I tried this:
<li><%= Html.ActionLink<ShopController>(x => x.ManageShop((int)ViewData["ShopKey"]), "Manage")%></li>
But this means you have to keep setting the ViewData in every action in every controller. Which is awful.
EDIT: I have had alook at filters like eu-ge-ne suggested below, but I dont this really solves my problem as I still have the issue of setting the ShopKey everywhere?
What is the solution?
You can create custom filter for this:
public class UserKeyAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
filterContext.Controller.ViewData["UserKey"] = UserKey;
}
}
and use it on your controller or controller actions
[UserKey]
public class YourController : Controller
{
// or
public class YourController : Controller
{
[UserKey]
public ActionResult Index()
{
or use Controller.OnActionExecuting() (or even create base controller for this as Arnis L. said):
public class BaseController : Controller
{
protected override void OnActionExecuting(ActionExecutingContext filterContext)
{
filterContext.Controller.ViewData["UserKey"] = UserKey;
}
}
// and then derive your controllers from BaseController
public class YourController : BaseController
{