Chose to render different View (ASPX) file in ASP.NET MVC - asp.net-mvc

I have this
public class HomeController{
public ActionResult Index()
{
//do stuff
return View();
}
Obviously this choses and renders Index.aspx in the Home folder.
What we really want is to chose another file - Index.ar.aspx - if the CurrentCulture is ar-AE. I don't want IF statements on every return View() call. Anyone help me find the best place to override the name of the view file that is selected?
Note, please don't tell me off :) I know that separate files are a bit hacky, and we ARE using RESX files, DIR directives and routes to change languages etc. But we need seperate files for layout reasons.

You should create your own ViewEngine. If you are using the WebFormViewEngine that is the default one with MVC, you could easily subclass it and then override the FindView(...) method.
In your overridden FindView(...) method you could easily look for a file based on a convention that includes the name of the current culture.
Take a look at Scott Hanselmans post about a ViewEngine that looks for different view files if the site is browsed using a mobile device.
Perhaps something like:
public class ExampleViewEngine : WebFormViewEngine
{
public override ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName, bool useCache)
{
ViewEngineResult result = null;
string conventionViewName = string.Format("{0}.{1}", viewName, System.Globalization.CultureInfo.CurrentCulture.TwoLetterISOLanguageName);
result = base.FindView(controllerContext, conventionViewName, masterName, useCache);
if (result == null || result.View == null)
{
result = base.FindView(controllerContext, viewName, masterName, useCache);
}
return result;
}
}

It sounds like you really want the View engine to be able to decide which view to return, rather than having the controllers be responsible for it.
Take a look at this tutorial, and google around for some others. It's pretty simple to override the default view engine, and you can add the language choosing logic there, removing the need for it at the controller level.

public class BaseController{
// Don't remember parameter type exactly
public void OnActionExecuted(ActionExecutedContext context)
{
// if view is returned, add culture suffix to its name
// also may need to do so for PartialViewResult
// One problem is if view is not named; Name is "";
// in this case use context.ActionContext.Name or RouteData["action"] for view name
if (context.Result is ViewResult)
{
var view = context.Result as ViewResult;
view.Name = view.Name + CurrentCultureSuffix;
}
}
}
public class HomeController: BaseController{
public ActionResult Index()
{
//do stuff
return View();
}
}

Related

A clean solution to use multiple submit button in ASP.NET MVC

I found some similar questions and I like the solution with the "MultipleButtonAttribute" found at here: How do you handle multiple submit buttons in ASP.NET MVC Framework?
But I come up with another solution and I thought I share it with the community.
So first of all I make a ModelBinder that handle the incoming request.
I have to made a restriction. input/button element id and name must be a prefix of "cmd".
public class CommandModelBinder<T> : IModelBinder
{
public CommandModelBinder()
{
if (!typeof(T).IsEnum)
{
throw new ArgumentException("T must be an enumerated type");
}
}
public object BindModel(System.Web.Mvc.ControllerContext controllerContext, ModelBindingContext bindingContext)
{
string commandText = controllerContext.HttpContext.Request.Form.AllKeys.Single(key => key.StartsWith("cmd"));
return Enum.Parse(typeof (T), commandText.Substring(3));
}
}
Of course it can be changed or make it to configurable via web.config of App_Start.
The next thing I make is a HtmlHelper extension to generate the necessary HTML markup:
public static MvcHtmlString CommandButton<T>(this HtmlHelper helper, string text, T command)
{
if (!command.GetType().IsEnum) throw new ArgumentException("T must be an enumerated type");
string identifier = "cmd" + command;
TagBuilder tagBuilder = new TagBuilder("input");
tagBuilder.Attributes["id"] = identifier;
tagBuilder.Attributes["name"] = identifier;
tagBuilder.Attributes["value"] = text;
tagBuilder.Attributes["type"] = "submit";
return new MvcHtmlString(tagBuilder.ToString());
}
It's still a tech demo so the html attribute and the other super overloads waiting for you to develop on your own.
Now we have to make some enumerations to try our code. They can be general or controller specific:
public enum IndexCommands
{
Save,
Cancel
}
public enum YesNo
{
Yes,
No
}
Now pair the enumerations with the binders. I do it in different file in the App_Start folder. ModelBinderConfig.
ModelBinders.Binders.Add(typeof(IndexCommands), new CommandModelBinder<IndexCommands>());
ModelBinders.Binders.Add(typeof(YesNo), new CommandModelBinder<YesNo>());
Now after we set up everything, make an action to try the codes. I kept it simple so:
public ActionResult Index()
{
return View();
}
[HttpPost]
public ActionResult Index(IndexCommands command)
{
return View();
}
And my view looks like this:
#using (Html.BeginForm())
{
#Html.CommandButton("Save", IndexCommands.Save)
#Html.CommandButton("Cancel", IndexCommands.Cancel)
}
Hope this helps to keep your code clear, type safe and readable.

Changing the view in an ASP.NET MVC Filter

I want to redirect the user to a different view if they are using a mobile browser. I've decided I'd like to do this using MVC filters by applying it to actions which I want to have a mobile view.
I believe this redirect needs to happen in OnActionExecuted, however the filterContext does not contain information on the view - it does, however in OnResultExecuted, but by this time I believe it is too late to change the view.
How can I intercept the view name and change the ViewResult?
This is what I have in the result executed and what I'd like to have work in Action Executed.
public class MobilePageFilter : ActionFilterAttribute
{
public override void OnResultExecuted(ResultExecutedContext filterContext)
{
if(filterContext.Result is ViewResult)
{
if (isMobileSite(filterContext.HttpContext.Session[SetMobile.SESSION_USE_MOBILE]))
{
ViewResult viewResult = (ViewResult)filterContext.Result;
string viewName = viewResult.ViewName;
filterContext.Result = new ViewResult
{
ViewName = "Mobile/" + viewName,
ViewData = viewResult.ViewData,
TempData = viewResult.TempData
};
}
}
base.OnResultExecuted(filterContext);
}
}
I would recommend you the following blog post which explains a better alternative to achieve what you are asking for rather than using action filters.
This is what I ended up doing, and wrapped up into a reusable attribute and the great thing is it retains the original URL while redirecting (or applying whatever result you wish) based on your requirements:
public class AuthoriseSiteAccessAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
base.OnActionExecuting(filterContext);
// Perform your condition, or straight result assignment here.
// For me I had to test the existance of a cookie.
if (yourConditionHere)
filterContext.Result = new SiteAccessDeniedResult();
}
}
public class SiteAccessDeniedResult : ViewResult
{
public SiteAccessDeniedResult()
{
ViewName = "~/Views/SiteAccess/Login.cshtml";
}
}
Then just add the attribute [SiteAccessAuthorise] to your controllers you wish to apply the authorisation access to (in my case) or add it to a BaseController. Make sure though the action you are redirecting to's underlying controller does not have the attribute though, or you'll be caught in an endless loop!

Cannot resolve view of the parent controller

Create a controller:
public abstract class MyBaseController : Controller
{
public ActionResult MyAction(string id)
{
return View();
}
}
Than create another specific controller that inherit from MyBaseController:
public class MyController : MyBaseController
{
}
There is a view called MyAction.aspx in the Views/MyBaseController folder
Then, call MyController/MyAction method. Following exception will be generated:
The view 'MyAction' or its master
could not be found. The following
locations were searched:
~/Views/MyController/MyAction.aspx
~/Views/MyController/MyAction.ascx
~/Views/Shared/MyAction.aspx
~/Views/Shared/MyAction.ascx
Can I make MVC.NET to use the view from Views/MyBaseController folder?
you should wait for a more finesse answer but this work:
Create a new view engine based on the default one and override the FindViewMethod this way:
public class MyNewViewEngine : WebFormViewEngine
{
public override ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName, bool useCache)
{
var type = controllerContext.Controller.GetType();
//Retrieve all the applicable views.
var applicableViews = from m in type.GetMethods()
where typeof(ActionResult).IsAssignableFrom(m.ReturnType) & m.Name == viewName
select m;
//Save the original location formats.
var cacheLocations = ViewLocationFormats;
var tempLocations = cacheLocations.ToList();
//Iterate over applicable views and check if they have been declared in the given controller.
foreach(var view in applicableViews)
{
//If not, add a new format location to the ones at the default engine.
if (view.DeclaringType != type)
{
var newLocation = "~/Views/" + view.DeclaringType.Name.Substring(0, view.DeclaringType.Name.LastIndexOf("Controller")) + "/{0}.aspx";
if (!tempLocations.Contains(newLocation))
tempLocations.Add(newLocation);
}
}
//Change the location formats.
ViewLocationFormats = tempLocations.ToArray();
//Redirected to the default implementation
var result = base.FindView(controllerContext, viewName, masterName, useCache);
//Restore the location formats
ViewLocationFormats = cacheLocations;
return result;
}
}
Add the new view engine:
public class MvcApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
ViewEngines.Engines.Clear();
ViewEngines.Engines.Add(new MyNewViewEngine());
RegisterRoutes(RouteTable.Routes);
}
}
hope this helps
You need to add it to shared because you are in the context of the subcontroller. If you want different behavior for different controllers, then you'll want to put a MyAction view in each of your subcontroller view folders.
To answer your question though, you probably could make it look in base controller folder, but it would require you to write your own request handler which looks in base controller folders. The default implementation only looks in the view folder for the current controller context, then it looks in the shared folder. It sounds like your view is shared however, so the shared folder seems like a good place for it anyway.
It is possible, but not very clean.
public class MyController : MyBaseController
{
public ActionResult MyAction(string id)
{
return View("~/Views/MyBaseController/MyAction.aspx");
}
}
However if your View (MyAction.aspx) contains a reference to a Partial View, ASP.NET MVC will look for it in the Views/MyController folder (and not find it there!).
If your view is shared across controllers, its best to place it in the Views/Shared folder as recommended by NickLarsen.

Bestpractice DI with ASP.NET MVC and StructureMap - How to inject dependencies in an ActionResult

I edited my whole question, so do not wonder :)
Well, I want to have an ActionResult that takes domain model data and some additional parameters, i.e page index and page size for paging a list. It decide itself if it returns a PartialViewResult or a ViewResult depending on the kind of web request (ajax request or not).
The reffered data shall be mapped automatically by using an IMappingService, which is responsible for transforming any domain model data into a view model.
The MappingService uses AutoMapper for simplicity.
MappingActionResult:
public abstract class MappingActionResult : ActionResult
{
public static IMappingService MappingService;
}
BaseHybridViewResult:
public abstract class BaseHybridViewResult : MappingActionResult
{
public const string defaultViewName = "Grid";
public string ViewNameForAjaxRequest { get; set; }
public object ViewModel { get; set; }
public override void ExecuteResult(ControllerContext context)
{
if (context == null) throw new ArgumentNullException("context");
var usePartial = ShouldUsePartial(context);
ActionResult res = GetInnerViewResult(usePartial);
res.ExecuteResult(context);
}
private ActionResult GetInnerViewResult(bool usePartial)
{
ViewDataDictionary viewDataDictionary = new ViewDataDictionary(ViewModel);
if (String.IsNullOrEmpty(ViewNameForAjaxRequest))
{
ViewNameForAjaxRequest = defaultViewName;
}
if (usePartial)
{
return new PartialViewResult { ViewData = viewDataDictionary, ViewName = ViewNameForAjaxRequest };
}
return new ViewResult { ViewData = viewDataDictionary };
}
private static bool ShouldUsePartial(ControllerContext context)
{
return context.HttpContext.Request.IsAjaxRequest();
}
}
AutoMappedHybridViewResult:
public class AutoMappedHybridViewResult<TSourceElement, TDestinationElement> : BaseHybridViewResult
{
public AutoMappedHybridViewResult(PagedList<TSourceElement> pagedList)
{
ViewModel = MappingService.MapToViewModelPagedList<TSourceElement, TDestinationElement>(pagedList);
}
public AutoMappedHybridViewResult(PagedList<TSourceElement> pagedList, string viewNameForAjaxRequest)
{
ViewNameForAjaxRequest = viewNameForAjaxRequest;
ViewModel = MappingService.MapToViewModelPagedList<TSourceElement, TDestinationElement>(pagedList);
}
public AutoMappedHybridViewResult(TSourceElement model)
{
ViewModel = MappingService.Map<TSourceElement, TDestinationElement>(model);
}
public AutoMappedHybridViewResult(TSourceElement model, string viewNameForAjaxRequest)
{
ViewNameForAjaxRequest = viewNameForAjaxRequest;
ViewModel = MappingService.Map<TSourceElement, TDestinationElement>(model);
}
}
Usage in controller:
public ActionResult Index(int page = 1)
{
return new AutoMappedHybridViewResult<TeamEmployee, TeamEmployeeForm>(_teamEmployeeRepository.GetPagedEmployees(page, PageSize));
}
So as you can see the IMappingService is hidden. The controller should not know anything about the IMappingService interface, when AutoMappedHybridViewResult is used.
Is the MappingActionResult with the static IMappingServer appropriate or am I violating the DI principle?
I think a better design is to have a ViewResultFactory that depends on IMappingService, then you can inject that into your controller. Then you call it like so:
public class MyController : Controller
{
IViewResultFactory _viewResultFactory;
ITeamEmployeeRepository _teamEmployeeRepository;
public MyController(IViewResultFactory viewResultFactory)
{
_viewResultFactory = viewResultFactory;
}
public ActionResult MyAction(int page, int pageSize)
{
return
_viewResultFactory.GetResult<TeamEmployee, TeamEmployeeForm>(
_teamEmployeeRepository.GetPagedEmployees(page, pageSize));
}
}
The implementation would like this (you would need to create overloads for each of your HybridViewResult constructors):
public HybridViewResult<TSourceElement, TDestinationElement> GetResult<TSourceElement, TDestinationElement>(PagedList<TSourceElement> pagedList)
{
return new HybridViewResult<TSourceElement, TDestinationElement>(_mappingService, pagedList);
}
That way you hide the implementation from your controllers, and you don't have to depend on the container.
There are a few different points that you could inject IMappingService. http://codeclimber.net.nz/archive/2009/04/08/13-asp.net-mvc-extensibility-points-you-have-to-know.aspx is a good site for help in picking the appropriate extensibility points for .NET MVC.
If you want to stick with having this functionality be a derived ActionResult, then I think you could put the dependency in the ActionInvoker if you want to, but the Controller makes more sense to me. If you don't want the IMappingService in the Controller, you could always wrap it in a HybridViewResultFactory, and access that object in the Controller. In that case your shortcut methods would look like:
public HybridViewResult<TSourceElement, TDestinationElement> AutoMappedHybridView<TSourceElement,TDestinationElement>(PagedList<TSourceElement> pagedList, string viewNameForAjaxRequest)
{
HybridViewResultFactory.Create<TSourceElement, TDestinationElement>(pagedList, viewNameForAjaxRequest);
}
etc.
I'm not sure why you need to use an ActionResult, but if there is no reason that makes it explicitly necessary, you could create a HybridViewModel class and a HybridViewModelBinder class that is injected with the mapping service dependency.
I am assuming you want to use constructor injection, but if you have the StructureMap dependency in your UI assembly, you could access a static dependency resolver class (like Clowers said).
This question would be easier to give a definite answer to if I understood why you using an ActionResult.
It seems like you are using the action result to handle two functionalities that do not necessarily go together all the time, and that could be used separately. Also, there is not a clear indication that it needs to be in an ActionResult.
Presumably, you could (a) leverage the Automapper functionality for results other than html (ViewResult) output, and (b) you could leverage the functionality of auto-detecting ajax requests without needing to automap the model.
It seems to me like the automapping of the view model could be used to inject the view model into the controller action directly, thus removing the controller's dependency on the IMappingService. What you would need is a ModelBinder class to be injected with your IMappingService (the implementation of which I assume contains a repository or datastore type dependency).
Here is a good article explaining how to leverage model binders: http://odetocode.com/blogs/scott/archive/2009/04/27/6-tips-for-asp-net-mvc-model-binding.aspx.
Then you can overwrite the DefaultModelBinder in the classes that need to be Automapped as follows:
public ActionResult DoItLikeThis([AutoMap(typeof(MyDomainModelClass))]MyViewModelClass viewModel){
//controller action logic
}
Now, regarding the HybridViewResult, I would suggest that you handle this with an Action Filter instead. So, you could just use ActionResult or ViewResultBase as the Result type of your action method and decorate it with an action filter, i.e.:
[AutoSelectViewResult]
public ViewResultBase AndDoThisLikeSo(){
//controller action logic
}
I think overall this will be a much better solution than coupling these two functionalities to an ActionResult.

How to specify the location a Mvc view will be created for a Mvc controller?

Important Update
Since the release of MVC 2.0 Preview 1 this feature has been implemented as the part of the actual framework itself in the form of Areas. More details available on Phil Haack's blog here
I have a controller called ListManagerController. This controller contain an ActionResult method called Index(). When I right cick on Index in Visual Studio and select Add View the new view is created in /Views/ListManager/Index.
However I want the Index view and all subsequent views to be created in /Views/Manage/ListManager/. How would I accomplish this?
Edit: It was pointed out that this question is a duplicate of the question posted here. It seems my searching skills failed me initially.
The location of views is tied to the ViewFactory you are using. AFAIK the web forms view engines does not support areas [Manage in your example].
Spark supports this and is very clean, you can also mix and match web forms and spark views so you don't have to recreate all your views.
UPDATE: Looks like Phil Haack has a blog post on how to achieve this. His code is for the RC, but I think that should compile fine against ASP.NET MVC RTM.
I know you already accepted an answer but here's what I came up with while experimenting with the same idea, with the help of Phil Haack's post.
First you need to have your own ViewEngine to look for folders under View folder. Something like this : (You'll notice that it looks a lot like Phil Haack's areas code)
public class TestViewEngine : WebFormViewEngine
{
public TestViewEngine()
: base()
{
MasterLocationFormats = new[] {
"~/Views/{1}/{0}.master",
"~/Views/Shared/{0}.master"
};
ViewLocationFormats = new[] {
"~/{0}.aspx",
"~/{0}.ascx",
"~/Views/{1}/{0}.aspx",
"~/Views/{1}/{0}.ascx",
"~/Views/Shared/{0}.aspx",
"~/Views/Shared/{0}.ascx"
};
PartialViewLocationFormats = ViewLocationFormats;
}
public override ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName, bool useCache)
{
ViewEngineResult rootResult = null;
//if the route data has a root value defined when mapping routes in global.asax
if (controllerContext.RouteData.Values.ContainsKey("root")) {
//then try to find the view in the folder name defined in that route
string rootViewName = FormatViewName(controllerContext, viewName);
rootResult = base.FindView(controllerContext, rootViewName, masterName, useCache);
if (rootResult != null && rootResult.View != null) {
return rootResult;
}
//same if it's a shared view
string sharedRootViewName = FormatSharedViewName(controllerContext, viewName);
rootResult = base.FindView(controllerContext, sharedRootViewName, masterName, useCache);
if (rootResult != null && rootResult.View != null) {
return rootResult;
}
}
//if not let the base handle it
return base.FindView(controllerContext, viewName, masterName, useCache);
}
private static string FormatViewName(ControllerContext controllerContext, string viewName) {
string controllerName = controllerContext.RouteData.GetRequiredString("controller");
string root = controllerContext.RouteData.Values["root"].ToString();
return "Views/" + root + "/" + controllerName + "/" + viewName;
}
private static string FormatSharedViewName(ControllerContext controllerContext, string viewName) {
string root = controllerContext.RouteData.Values["root"].ToString();
return "Views/" + root + "/Shared/" + viewName;
}
}
Then in your Global.asax replace the default ViewEngine with your custom one, on Application_Start :
ViewEngines.Engines.Clear();
ViewEngines.Engines.Add(new TestViewEngine());
Now when you are defining routes in Global.asax, you need to set a root value indicating the folder to look for under the View folders like so :
routes.MapRoute(
"ListManager",
"ListManager/{action}/{id}",
new { controller = "ListManager", action = "Index", id = "", root = "Manage" }
);
This question is VERY much a repeat of this question
so I'll quote my answer to that one here.
I came up with a different solution
that didn't require me to roll my own
view engine.
Basically, I wanted to keep MVC as
"Convention" driven as possible, but I
still wanted to organize all of my
"Admin" views under the ~/Views/Admin
folder.
Example:
~/Views/Admin/User/
~/Views/Admin/News/
~/Views/Admin/Blog/
My solution was to create a new base
class for my specific admin
controllers and "force" the path to
the view for that controller.
I have a blog post and sample code
here: Organize your views in ASP.Net
MVC

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