C# – How to get an ASP.NET MVC Ajax response to redirect to new page instead of inserting view into UpdateTargetId

ajaxasp.net-mvcasp.net-mvc-ajaxc

I am using the Ajax.BeginForm to create a form the will do an ajax postback to a certain controller action and then if the action is successful, the user should get redirected to another page (if the action fails then a status message gets displayed using the AjaxOptions UpdateTargetId).

using (Ajax.BeginForm("Delete", null,
        new { userId = Model.UserId },
        new AjaxOptions { UpdateTargetId = "UserForm", LoadingElementId = "DeletingDiv" },
        new { name = "DeleteForm", id = "DeleteForm" }))
   {
    [HTML DELETE BUTTON]
   }

If the delete is successful I am returning a Redirect result:

[Authorize]
public ActionResult Delete(Int32 UserId)
{
    UserRepository.DeleteUser(UserId);
    return Redirect(Url.Action("Index", "Home"));
}

But the Home Controller Index view is getting loaded into the UpdateTargetId and therefore I end up with a page within a page. Two things I am thinking about:

Either I am architecting this
wrong and should handle this type of
action differently (not using ajax).
Instead of returning a Redirect
result, return a view which has
javascript in it that does the
redirect on the client side.

Does anyone have comments on #1? Or if #2 is a good solution, what would the "redirect javascript view" look like?

Best Answer

You can use JavascriptResult to achieve this.

To redirect:

return JavaScript("window.location = 'http://www.google.co.uk'");

To reload the current page:

return JavaScript("location.reload(true)");

Seems the simplest option.

Related Solutions

Asp.net-mvc – How to render an ASP.NET MVC view as a string

Here's what I came up with, and it's working for me. I added the following method(s) to my controller base class. (You can always make these static methods somewhere else that accept a controller as a parameter I suppose)

MVC2 .ascx style

protected string RenderViewToString<T>(string viewPath, T model) {
  ViewData.Model = model;
  using (var writer = new StringWriter()) {
    var view = new WebFormView(ControllerContext, viewPath);
    var vdd = new ViewDataDictionary<T>(model);
    var viewCxt = new ViewContext(ControllerContext, view, vdd,
                                new TempDataDictionary(), writer);
    viewCxt.View.Render(viewCxt, writer);
    return writer.ToString();
  }
}

Razor .cshtml style

public string RenderRazorViewToString(string viewName, object model)
{
  ViewData.Model = model;
  using (var sw = new StringWriter())
  {
    var viewResult = ViewEngines.Engines.FindPartialView(ControllerContext,
                                                             viewName);
    var viewContext = new ViewContext(ControllerContext, viewResult.View,
                                 ViewData, TempData, sw);
    viewResult.View.Render(viewContext, sw);
    viewResult.ViewEngine.ReleaseView(ControllerContext, viewResult.View);
    return sw.GetStringBuilder().ToString();
  }
}

Edit: added Razor code.

Asp.net-mvc – How to get ELMAH to work with ASP.NET MVC [HandleError] attribute

You can subclass HandleErrorAttribute and override its OnException member (no need to copy) so that it logs the exception with ELMAH and only if the base implementation handles it. The minimal amount of code you need is as follows:

using System.Web.Mvc;
using Elmah;

public class HandleErrorAttribute : System.Web.Mvc.HandleErrorAttribute
{
    public override void OnException(ExceptionContext context)
    {
        base.OnException(context);
        if (!context.ExceptionHandled) 
            return;
        var httpContext = context.HttpContext.ApplicationInstance.Context;
        var signal = ErrorSignal.FromContext(httpContext);
        signal.Raise(context.Exception, httpContext);
    }
}

The base implementation is invoked first, giving it a chance to mark the exception as being handled. Only then is the exception signaled. The above code is simple and may cause issues if used in an environment where the HttpContext may not be available, such as testing. As a result, you will want code that is that is more defensive (at the cost of being slightly longer):

using System.Web;
using System.Web.Mvc;
using Elmah;

public class HandleErrorAttribute : System.Web.Mvc.HandleErrorAttribute
{
    public override void OnException(ExceptionContext context)
    {
        base.OnException(context);
        if (!context.ExceptionHandled       // if unhandled, will be logged anyhow
            || TryRaiseErrorSignal(context) // prefer signaling, if possible
            || IsFiltered(context))         // filtered?
            return;

        LogException(context);
    }

    private static bool TryRaiseErrorSignal(ExceptionContext context)
    {
        var httpContext = GetHttpContextImpl(context.HttpContext);
        if (httpContext == null)
            return false;
        var signal = ErrorSignal.FromContext(httpContext);
        if (signal == null)
            return false;
        signal.Raise(context.Exception, httpContext);
        return true;
    }

    private static bool IsFiltered(ExceptionContext context)
    {
        var config = context.HttpContext.GetSection("elmah/errorFilter")
                        as ErrorFilterConfiguration;

        if (config == null)
            return false;

        var testContext = new ErrorFilterModule.AssertionHelperContext(
                              context.Exception, 
                              GetHttpContextImpl(context.HttpContext));
        return config.Assertion.Test(testContext);
    }

    private static void LogException(ExceptionContext context)
    {
        var httpContext = GetHttpContextImpl(context.HttpContext);
        var error = new Error(context.Exception, httpContext);
        ErrorLog.GetDefault(httpContext).Log(error);
    }

    private static HttpContext GetHttpContextImpl(HttpContextBase context)
    {
        return context.ApplicationInstance.Context;
    }
}

This second version will try to use error signaling from ELMAH first, which involves the fully configured pipeline like logging, mailing, filtering and what have you. Failing that, it attempts to see whether the error should be filtered. If not, the error is simply logged. This implementation does not handle mail notifications. If the exception can be signaled then a mail will be sent if configured to do so.

You may also have to take care that if multiple HandleErrorAttribute instances are in effect then duplicate logging does not occur, but the above two examples should get your started.

Best Answer

Related Solutions

Asp.net-mvc – How to render an ASP.NET MVC view as a string

Asp.net-mvc – How to get ELMAH to work with ASP.NET MVC [HandleError] attribute

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