Routes values are being added in duplicate

[mdmoura]

Hello,

I created a TagHelper and needed to access the current route so I ended up with:

    [TargetElement("a", Attributes = RouteHasName)]
    public class RouteActiveTagHelper : TagHelper {

      private const String RouteHasName = "route-has";

      private IActionContextAccessor _actionContextAccessor;
      private IUrlHelper _urlHelper;   

      [HtmlAttributeName(RouteHasName)]
      public String RouteHas { get; set; }

      public RouteActiveTagHelper(IActionContextAccessor actionContextAccessor, IUrlHelper urlHelper) {
        _actionContextAccessor = actionContextAccessor;
        _urlHelper = urlHelper;
    } // RouteActiveTagHelper

    public override void Process(TagHelperContext context, TagHelperOutput output) {

      var values = _actionContextAccessor.ActionContext.RouteData.Values;

      String route = _urlHelper.RouteUrl(values.Distinct());  

      // Removed remaining code for sake of simplicity

      } // Process
    } // RouteActiveTagHelper

When I create the route I get the error "ArgumentException: An item with the same key has already been added." on every route which is defined using Attribute Routing.

To fix this I needed to apply Distinct to values before creating a route.

Is there any reason for having duplicated objects in route values? Is this a bug?

If this is the expected result is there a better way to get the current route values?

Note: I get the same error using ViewContext ...

Thank You,
Miguel

[rynowak]

This seems like a bug. Can you include a callstack for the exception?

As a workaround, if you're just trying to link to the 'current values' you don't need to pass them in to RouteUrl.

_urlHelper.RouteUrl(new { })

[mdmoura]

Here is the stack. Does it help?

    ArgumentException: An item with the same key has already been added.
        System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
            System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
            System.Collections.Generic.Dictionary`2.Add(TKey key, TValue value)
            Microsoft.AspNet.Mvc.Routing.InnerAttributeRoute.GenerateVirtualPath(VirtualPathContext context, AttributeRouteLinkGenerationEntry entry)
            Microsoft.AspNet.Mvc.Routing.InnerAttributeRoute.GetVirtualPath(VirtualPathContext context)
            Microsoft.AspNet.Mvc.Routing.AttributeRoute.GetVirtualPath(VirtualPathContext context)
            Microsoft.AspNet.Routing.RouteCollection.GetVirtualPath(VirtualPathContext context)
            Microsoft.AspNet.Mvc.UrlHelper.GeneratePathFromRoute(String routeName, IDictionary`2 values)
            Microsoft.AspNet.Mvc.UrlHelper.RouteUrl(UrlRouteContext routeContext)
            Microsoft.AspNet.Mvc.UrlHelperExtensions.RouteUrl(IUrlHelper helper, String routeName, Object values, String protocol, String host, String fragment)
            Microsoft.AspNet.Mvc.UrlHelperExtensions.RouteUrl(IUrlHelper helper, Object values)
            MvcProject.Web.ActiveRouteTagHelper.Process(TagHelperContext context, TagHelperOutput output) in ActiveRouteTagHelper.cs
      public override void Process(TagHelperContext context, TagHelperOutput output) {
        IDictionary<String, Object> values = _actionContextAccessor.ActionContext.RouteData.Values;
        String route = _urlHelper.RouteUrl(values).ToLowerInvariant();
        Boolean match = false;
        if (!String.IsNullOrWhiteSpace(RouteIs)) {
            match = route == RouteIs;
            Microsoft.AspNet.Razor.Runtime.TagHelpers.TagHelper.< ProcessAsync > d__4.MoveNext()
            -- End of stack trace from previous location where exception was thrown ---
            System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
                System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
                System.Runtime.CompilerServices.TaskAwaiter.GetResult()
                Microsoft.AspNet.Razor.Runtime.TagHelpers.TagHelperRunner.< RunAsync > d__0.MoveNext()
    -- End of stack trace from previous location where exception was thrown ---
    System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
        System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
        System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
        Asp.ASPV__Views_Shared__Prime_Main_cshtml.<> c__DisplayClass28_0.<< ExecuteAsync > b__0 > d.MoveNext() in _Prime.Main.cshtml
                                            }
    ---End of stack trace from previous location where exception was thrown ---
    System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
        System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
        System.Runtime.CompilerServices.TaskAwaiter.GetResult()
        Microsoft.AspNet.Mvc.Razor.RazorPage.< RenderSectionAsyncCore > d__93.MoveNext()
        -- - End of stack trace from previous location where exception was thrown ---
            System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
        System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
        System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
        Microsoft.AspNet.Mvc.Razor.RazorPage.RenderSection(String name, Boolean required)
        Asp.ASPV__Views_Shared__Prime_cshtml.<< ExecuteAsync > b__21_0 > d.MoveNext() in _Prime.cshtml
            @RenderSection("Body", required: true)
            ---End of stack trace from previous location where exception was thrown ---
            System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            Microsoft.AspNet.Mvc.Razor.RazorPage.< RenderSectionAsyncCore > d__93.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
            Microsoft.AspNet.Mvc.Razor.RazorPage.RenderSection(String name, Boolean required)
            Asp.ASPV__Views_Shared__Empty_cshtml.< ExecuteAsync > d__29.MoveNext() in _Empty.cshtml
                @RenderSection("Body", required: true)
            ---End of stack trace from previous location where exception was thrown ---
            System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            Microsoft.AspNet.Mvc.Razor.RazorView.< RenderPageCoreAsync > d__17.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            Microsoft.AspNet.Mvc.Razor.RazorView.< RenderPageAsync > d__16.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
            Microsoft.AspNet.Mvc.Razor.RazorView.< RenderLayoutAsync > d__19.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            Microsoft.AspNet.Mvc.Razor.RazorView.< RenderAsync > d__15.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            Microsoft.AspNet.Mvc.ViewExecutor.< ExecuteAsync > d__1.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            Microsoft.AspNet.Mvc.ViewResult.< ExecuteResultAsync > d__24.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            Microsoft.AspNet.Mvc.Core.FilterActionInvoker.< InvokeResultAsync > d__53.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            Microsoft.AspNet.Mvc.Core.FilterActionInvoker.< InvokeResultFilterAsync > d__52.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
            Microsoft.AspNet.Mvc.Core.FilterActionInvoker.< InvokeAllResultFiltersAsync > d__51.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            Microsoft.AspNet.Mvc.Core.FilterActionInvoker.< InvokeResourceFilterAsync > d__46.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
            Microsoft.AspNet.Mvc.Core.FilterActionInvoker.< InvokeAsync > d__41.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            Microsoft.AspNet.Mvc.MvcRouteHandler.< InvokeActionAsync > d__7.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            Microsoft.AspNet.Mvc.MvcRouteHandler.< RouteAsync > d__6.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            Microsoft.AspNet.Mvc.Routing.InnerAttributeRoute.< RouteAsync > d__10.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            Microsoft.AspNet.Routing.RouteCollection.< RouteAsync > d__9.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            Microsoft.AspNet.Builder.RouterMiddleware.< Invoke > d__4.MoveNext()
            -- - End of stack trace from previous location where exception was thrown ---
                System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            Microsoft.AspNet.Diagnostics.ErrorPageMiddleware.< Invoke > d__6.MoveNext()

[rynowak]

Thanks, that will help us narrow it down.