Custom tag helper not working

Question

I followed a few guides on creating a custom tag helper for ASP Core.

This is my helper:

using Microsoft.AspNetCore.Mvc.ViewFeatures; using Microsoft.AspNetCore.Razor.TagHelpers; using System;  namespace ToolControlSystem.TagHelpers {     [HtmlTargetElement("description", Attributes = DescriptionAttributeName, TagStructure = TagStructure.NormalOrSelfClosing)]     public class DescriptionTagHelper : TagHelper     {         private const string DescriptionAttributeName = "asp-for";           [HtmlAttributeName(DescriptionAttributeName)]         public ModelExpression Model { get; set; }          public override void Process(TagHelperContext context, TagHelperOutput output)         {             base.Process(context, output);              var description = GetDescription(Model.ModelExplorer);              output.TagName = "span";             output.TagMode = TagMode.StartTagAndEndTag;             output.Content.SetContent(description);         }          private string GetDescription(ModelExplorer modelExplorer)         {             string description;             description = modelExplorer.Metadata.Placeholder;              if (String.IsNullOrWhiteSpace(description))             {                 description = modelExplorer.Metadata.Description;             }              return description;         }     } } 

I drop this in _ViewImports.cshtml: @addTagHelper *, ToolConstrolSystem.TagHelpers

Annnndd... nothing. No intellisense, no tag replacing...

Any ideas?

Answer 1

You need to provide only assembly name in the view imports file.

_ViewImports.cshtml:

@addTagHelper *, ToolConstrolSystem 

Answer 2

See Managing Tag Helper scope

@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers @addTagHelper *, AuthoringTagHelpers 

The code above uses the wildcard syntax (*) to specify that all Tag Helpers in the specified assembly (Microsoft.AspNetCore.Mvc.TagHelpers) will be available to every view file in the Views directory or sub-directory.