Aspnetcore: Asp .Net Core Tag not rendering from a Custom tag helper

[jfcaldeira]

Here is my custom tag helper, it renders asp-for as asp-page on browser.... Is there a way i need to refer other tag helpers cuase this way it is not rendering

    [HtmlTargetElement("card")]
    public class CardTagHelper : TagHelper
    {
        public string Title { get; set; }
        public string Icon { get; set; }
        public string Url { get; set; }

        public override void Process(TagHelperContext context, TagHelperOutput output)
        {
            output.TagName = "CardTagHelper";
            output.TagMode = TagMode.StartTagAndEndTag;

            var preContent = new StringBuilder();
            preContent.AppendFormat($@"
                    <div class='card custom-card'>
                        <div class='card-header'>
                            <div class='card-title'>");

            if (Url != null)
            {
                preContent.AppendFormat($@"
                                <a asp-page='{Url}'>
                                    <div class='float-left return'>
                                        <i class='fas fa-arrow-alt-circle-left fa-lg'></i>
                                    </div>
                                </a>");
            }

preContent.AppendFormat($@"<i class='{Icon}'></i>
                                {Title}
                            </div>
                        </div>
                        <div class='card-body'>");

            var postContent = new StringBuilder();
            postContent.AppendFormat($@"                                   
                        </div>
                        <div class='card-footer'>
                        </div>
                    </div>");

            output.PreContent.SetHtmlContent(preContent.ToString());
            output.PostContent.SetHtmlContent(postContent.ToString());
        }
    }
}

This is my view import, i changed the order so my custom tag helper was first but didnt change anything

@using MyProject
@namespace MyProject.Pages
@addTagHelper *, MyProject
@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers

[mkArtakMSFT]

Hi. It looks like this is a question about how to use ASP.NET Core. While we do our best to look through all the issues filed here, to get a faster response we suggest posting your questions to StackOverflow using the asp.net-core-mvc tag.

[mkArtakMSFT]

FYI: You're trying to embed a razor content in the output of the Tag Helper, and that's not supported.

[jfcaldeira]

FYI: You're trying to embed a razor content in the output of the Tag Helper, and that's not supported.

I see, so there is no workaround for this? I have just been feeding it @Url.Page(""), it does the job but would rather have to just right the path "./Index" or "../Index"

[mkArtakMSFT]

You can simply use the Razor content you have in this tag helper instead of it, wherever you reference it.

[mkArtakMSFT]

Seems like you're just trying to have a reusable razor component - what about using Partial Views for it?

[jfcaldeira]

You can simply use the Razor content you have in this tag helper instead of it, wherever you reference it.

Could you show me an example please? I tried add asp-page on it and didn't do anything

[mkArtakMSFT]

Here is the docs article about PartialViews: https://docs.microsoft.com/en-us/aspnet/core/mvc/views/partial?view=aspnetcore-2.2
It does contain an example too

[jfcaldeira]

Here is the docs article about PartialViews: https://docs.microsoft.com/en-us/aspnet/core/mvc/views/partial?view=aspnetcore-2.2
It does contain an example too

I don't think partial views will help me in this situation because i need to write content inside, html razor etc...

something i can use in every page as a container for my content

[mkArtakMSFT]

Think about PartialViews as reusable views, which can contain both html and razor content. You can then use the Partial Tag Helper to reference them from different pages/views.