Creating a Bootstrap Alert Tag Helper

To create a Bootstrap Alert Tag Helper, which will be a little bit more advanced than the previous example, follow these steps:

1. Create a new class called BootstrapAlertTagHelper in the TagHelpers folder.

2. Change the class to inherit from TagHelper.

3. Add a Boolean property called Dismissable and a string property called Color to the class:

            public bool Dismissable { get; set; } 
           public string Color { get; set; } 
   

4. Next, override the ProcessAsync method, as illustrated here:

           public override async Task ProcessAsync(TagHelperContext context, 
          TagHelperOutput output) 
           { 
               output.TagName = "div"; 
               output.Attributes.Add("class","alert alert-" + Color); 
               output.Attributes.Add("role", "attribute"); 
               if (Dismissable) 
                   output.PostContent.SetHtmlContent( 
               $"<button type="button" class="close" data-dismiss="alert">
               <span aria-hidden="true...