Book Image

ASP.NET Core MVC 2.0 Cookbook

By : Jason De Oliveira, Engin Polat, Stephane Belkheraz
Book Image

ASP.NET Core MVC 2.0 Cookbook

By: Jason De Oliveira, Engin Polat, Stephane Belkheraz

Overview of this book

The ASP.NET Core 2.0 Framework has been designed to meet all the needs of today’s web developers. It provides better control, support for test-driven development, and cleaner code. Moreover, it’s lightweight and allows you to run apps on Windows, OSX and Linux, making it the most popular web framework with modern day developers. This book takes a unique approach to web development, using real-world examples to guide you through problems with ASP.NET Core 2.0 web applications. It covers Visual Studio 2017- and ASP.NET Core 2.0-specifc changes and provides general MVC development recipes. It explores setting up .NET Core, Visual Studio 2017, Node.js modules, and NuGet. Next, it shows you how to work with Inversion of Control data pattern and caching. We explore everyday ASP.NET Core MVC 2.0 patterns and go beyond it into troubleshooting. Finally, we lead you through migrating, hosting, and deploying your code. By the end of the book, you’ll not only have explored every aspect of ASP.NET Core MVC 2.0, you’ll also have a reference you can keep coming back to whenever you need to get the job done.
Table of Contents (26 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Creating TagHelpers programmatically


In this recipe, we will learn how to create a TagHelper programmatically to display a menu bar.

Getting ready

We create an empty web application, adding Microsoft.AspNetCore.Mvc in project.json. We also create a controller class with an Index View.

How to do it...

It's relatively easy to create a custom TagHelper in C# and use it inside a CSHTML view.

  1. First, let's create a VerticalMenuTagHelper class, which inherits from TagHelper. We indicate, by using the HtmlTargetElement attribute above the class, that we will use vmenu as the HTML element name to use this TagHelper in a view :
namespace R3.TagHelpers 
{ 
  [HtmlTargetElement("vmenu")] 
  public class VerticalMenuTagHelper : TagHelper 
  { 
    public List<MenuElement> Elements { get; set; } 
    public override void Process( 
    TagHelperContext context, TagHelperOutput output) 
    { 
      output.TagName = "section"; 
      string menuElements = "<ul>"; 
      foreach (var e in Elements...