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 and using a result filter


In this recipe, you will learn how to create and use a result filter.

Getting ready

Let's create an empty web application with VS 2017.

How to do it...

A result filter injects treatment before or after the result is executed. It could check and modify the result generated by action methods.

Some common result filter implementations could be adding or checking headers, and many others.

To create our own result filter, we have to create a class that derives from any of the following base classes or interfaces:

  • IResultFilter or IAsyncResultFilter, depending on whether we want to create a synchronous or an asynchronous filter
  • ResultFilterAttribute

As with IActionResult/IAsyncActionResult interfaces, IResultFilter and IResultActionFilter inherit from IFilterMetadata. All the classes implemented in those interfaces can't use an attribute above a controller or action method. A class should implement IResultFilter, or IResultActionFilter and TypeFilter, or ServiceFilter...