Book Image

Metaprogramming in C#

By : Einar Ingebrigtsen
Book Image

Metaprogramming in C#

By: Einar Ingebrigtsen

Overview of this book

Metaprogramming is an advanced technique that helps developers to automate repetitive tasks, generate scalable code, and enhance productivity in software development. Metaprogramming in C# is a comprehensive guide that will help you reap the full potential of metaprogramming in .NET runtime. You’ll start by learning about the .NET runtime environment and how you can use it to become a more productive developer. You'll learn how to infer types using reflection, use attributes, and create dynamic proxies. You’ll also explore the use of expressions to create and execute code and how to take advantage of Dynamic Language Runtime. But that's not all! You’ll also learn to go beyond inheritance and use method signature conventions to create easily maintainable code. Finally, you’ll dive into the world of compiler magic with Roslyn, where you'll discover how to use Roslyn to generate code, perform static code analysis, and write your own compiler extensions. By the end of this book, you’ll have a deep understanding of metaprogramming concepts and how to apply them to your C# code. You’ll be able to think about types, use attributes and expressions to generate code, and apply crosscutting concerns to improve code quality.
Table of Contents (25 chapters)
1
Part 1:Why Metaprogramming?
5
Part 2:Leveraging the Runtime
12
Part 3:Increasing Productivity, Consistency, and Quality
18
Part 4:Compiler Magic Using Roslyn

ASP.NET validation

When doing HTTP requests against ASP.NET, it goes through a pipeline consisting of different middlewares with specific responsibilities. This pipeline is completely configurable and extensible by you as a developer. Out of the box, it comes pre-configured with a specific middleware that handles the validation of objects sent to a request. The validation engine behind this recognizes rules in the form of metadata that can be applied to the objects. This metadata again is based on C# attributes.

Let’s start by changing our Employee object a bit. Open the Employee.cs file and make it look like the following:

public record Employee(
    [Required]
    string FirstName,
    [Required]
    string LastName);

This makes the FirstName and LastName properties required by adding the [Required] attribute to them. The ASP.NET pipeline will pick this up and check any input being sent...