Understanding the execution flow
We've introduced many building blocks and their descriptions, as well as how these building blocks are placed in layers in a .NET solution. In this section, we will explore how an HTTP request is executed in a typical web application that has been layered based on DDD. The following diagram shows the layers in action:
Figure 9.14 – Execution flow through the layers
A request starts with a request from a client application. The client can be a browser that expects an HTML page (with its CSS/JavaScript files) or a data result (such as JSON). In this case, a Razor Page can process the request and returns an HTML page. If the application making the request is another kind of client (such as a console application), you probably respond to the request from an HTTP API (an API controller) endpoint and return a plain data result.
The MVC page (in the presentation layer) processes the UI logic, may perform some data conversions...
