Create API Controller

Create a controller for a given entity in an ASP.NET Core Web API project.

Pre-requisites

• Use Controller-based APIs
• Use System.Text.Json for all JSON data
• The project uses Entity Framework Core 9 — do not install additional packages, the project is already set up.

Steps

1. Create an empty controller with the naming rule: {EntityName}Controller

2. Set up DI and inject Entity Framework context and ILogger<T>.

3. Do not use Entity Class for model binding. Create DTO classes for each CRUD operation instead.

4. Add CRUD REST API methods with required OpenAPI-related annotations.

5. Add OperationId to each action method. Example:

   // Before
   [HttpGet]
   
   // After
   [HttpGet(Name = "GetCourses")]

   Give each OperationId a meaningful name.

6. Apply [ProducesResponseType] attribute to each action reflecting API behavior.

7. Edit coursemanagement.http for testing:

   • Do not touch the existing @HostAddress variable definition.
   • Use the HostAddress variable.
   • Reference related Entity Class for test payloads.
   • When writing POST method, don't add Primary Key from the entity.

8. Run dotnet build to verify everything compiles.

9. Add Swashbuckle.AspNetCore.SwaggerUI package:

   dotnet add package Swashbuckle.AspNetCore.SwaggerUI

10. Add the following code to Program.cs:

    app.UseSwaggerUI(options =>
    {
        options.SwaggerEndpoint("/openapi/v1.json", "OpenAPI V1");
    });

11. Run dotnet run to verify the application starts successfully.