How to add a subroute in controller method-CodePudding

I've created a controller class:

[Route("api/[controller]")]
[ApiController]
public class CourseController : ControllerBase

I've got methods for the route declared in the attribute above but I also want to handle a subroute, eg. "api/[controller]/{id}/course_subjects". I've tried adding the Route attribute to the method but after running the application I see a Swagger error and no response from that route when I type it in the browser.

The method:

[HttpGet("{id}")]
public async Task<IEnumerable<SubjectDto>> GetCourseSubjectsList(string courseId)
{
    return await _courseProcessor.GetSubjectsForCourseAsync(courseId);
}

This is how I add the Route

[HttpGet("{id}")]
[Route("api/[controller]/{id}/course_subjects/")]
public async Task<IEnumerable<SubjectDto>> GetCourseSubjectsList(string courseId)
{
    return await _courseProcessor.GetSubjectsForCourseAsync(courseId);
}

If I add the route directly in the HttpGet attribute, I get an error about the parameter being missing.

[HttpGet("{id}/course_subjects")]
public async Task<IEnumerable<SubjectDto>> GetCourseSubjectsList(string courseId)
{
    return await _courseProcessor.GetSubjectsForCourseAsync(courseId);
}

The error in the browser:

type    "https://tools.ietf.org/html/rfc7231#section-6.5.1"
title   "One or more validation errors occurred."
status  400
traceId "00-9c0f1c8198ed9573148cd3628c358ee3-87d7adc13bc3db77-00"
errors  
courseId    
0   "The courseId field is required."

What am I doing wrong?

CodePudding user response：

you do not need Route attribute at all. You can specify the route in the HttpGet

[HttpGet("{id}/course_subjects")]

CodePudding user response：

I figured it out. When I used the subroute in the HttpGet attribute, I didn't use a matching parameter name for the attribute and the method argument. In the attribute I used id and in the method argument I used courseId.

So the code should be:

[HttpGet("{id}/course_subjects")]
public async Task<IEnumerable<SubjectDto>> GetCourseSubjectsList(string id)
{
    return await _courseProcessor.GetSubjectsForCourseAsync(id);
}