Swagger doc has empty paths - asp.net-core

Question

My Swagger document is not properly generated, I have the basic information (title, name, licence etc) but no doc on my routes.
Here's the setup in Startup.cs :
public void ConfigureServices(IServiceCollection services)
{
services.AddDbContext<APIContext>(options => options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));
services.AddControllersWithViews();
services.AddSwaggerGen(c =>
{
c.SwaggerDoc("v1", new OpenApiInfo
{
Version = "v1",
Title = "OpenWeb Challenge",
Description = "A 'simple' example ASP.NET Core Web API",
TermsOfService = new Uri("https://example.com/terms"),
Contact = new OpenApiContact
{
Name = "Anthony Da Silva Ferreira",
Email = string.Empty,
Url = new Uri("https://twitter.com/spboyer"),
}
});
var xmlFile = $"{Assembly.GetExecutingAssembly().GetName().Name}.xml";
var xmlPath = Path.Combine(AppContext.BaseDirectory, xmlFile);
c.IncludeXmlComments(xmlPath);
});
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
app.UseSwagger();
app.UseSwaggerUI(c =>
{
c.SwaggerEndpoint("/swagger/v1/swagger.json", "OpenWebChallenge V1");
});
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllerRoute(name: "default",pattern: "{controller=Home}/{action=Index}/{id?}");
});
}
And the content of the swagger :
{
"openapi": "3.0.1",
"info": {
"title": "OpenWeb Challenge",
"description": "A 'simple' example ASP.NET Core Web API",
"termsOfService": "https://example.com/terms",
"contact": {
"name": "Anthony Da Silva Ferreira",
"url": "https://twitter.com/spboyer",
"email": ""
},
"license": {
"name": "Licence",
"url": "https://example.com/license"
},
"version": "v1"
},
"paths": { },
"components": { }
}
Controller sample :
public class ContactsController : Controller
{
private readonly APIContext _context;
public ContactsController(APIContext context)
{
_context = context;
}
// GET: Contacts
public async Task<IActionResult> Index()
{
return View(await _context.Contacts.ToListAsync());
}
// GET: Contacts/Details/5
public async Task<IActionResult> Details(int? id)
{
if (id == null)
{
return NotFound();
}
var contact = await _context.Contacts
.Include(c => c.ContactSkills)
.ThenInclude(cs => cs.Skill)
.AsNoTracking()
.FirstOrDefaultAsync(m => m.Id == id);
if (contact == null)
{
return NotFound();
}
return View(contact);
}
}
Am I missing any configuration or something? It's my first time creating API from scratch.

Answer 1

Have you added the PropertyGroup to the PROJECT_NAME.csproj file?
<PropertyGroup>
<GenerateDocumentationFile>true</GenerateDocumentationFile>
<NoWarn>$(NoWarn);1591</NoWarn>
</PropertyGroup>
Without it the compiler will not generate the documentation file.
Microsoft Documentation
edit
in the documentation it says: "You must use attribute routing for any controllers that you want represented in your Swagger document(s)" Link.
so for your controller it would be:
[Route("api/contacts")]
public class ContactsController : Controller
{
...
// GET: Contacts
[HttpGet("")]
public async Task<IActionResult> Index()
{
...
}
// GET: Contacts/Details/5
[HttpGet("/details/{id?}")]
public async Task<IActionResult> Details([FromRoute] int? id)
{
...
}
}
edit
i used wrong route template syntax:
[HttpGet("/details/:id?")] -> [HttpGet("/details/{id?}")]
? for optional parameter

Answer 2

From your code, the ContactsController seems like a MVC controller (it will return views), instead of API controller.
The Swagger (OpenAPI) is a language-agnostic specification for describing REST APIs, instead of MVC Controller. So, it will not generate Swagger document for the MVC controller. Try to add a API controller, then, add API info and description using Swagger.
More details information about using Swagger, check Get started with Swashbuckle and ASP.NET Core