Automatically generate calls to SwaggerDoc in Swagger - asp.net-core

Question

public void ConfigureServices(IServiceCollection services)
{
services.AddControllers(); //this replaces these services.AddMvcCore().AddApiExplorer();
...
services.AddSwaggerGen(options =>
{
// make this automatic ???
options.SwaggerDoc("v1", new Info { Version = "v1", Title = "v1 API", Description = "v1 API Description" });
options.SwaggerDoc("v2", new Info { Version = "v2", Title = "v2 API", Description = "v2 API Description" });
...
options.DocInclusionPredicate((version, desc) =>
{
var versions = desc.CustomAttributes().OfType<ApiVersionAttribute>().SelectMany(attr => attr.Versions).ToArray();
var maps = desc.CustomAttributes().OfType<MapToApiVersionAttribute>().SelectMany(attr => attr.Versions).ToArray();
return versions.Any(v => $"v{v.ToString()}" == version) && (!maps.Any() || maps.Any(v => $"v{v.ToString()}" == version));
});
});
}
This code works as expected. But can the calls to SwaggerDoc be automated, in order to make the code more generic? In DocInclusionPredicate from the desc parameter the versions can be gathered.

Answer 1

As you are using the ApiVersionAttribute, I assume you are using the Microsoft.AspNetCore.Mvc.Versioning nuget package. The package provides a service named IApiVersionDescriptionProvider. This service provides an enumeration of all detected API-Versions. You can then automatically add them as a swagger-doc.
services.AddSwaggerGen(options =>
{
// you can use the IApiVersionDescriptionProvider
var provider = services.BuildServiceProvider()
.GetRequiredService<IApiVersionDescriptionProvider>();
foreach (var description in provider.ApiVersionDescriptions)
{
var info = new Info
{
Title = $"My API {description.ApiVersion}",
Version = description.ApiVersion.ToString(),
Contact = new Contact
{
Email = "info#mydomain.com",
Name = "Foo Bar",
Url = "https://thecatapi.com/"
}
};
options.SwaggerDoc(description.GroupName, info);
}
// instead of manually adding your versions
//options.SwaggerDoc("v1", new Info { Version = "v1", Title = "v1 API", Description = "v1 API Description" });
//options.SwaggerDoc("v2", new Info { Version = "v2", Title = "v2 API", Description = "v2 API Description" });
options.DocInclusionPredicate((version, desc) =>
{
var versions = desc.CustomAttributes().OfType<ApiVersionAttribute>().SelectMany(attr => attr.Versions).ToArray();
var maps = desc.CustomAttributes().OfType<MapToApiVersionAttribute>().SelectMany(attr => attr.Versions).ToArray();
return versions.Any(v => $"v{v.ToString()}" == version) && (!maps.Any() || maps.Any(v => $"v{v.ToString()}" == version));
});
});