Swashbuckle ASP.NET Versioning Shim

This library aids the use of Swashbuckle and ASP NET Web API Versioning together and started from my attempt at resolving Swashbuckle.AspNetCore issue 244

Getting started

• Start by creating a new ASP.NET Core Web Application
• Install the SwashbuckleAspNetVersioningShim NuGet package from
  • Source or Releases
  • MyGet
  • NuGet
• Add the following code blocks to Startup.cs

using Microsoft.AspNetCore.Mvc.ApiExplorer;
using SwashbuckleAspNetVersioningShim;

public void ConfigureServices(IServiceCollection services)
{
    services.AddMvc();
    services.AddMvcCore().AddVersionedApiExplorer();
    services.AddApiVersioning();
    services.AddSwaggerGen(c => {
        var provider = services.BuildServiceProvider().GetRequiredService<IApiVersionDescriptionProvider>();
        c.ConfigureSwaggerVersions(provider);
    });
    ...

//Note the change of method signature to include injection of IApiVersionDescriptionProvider
public void Configure(IApplicationBuilder app, IHostingEnvironment env, IApiVersionDescriptionProvider provider)
{
    ...
    app.UseMvc();    
    app.UseSwagger();    app.UseSwaggerUI(c =>
    {
        c.ConfigureSwaggerVersions(provider);
    });
    ...
}

All being well you can now continue to use ASP NET Web API Versioning as per it's documentation. As a minimum your web API controller will want an ApiVersionAttribute and a RouteAttribute. Using the default ValueController that's created with a new Web API project it would look like this

[ApiVersion("1.0")]
[Route("api/v{api-version:apiVersion}/[controller]")]
public class ValuesController : Controller
{
    // GET api/values
    [HttpGet]
    public IEnumerable<string> Get()
    {
        return new string[] { "value1", "value2" };
    }
    ...

Configuring routes and templates

If you want to configure the titles on the Swagger description page you can pass a title template to ConfigureSwaggerVersions inside ConfigureServices in your Startup file.

public void ConfigureServices(IServiceCollection services)
{
    services.AddMvc();
    services.AddMvcCore().AddVersionedApiExplorer();
    services.AddApiVersioning();
    services.AddSwaggerGen(c => {
        var provider = services.BuildServiceProvider().GetRequiredService<IApiVersionDescriptionProvider>();
        c.ConfigureSwaggerVersions(provider, "Welcome to the documentation for version {0} of my API");
    });
    ...

Similarly, if you want to change the text in the version drop down you can using the SwaggerVersionOptions object. This lets you set the DescriptionTemplate for the version selector and RouteTemplate to alter the route.

//Note the change of method signature to include injection of IApiVersionDescriptionProvider
public void Configure(IApplicationBuilder app, IHostingEnvironment env, IApiVersionDescriptionProvider provider)
{
    ...
    app.UseMvc();
    app.UseSwagger();
    app.UseSwaggerUI(c =>
    {
        c.ConfigureSwaggerVersions(provider, new SwaggerVersionOptions
        {
            DescriptionTemplate = "Vesion {0} docs", RouteTemplate = "/swagger/{0}/swagger.json"
        });
    });
    ...
}

Note about MapToApiVersion

When using MapToApiVersion (example here) methods will be added for each ApiVersionAttribute specified on the controller. In the example this results in Get() and GetV3() being added to the 2.0 and 3.0 Swagger document. To avoid this, which will cause an overload error in Swashbuckle, you will need to add explicitly add the MapToApiVersion attribute to both methods rather than letting Get() default.

Referring again to the example it would look like this

[ApiVersion("2.0")]
[ApiVersion("3.0")]
[Route("api/v{version:apiVersion}/helloworld")]
public class HelloWorld2Controller : Controller
{
    [HttpGet, MapToApiVersion("2.0")]
    public string Get() => "Hello world v2!";

    [HttpGet, MapToApiVersion("3.0")]
    public string GetV3() => "Hello world v3!";
}

Using querystring versions

As of version 1.0.0-beta.1 and thanks to Microsoft.AspNetCore.Mvc.Versioning, querystring versioned APIs are now supported.

In a controller where no API version is specified a new parameter will be added to Swagger and will default to the API version you are browsing.

So this controller

[ApiVersion("1.0")]
[Route("api/[controller]")]
public class ValuesController : Controller
{
    // GET api/values
    [HttpGet]
    public IEnumerable<string> Get()
    {
        return new string[] { "value1", "value2" };
    }
}

will look like this

License

See the LICENSE file for license rights and limitations (MIT).