Response and Request Body Examples for NSwag

This library allows you to programmatically define swagger examples in your NSWag application. Example discovery occurs at start of application and uses reflection.

Install package

Install-Package NSwag.Examples

Setup Startup.cs

Add services needed for example definition using AddExampleProviders() and provide assemblies where are your examples located.

public void ConfigureServices(IServiceCollection services)
{
    services.AddControllers();

    services.AddExampleProviders(typeof(CityExample).Assembly);
    services.AddOpenApiDocument((settings, provider) =>
    {
        settings.AddExamples(provider);
    });
}

Define examples for your types

Create class and implement interface IExampleProvider where T is the type you want to define example for.

public class CityExample : IExampleProvider<City>
{
    public City GetExample()
    {
        return new City()
        {
            Id = 5,
            Name = "Brno",
            People = new List<Person>()
            {
                new Person() {Id = 1, FirstName = "Henry", LastName = "Cavill"},
                new Person() {Id = 2, FirstName = "John", LastName = "Doe"}
            }
        };
    }
}

Use dependency injection

You can also use dependency injection in constructor of your example provider class.

Constructor and GetExample method gets called when operation processors are executed - when swagger specification is being generated which is during first request on swagger.

public class PersonExample : IExampleProvider<Person>
{
    private readonly IPersonNameGenerator _nameGenerator;
    private readonly Random _random;

    public PersonExample(IPersonNameGenerator nameGenerator)
    {
        _nameGenerator = nameGenerator;
        _random = new Random(); 
    }

    public Person GetExample()
    {
        return new Person()
        {
            Id = _random.Next(1, 100),
            FirstName = _nameGenerator.GenerateRandomFirstName(),
            LastName = _nameGenerator.GenerateRandomLastName()
        };
    }
}

Request Body Parameters

For request body parameters there is nothing you need to worry about, just mark your parameter [FromBody].

[HttpPost]
public async Task<IActionResult> CreatePerson([FromBody, BindRequired] Person person)
{
    // create person logic
    return Ok();
}

Result in swagger:

Response Body

For response body types you need to decorate your method with [ProducesResponseType]

[HttpGet("{id}")]
[ProducesResponseType(StatusCodes.Status200OK, Type = typeof(Person))]
public async Task<IActionResult> GetPerson([FromRoute]int id)
{
    return Ok(new Person());
}

Result in swagger:

Support

I personally use this NuGet in my projects, so I will keep this repository up-to-date. Any ideas for extending functionalities are welcome, so create an issue with proposal.

Did I save you some hours?