F23.Hateoas

F23.Hateoas is a simple .NET library for working with HATEOAS (Hypermedia as the Engine of Application State) in ASP.NET Core applications. It provides a set of types that can be used to ensure consistent API responses containing optional hypermedia links.

Installation

You can install the library via NuGet Package Manager Console:

dotnet add package F23.Hateoas

or by adding a <PackageReference> to your project file.

Usage

Wrap all your API response objects with HypermediaResponse. This will allow you to add hypermedia links to the response if desired, but also acts as a consistent base response type for your API.

[HttpGet]
public IActionResult Get()
{
    var data = ... // Fetch your data

    return Ok(new HypermediaResponse(data)
    {
        Links = [
            new HypermediaLink("self", "/api/sample"),
            ...
        ]
    });
}

You might also find it helpful to create a helper method in a controller base class to simplify the creation of hypermedia responses:

public class MyBaseController : ControllerBase
{
    protected IActionResult HypermediaOk(object content, IList<HypermediaLink>? links = null)

    {
        return Ok(new HypermediaResponse(content) { Links = links });
    }
}

Then you can use it in your controllers like this:

[HttpGet]
public IActionResult Get()
{
    var data = ... // Fetch your data

    return HypermediaOk(data, [
        new HypermediaLink("self", "/api/sample"),
        ...
    ]);
}

Contributing

This package is very minimalistic and is not likely to need many updates. If you have a feature request or bug report, please file a GitHub issue. Once accepted by our team, you may submit a pull request. PRs without an accepted issue have a higher likelihood of being rejected.

Migrating from v1 to v2

Version 2.0.0 of this library introduced a breaking change by removing the Newtonsoft.Json dependency. If you need Newtonsoft.Json support, add a reference to the F23.Hateoas.NewtonsoftJson package and register the HypermediaResponseJsonConverter and HypermediaLinkJsonConverter with your JsonSerializerSettings.

For example, in ASP.NET Core startup:

using F23.Hateoas.NewtonsoftJson;

...

builder.Services.AddControllers()
    .AddNewtonsoftJson(options =>
    {
        options.SerializerSettings.Converters.Add(new HypermediaResponseJsonConverter());
        options.SerializerSettings.Converters.Add(new HypermediaLinkJsonConverter());
    });