SierraLib.API.Views

A pattern for versioned views into your data model for APIs

This library provides a pair of interfaces and some extension methods which act as a framework on which you can build and maintain multiple, versioned, views into your core data models. It has been designed to work in concert with good API design patterns like versioned endpoints and semantic versioning to simplify the development of backwards compatible API surfaces as your services evolve.

Example

namespace Example
{
    using SierraLib.API.Views;

    public class UserProfile
    {
        public Guid Id { get; set; }

        public string Fullname { get; set; }

        public DateTime DateOfBirth { get; set; }

        public class Version1 : IView<UserProfile>
        {
            public string Id { get; set; }

            public string Fullname { get; set; }

            public DateTime DateOfBirth { get; set; }

            public class Representer : IRepresenter<UserProfile, Version1>
            {
                public UserProfile ToModel(Version1 view)
                {
                    return new UserProfile
                    {
                        Id = view.Id is null ? Guid.NewGuid() : Guid.ParseExact(view.Id, "N"),
                        Fullname = view.Fullname,
                        DateOfBirth = view.DateOfBirth,
                    };
                }

                public Version1 ToView(UserProfile model)
                {
                    return new Version1
                    {
                        Id = model.Id.ToString("N"),
                        Fullname = model.Fullname,
                        DateOfBirth = model.DateOfBirth,
                    };
                }
            }
        }
    }
}

Interfaces

IView<TModel>

The IView interface is used to mark classes which represent a view into a specific model.

IRepresenter<TModel, TView>

The IRepresenter interface provides the ToModel and ToView methods and is responsible for working to convert between the TModel and the TView.