Application of HATEOAS Principle in RESTful API Design

Hypermedia as the Engine of Application State (HATEOAS) is a principle that has been built upon the term hypermedia to refer to a constraint on the Representational State Transfer (REST) application architecture. This principle distinguishes REST from other application architectures, such as Simple Object Access Protocol in a way that client applications (e.g., a web app or a mobile app) need no prior knowledge for interacting with a REST-based Application Programming Interface (API) beyond a generic understanding of its hypermedia. Ion is an intuitive JavaScript Object Notation-based hypermedia type for REST, which can help software developers realize the principle of HATEOAS in their API design with ease. The goal of the work that is described in this paper has been to practically demonstrate the use of Ion in practice to have a self-documented REST API. For this purpose, a C# library has been implemented to demonstrate the use of Ion in having a REST API with self-documentation.