good use case of HATEOAS

Question

may I have some example/typical use case of HATEOAS? I agree it can be a very powerful concept provide great flexibility but I am not sure how to properly get benefit from HATEOAS. would be great if you can share your experience/use case.

Answer 1

A good answer from @dreamer above, but HATEOAS is not present in most REST-based services. It is a constraint on the REST architecture style that allows clients to interact with a service entirely via the hypermedia contained in the resources.

If you look at the Twitter or Facebook REST APIs, you won't find hypermedia. Look at the Facebook friendlist resource. There are no hypertext links in that resource that you can use to transition the state of the resource - to delete, update, etc. Instead, you need to read the out-of-band documentation to understand what you need to do to delete that resource.

One of the claimed advantages of using hypermedia in your APIs is that you can manage change within the resources themselves. For example, what if Facebook wanted to add additional functionality to the frendlist? If it were built with HATEOAS in mind, the resource would be updated to add the hyperlinks provides those additional state transitions.

If this sounds difficult, you're right. But as a developer of client applications, however, once you understand how the hypermedia is presented, you can build applications that will evolve along with the API itself.

So how do you build APIs using HATEOAS? A number of options are out there, but I like the Hypertext Application Language (HAL) the best.

UPDATE: Since you asked for an example, here's a link to a demo using HAL.

Answer 2

Good public HATEOAS use cases are hard to find, because there are a lot of misconceptions around REST, and HATEOAS can be hard to implement. You really need to have a good understanding of its benefits, before you're willing to put yourself through the trouble of getting it to work, and if the clients don't follow it correctly, all work will be in vain.

From my experience, implementing proper REST in a company is a culture change as important as moving to version control systems or agile development. Unless everyone adopts it and understands it, it causes more trouble than it solves.

Having that in mind, I think the best example one will find is the foxycart.com HAL API, on the link below:

https://api-sandbox.foxycart.com/hal-browser/hal_browser.html#/