Pure HTML vs frameworks to define HATEOAS API?

Question

When should one develop HATEOAS server RESTful API instead of using HTML (resource links, forms, etc.)?

Isn't HTML and a browser good enough as hypermedia engine?

Answer 1

Isn't HTML and a browser good enough as hypermedia engine?

HTML + HTTP + URI + Browser === The world wide web. So it's pretty good, no joke.

It's not without fault.

HTML's understanding of links is disappointingly limited. No support for idempotent writes. Uri Template support for GET only. I'm not super keen on how many different spellings there are for "link".

It's kind of verbose for a hypermedia format; don't get me wrong - built in text markup is brilliant when you are trying to document what is going on for a human being. But my impression thus far is that same structure starts to get in the way when as a human being you want to quickly review the semantic content that your automated agent is consuming.

I call your attention to this quote from RFC-4287

The primary use case that Atom addresses is the syndication of Web content such as weblogs and news headlines to Web sites as well as directly to user agents.

So a bunch of really smart guys, specifically trying to address use cases directly related to the web, decided to invest a bunch of effort into standardizing a new hypermedia format rather than using the one that was already ubiquitous in their problem domain.

And over the past 10+ years, that format has been widely adopted.

Without adoption, I'm not sure that HATEOAS has much benefit. You don't need a hypermedia api if you are controlling both sides of the conversation (example: javascript on the web -- hypermedia with code on demand capability downloading a client that has learned the protocol of a web api via some out of band channel).

Evidence would seem to suggest that HTML is not nearly as convenient a format as, for example, any of the JSON based hypermedia formats.

In conclusion: no, it's not good enough. It might be an acceptable place holder for the moment; but the JSON hypermedia tool sets are soon going to be sufficiently mature that HTML will be seen as a giant step in the wrong direction.