Hypermedia as the Engine of Application State (HATEOAS)

Re:Hypermedia as the Engine of Application State (HATEOAS) by ivan_gammel on Tuesday August 01, 2023 @07:05PM (#36964505)

I don’t think that is a good explanation.

> REST is about describing services that you can interact with with no prior knowledge. REST is about completely decoupling the client and server (in terms of prior knowledge) beyond standardized media types (HTML, CSS, JS)

The idea that REST is confined to standard media types like HTML and CSS is wrong. It is sufficient that media types are known to specific clients and server, but that does not have to include web browsers or arbitrary clients.

Quote [1]:

REST provides a hybrid of all three options by focusing on a shared understanding of data types with metadata, but limiting the scope of what is revealed to a standardized interface. REST components communicate by transferring a representation of a resource in a format matching one of an evolving set of standard data types, selected dynamically based on the capabilities or desires of the recipient and the nature of the resource. Whether the representation is in the same format as the raw source, or is derived from the source, remains hidden behind the interface. The benefits of the mobile object style are approximated by sending a representation that consists of instructions in the standard data format of an encapsulated rendering engine (e.g., Java [45]).

[1] https://www.ics.uci.edu/~fielding/pubs/dissertation/rest_arc...

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Re:Hypermedia as the Engine of Application State (HATEOAS) by cxr on Tuesday August 01, 2023 @08:21PM (#36965215)

I don't get what your quibble is.

> The idea that REST is confined to standard media types[...] is wrong

You sourced the response yourself:

> REST components communicate by transferring a representation of a resource in a format matching one of an evolving set of standard data types

... and given that you did just copy and paste that part, it leads me to believe that that's not what you've got an issue with. So what do you have an issue with?

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Re:Hypermedia as the Engine of Application State (HATEOAS) by ivan_gammel on Wednesday August 02, 2023 @05:50AM (#36968858)

„Standard media type” has different meaning in the comment you refer to and in the quote.

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Re:Hypermedia as the Engine of Application State (HATEOAS) by cxr on Wednesday August 02, 2023 @06:14AM (#36968973)

This is not a very helpful response.

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Re:Hypermedia as the Engine of Application State (HATEOAS) by ivan_gammel on Wednesday August 02, 2023 @09:25AM (#36970572)

You reference a comment that basically says that REST is HTML UI talking to server via links and forms, rather than interaction with JSON or XML-based API. This is not correct, neither according to original dissertation nor according to modern understanding of RMM 3 APIs. API using JSON can support HATEOAS. Standard media type in the sense of REST is not the W3C media type, but anything that both server and client can understand. appilcation/hal+json is a good example.

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Re:Hypermedia as the Engine of Application State (HATEOAS) by cxr on Wednesday August 02, 2023 @12:18PM (#36972971)

Nope. Try again. It "basically" says what it says—which is the same thing that the part you quoted from Fielding says—and nowhere does it say that the media type has to be HTML, which is what you (now) seem to be implying (but are unable or unwilling to articulate for some reason).

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Re:Hypermedia as the Engine of Application State (HATEOAS) by ivan_gammel on Wednesday August 02, 2023 @04:44PM (#36977128)

How exactly do you understand the following quote that is part of what you call a „good explanation“?

> REST is about completely decoupling the client and server (in terms of prior knowledge) beyond standardized media types (HTML, CSS, JS)

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Re:Hypermedia as the Engine of Application State (HATEOAS) by cxr on Wednesday August 02, 2023 @11:24PM (#36980974)

I understand it the way it's written. I don't know what you're looking for here; jcrites is not staying that { HTML, CSS, JS } are prerequisites to REST. They're giving examples of standard media types. If there are other media types for which it is possible to do REST, then those are acceptable, too, of course. But HTML is not a requirement.

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Re:Hypermedia as the Engine of Application State (HATEOAS) by whstl on Sunday August 06, 2023 @08:05AM (#37021095)

The comment you're complaining about says "beyond standardized media types (HTML, CSS, JS)".

"Beyond" in this case means "not only".

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Re:Hypermedia as the Engine of Application State (HATEOAS) by myk9001 on Wednesday August 02, 2023 @05:10AM (#36968671)

You're absolutely correct in stating REST is not confined to HTML, CSS, JS. A JSON, XML, or binary-based media type are all compatible with the architectural style.

I don't think the grandparent implies otherwise, though. They are using the browser/HTML example to describe the particular mechanics of client/server interaction, which are key to a REST application.

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