Re: Link relation types for non-GET links

[Erik Wilde <[e-mail]>]

hello klaus.

On 2015-08-15 13:56, Klaus Hartke wrote:
> Mike Amundsen wrote:
>> I think an important design decision is whether you want to overload a link
>> rel value ("edit", "item", "collection", "payment") with protocol-level
>> information like "idempotent", "safe", etc. or rendering information like
>> "transclude", "immutable:, etc. My advice is to keep them separate.
> That's exactly what my initial question was about: should all
> hypermedia controls take the shape of a link, with the link relation
> types providing all the necessary details (like request method,
> presentation, etc.), or should a media type provide a number of
> syntactically different hypermedia controls so that the relation type
> really only indicates the semantic meaning of the control.

you can go both ways, and different people have different opinions. my 
meta-opinion is that there is no "right way" of doing it, and my 
meta-guidance is to at least always be consistent in the set of services 
or media types you're designing.

my non-meta-opinion is like mike's: keep the link relations general and 
generic, just specific enough so that hypermedia controls can be 
identified in representations. then design the representation to provide 
all the details that your scenario might need. here's my reasoning:

- this way you keep the existing/registered link relations to a minimum, 
by not assuming that every little piece of information is implied in the 
link relation type. instead, that's the job of the link's context and 
can be adjusted as needed.

- this way you also can make certain mechanisms (such as the link 
descriptions i am working on) reusable, so that they can be used for 
*any* kind of link relation type where you might want to use them.

to me, this is a question of separation of concerns, but i have had long 
discussions with that with people leaning the opposite direction.

like i said, the most important thing: pick a style and be consistent.

cheers,

dret.

-- 
erik wilde | mailto:[e-mail]  -  tel:[phone] |
            | UC Berkeley  -  School of Information (ISchool) |
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