Re: Hypermedia and media types

If you are talking about dumb transformation of serialization formats
like JSON-LD to RDF/XML etc. then you are certainly right.
But even supporting JSON-LD (+Hydra) and plain JSON is a whole different 
story.
There is so much more you need to consider and implement in your API
server for JSON-LD compared to JSON.
Not to mention the challanges if you have to drive a "procedural model"
(operations in the case of hydra). There is simply not
a 1:1 relation of concepts in hydra, HAL, siren, JSON API etc.


On 08/18/2015 10:51 PM, mike amundsen wrote:
> <snip>
> if you are in a typical project setting hardly possible because you 
> will get killed by the effort.
> </snip>
>
> you don't need to "kill yourself" adding support for message models.
>
> using a typical Strategy pattern[1] and a canonical resource object 
> model, I am able to add support for a new media type in <300 lines of 
> NodeJS. that means I can build up a new representor (discussion at 
> [2]) in a single day and debug/tweak it in another day or so. that's 
> around 20 work hours between selection and production.
>
> hope this helps.
>
>
> [1] http://www.oodesign.com/strategy-pattern.html
> [2] 
> https://groups.google.com/forum/#!msg/hypermedia-web/FXy1Mcuhj_0/W3aehrijwh0J 
> <https://groups.google.com/forum/#%21msg/hypermedia-web/FXy1Mcuhj_0/W3aehrijwh0J>
>
>
> mamund
> +1.859.757.1449
> skype: mca.amundsen
> http://amundsen.com/blog/
> http://twitter.com/mamund
> https://github.com/mamund
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>
> On Tue, Aug 18, 2015 at 4:21 PM, Thomas Hoppe <thomas.hoppe@n-fuse.de 
> <mailto:thomas.hoppe@n-fuse.de>> wrote:
>
>     Hi Dimitri,
>
>     just my 50 cents on two aspects from your mail.
>
>     "In my opinion, methods, operations and validations has got
>     nothing to do with the data itself"
>
>     That's of course true and that's why you would not store them in
>     your persistence layer.
>     We enrich the resources read from the database (there is no nee to
>     employ a triple store btw.)
>     with the operations dynamically when they are delivered to solve this.
>
>     "I'm about to start supporting them all and let the client choose
>     which one to use"
>
>     Building APIs with hydra and JSON-LD for 3 years now and knowing
>     those others
>     that are around [1] I can tell you that this is noble goal but if
>     you are in a typical
>     project setting hardly possible because you will get killed by the
>     effort.
>
>     Greets, Thomas
>
>     [1]
>     http://vanthome.github.io/rest-api-essay-presentation/rest_apis.html
>
>
>     On 08/18/2015 05:31 PM, Dimitri van Hees wrote:
>
>         Hi all,
>
>         I'm designing an API and I am struggling with the choice of
>         supported hypermedia standards. Fact: we need to paginate
>         through collections of data. I'd like to offer both plain JSON
>         and JSON-LD and let the client choose which response he wants
>         using the accept header. This is no problem because we can
>         simply use application/json and application/ld+json.
>
>         Problems arise when we also want to add hypermedia to the
>         response. In my opinion, one of the hypermedia versions of my
>         the JSON response is HAL, returned when application/hal+json
>         is being requested. The hypermedia version of the JSON-LD
>         response should be Hydra, but as far as I know Hydra doesn't
>         have it's own media type because it's in fact just valid
>         application/ld+json. However, JSON-LD is also in fact just
>         valid application/json, yet still has it's own media type.
>         Just like HAL by the way, which is also just valid
>         application/json.
>
>         I think that one of the nicest things of JSON-LD is that it
>         can be converted to RDF and that the URL actually is the
>         object itself. So I want to give people the choice between
>         fetching just the resource in JSON-LD *and* fetching the
>         resource with hypermedia (Hydra in this case). In my opinion,
>         methods, operations and validations has got nothing to do with
>         the data itself, so I can imagine use cases where I don't want
>         that data in a triplestore for example. As Hydra doesn't have
>         it's own media type, what would be the best practice to
>         achieve this?
>
>         The same counts for the non LD responses by the way. There 
>         are so many hypermedia standards out there that I can't choose
>         which one to use. In fact I think I'm about to start
>         supporting them all and let the client choose which one to
>         use. But then again, there should also be a possibility to
>         fetch just the plain old JSON object, without any hypermedia.
>         Then again, most people always return hypermedia (say
>         application/hal+json), even when the accept header is
>         application/json. Perhaps there should be something like
>         application/raw+json... ;-)
>
>         Any thoughts on this?
>
>         Regards,
>
>         Dimitri van Hees
>
>
>
>