Add hydra:collection to resources

[tpluscode]

As surfaced but HydraCG/api-examples#4, Alcaeus needs to natively support hydra:collection property.

I can think of two ways to add it to the API.

First would be to implicitly treat hydra:collection as a hydra:Link property. I would add a getLinks() method to the base resource type so which gathers explicit links and collections in a single array.

const response = await Hydra.loadResource(url)
const resource = response.root

// will return collections and links defined as `hydra:Link`
resource.getLinks()

I favour this approach as it will play nice with the generic app and is one less place too look at when processing Hydra representations.

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Alternatively, a dedicated property/method could be introduced which only accesses the related collections.

I do feel though that it's just bloat.

[tpluscode]

@angelo-v what do you think?

[angelo-v]

I did not use Alceaus yet, so I am not sure which fits better in the "thinking" of it. In general I think collections are a core element of each API and it does not feel like bloat to me. In contrast, I would like to have more specific ways to find collections in an API, e.g. to say something like getCollections(Movie) to find collections that manage specific types.

[tpluscode]

In general I think collections are a core element of each API and it does not feel like bloat to me

Thanks for sharing your thoughts.

I actually came to this conclusion through different reasoning. If you remember, I mentioned to you and Karol that in a PoC I used collection property to describe supported properties. Thus, it cannot be reduced to links only but has to be its own piece of the library API.

to find collections that manage specific types.

Interesting idea. Such snippets have floated around the spec repository although I'm not sure what is the practical application yet. Also, the manages information can be found in more than one place I think.