Hydra W3C Community Group Telecon

Minutes for 2018-04-02

elf Pavlik is scribing.
Markus Lanthaler: we don't have an agenda, what would you like to discuss?
Karol Szczepański: I don't know the state of the 154 (actions) PR

Topic: Actions with explicit target (#154)

elf Pavlik: I made a very small commit based on what we discussed previously [scribe assist by Markus Lanthaler]
... as I pointed out before, use cases 5 and 5.1 has more differences than necessarz
... this PR makes both use a UUID
... once the server creates the UUID, once the client
... both of them use the same pseudo-code now
... (like the one Markus posted on GitHub)
Karol Szczepański: I implemented that feature for Herakles.ts, it has component for filing up iri template
Karol Szczepański: I see issue with specification not explaining how to get values for variables in a template based on properties in the mapping
my approach takes 2 resources, first goes into payload and second gets used for values in IRI template variables
Markus Lanthaler: at some point we need to define how IRI templates relate to request
... have you thought more about that give your implementation xp in heracls?
Karol Szczepański: in case where you have iri template and the payload, the template can have variables which values will not come from the payload
elf Pavlik: I think we miss some use cases [scribe assist by Markus Lanthaler]
Markus Lanthaler: ... so far we have only two: one using UUID, one using slugs
... maybe we should create a few more use cases
... the UUID, e.g., appears only in the URL but not in the payload
... Linked Data Fragments use subject, predicate and object in their URL templates
... it uses them as kind of reified statements.. not properties of the resources
Markus Lanthaler: yeah, that's a good point [scribe assist by Markus Lanthaler]
Karol Szczepański: we may miss something in the spec explaining how to 'craft' the whole request
... we have details on how to 'craft' body
... but not enough clarity on IRI templates, or request headers
... HTTP request can have headers but spec doesn't account for that
Markus Lanthaler: i thought that we should make 'expect' some data shape which would instruct what goes in the payload etc.
Karol Szczepański: I recall Tomasz suggesting something in this direction
Markus Lanthaler: we could for example use SHACL
ACTION: Markus to write down a proposal on how a expects "request shape" could look like
Sorry, but no Tracker is associated with this channel.
elf Pavlik: maybe we could build around UC5 and UC5.1 in two versions 1 - could use UUID like in my last commit to PR 154 and the other one could use *slug* for both 5 & 5.1 as attempted in previous version of UC5.1
elf Pavlik: I would like to see more use cases that require actions with an explicit target [scribe assist by Markus Lanthaler]
... currently it seems most of them could be handled with memberTemplate
Markus Lanthaler: something related to IRI templates in issue about 'filtering enumerations'
Karol Szczepański: I have question related to PR on Herakles.ts

Topic: Usage of Hydra vocabulary in Heracles.ts

... you suggested something about using official Hydra JSON-LD context
Markus Lanthaler: namespace IRI responds with JSON-LD context
Karol Szczepański: Markus, we can't hear you
Karol Szczepański: I will embed this context statically for now and make issue to load it dynamically
Markus Lanthaler: In general it takes a while go get through those PRs, do you have suggestions on how to improve it
Karol Szczepański: I'll try to continue with having multiple PRs open at the same time and let them land as it progresses

Topic: Usage of actions in ApiDocumentation

Markus Lanthaler: for ApiDocumentation one would need to create dedicated property for that
Karol Szczepański: we could try to make ApiDocumentation for existing use cases
elf Pavlik: we should also decide whether ApiDocumentation is supposed to support everything that can be done inline [scribe assist by Markus Lanthaler]
Markus Lanthaler: I would find it nice if they both have the same scope but we may not find it possible
Karol Szczepański: let's try with our existing use cases first and see how it looks
ACTION: Karol, to extend use cases to include ApiDocumentation examples
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Topic: Subject URL in POSTs

elf Pavlik: when POSTing something, the client doesn't provide a URL (@id in JSON-LD) [scribe assist by Markus Lanthaler]
... is the server supposed to return the subject URL in the response
Karol Szczepański: POST should provide IRI in Location header
... quote from RFC
Karol Szczepański: we discussed possibility of including `@id` or not based if you create or update
Markus Lanthaler: if you send POST with multiple addresses server could split it into multiple resources
ACTION: Pavlik, to create issue regarding subject in POSTs etc.