Hydra W3C Community Group Telecon

Minutes for 2017-10-02

  1. ISSUE-134: Adding already existing resources as collection members
  2. Heracles PR-10 (Action item Markus to combine PR-10 & PR-12)
  1. Merge Heracles PR-10
Markus Lanthaler
Karol Szczepański
Markus Lanthaler, elf Pavlik, Tomasz Pluskiewicz, Karol Szczepański
Audio Log
Markus Lanthaler: Meeting: Hydra W3C Community Group Conference Call
elf Pavlik: present+
Karol Szczepański is scribing.

Topic: ISSUE-134: Adding already existing resources as collection members

Agenda: Issue #134
Markus Lanthaler: The action items were
Markus Lanthaler: 1) Karol to analyse Jiira/Confluence APIs
Markus Lanthaler: 2) Pavlik to analyse meetup.com and look for another one
Markus Lanthaler: 3) Markus to analyze some Google APIs
Markus Lanthaler: 4) Tomasz to analyze Huddle & Foxycart
Karol Szczepański: Confluence's APIs is consistent within itself and uses collections as containers, i.e., you can POST entities to a collection [scribe assist by Markus Lanthaler]
Karol Szczepański: Jiira's API isn't consistent and uses different mechanisms [scribe assist by Markus Lanthaler]
Karol Szczepański: when I say a container I mean a LDP container [scribe assist by Markus Lanthaler]
Karol Szczepański: so when adding a resource, it will get it's own URL [scribe assist by Markus Lanthaler]
Karol Szczepański: and the container itself has a URL as well and can be updated with a PUT e.g. [scribe assist by Markus Lanthaler]
Markus Lanthaler: So, with a playlist, e.g., video entries would be represented as separate playlistitem resources, right
Karol Szczepański: yes [scribe assist by Markus Lanthaler]
Markus Lanthaler: Did you see any use HTTP LINK or UNLINK?
Karol Szczepański: no, I haven't [scribe assist by Markus Lanthaler]
elf Pavlik: I posted my findings on GitHub
... Veimo case: like relationship or subscription relationship
... requires understanding URI patterns
... URI patterns are not provided, thus client needs to have that knowledge
elf Pavlik: putting or deleting a relationship ammends both collections
elf Pavlik: in vimeo puts or deletis single resources rather than PATCH a collection
Tomasz Pluskiewicz: nothings can stop server from modifying other collections/resources
Markus Lanthaler: if the client wan'ts to update both collections, does it needs to know whether to do it manualty or it can know that server will do that
Tomasz Pluskiewicz: it would be ackward to take care of all possible side effects or lack of those
Markus Lanthaler: client probably is not aware of the all resources it is going to affect
Markus Lanthaler: expressing side effects opens brand new can of worms
elf Pavlik: modifying dataset or interacting with an interface are two possible approaches
Karol Szczepański: I think it is not up to Hydra to decide [scribe assist by Markus Lanthaler]
... the client should get told what it can do and not care whether it interacts with a dataset or service
... it will be a service in either case
... and we shouldn't leak the underlying implementation
elf Pavlik: difference is on how to provide the information of the posible operation i.e. to like something
elf Pavlik: either with a Like action or something different
Karol Szczepański: adding semantic actions such as LikeActions should be optional and be on top of PUT, POST etc. [scribe assist by Markus Lanthaler]
... the client may not understand those higher level actions LikeActions
Markus Lanthaler: So, what is a POST?
Markus Lanthaler: If the server only advertises a POST, how would the client know what it effects are?
Karol Szczepański: It wouldn't and it shouldn't execute it.. only GET is a safe operation [scribe assist by Markus Lanthaler]
I've lost you guys
Karol Szczepański: i worry that if we take actions from schema.org Like etc. we may end up with somethign SOAPish [scribe assist by elf Pavlik]
Tomasz Pluskiewicz: I don't see issue with the verbs itself, but we don't get RPC because of that [scribe assist by elf Pavlik]
Tomasz Pluskiewicz: RPC tries to pretend that remote calls are local calls [scribe assist by elf Pavlik]
Karol Szczepański: the clients know the protocol, the common verbs, errors etc. now you would need to understand more, like those verbs from the vocab [scribe assist by elf Pavlik]
sorry, my connection dropped
back now
Tomasz Pluskiewicz: you always need some kind of vocab besides minimal HTTP semantics [scribe assist by elf Pavlik]
elf Pavlik: do we wan't to support different choices i.e. one server uses PUT and another to POST or PATH or other verb for same operation
Karol Szczepański: IMO user of the API doesn't need to know a vocabulary to perform some actions [scribe assist by elf Pavlik]
Markus Lanthaler: if there is a developer that implements an HTTP requests as document the server cannot change that implementation
Markus Lanthaler: other approach is that client can be written so server can change that behavior
elf Pavlik: various services might need to make some choices on the custom actions
elf Pavlik: having notion of an action is more extensible
elf Pavlik: I like the idea of trying to describe the APIs we researched with Hydra [scribe assist by Markus Lanthaler]
Karol Szczepański: I like the idea of implementing something [scribe assist by Markus Lanthaler]
Markus Lanthaler: I agree
Markus Lanthaler: So, should we continue with implementing the use cases, add new use cases if some are missing etc.
Markus Lanthaler: Or would you like to investigate something else
Karol Szczepański: Let's continue to implement the existing use cases [scribe assist by Markus Lanthaler]
... we can always extend them if necessarz
elf Pavlik: shall we try to add something to the heracles from the use cases?
Karol Szczepański: yes, absolutely [scribe assist by Markus Lanthaler]
... you should contribute, it's our code not mine

Topic: Heracles PR-10 (Action item Markus to combine PR-10 & PR-12)

Tomasz Pluskiewicz: go ahead, we can always tweak details
PROPOSAL: Merge Heracles PR-10
Markus Lanthaler: +1
Markus Lanthaler: arrange order of the members so public static goes first, the public, protected and private
elf Pavlik: +1
Karol Szczepański: +1
Tomasz Pluskiewicz: +1
RESOLUTION: Merge Heracles PR-10
elf Pavlik: pick an issues and let's implement in the heracles
Karol Szczepański: we have the use cases, just pick one, implement it and send a PR [scribe assist by Markus Lanthaler]