RE: Comparing Activity Streams / Schema.org / Hydra (former: 'Fwd: Schema.org applies W3C Patent Policy')

+CC public-hydra

On 2 Sep 2014 at 16:42, James M Snell wrote:
> A review on these would be helpful.

Indeed... but what's even more important is to lay out the requirements and the use cases we are trying to address (I just joined the WG, so please forgive me if I'm not fully up to date yet).


> The model in AS2 is straightforward. For every object, there is an
> "actions" property whose value is a map of potential actions. This map
> takes the form of a JSON object mapping verb identifiers to so-called
> "action handlers". An action handler is a declarative description of
> how to carry out some kind of action.

Schema.org Actions and Hydra [1] are basically doing the same.


> Where schema.org/Actions, Hydra and the AS2 Action Handlers specs
> overlap is on the definition of those "action handlers". Where
> schema.org/Actions and AS2 conflict is on the use of the "actions"
> property in AS2 vs. "potentialAction" in schema.org.

By "conflict" you mean they use a different term (actions vs. potentialAction), right? Semantically they are equivalent AFAICT.
Hydra currently uses the term "operation" for this but we discussed to change it to "action" as well in the past [2].

In any case, Hydra follows a slightly different approach in that it describes the actions/operations supported by a web resource and not by an abstract thing. The model is

  {
    "@id": "http://example.com/my-resource",
    "@type": "Note",
    ...
    "operation": {
         "@type": "DeleteAction",    // multiple operations are supported
         "method": "DELETE"
    }
  }

whereas with AS this would look somewhat like this I think

  {
    "objectType": "note",
    ...
    "actions": {
      "delete": {
        "objectType": "HttpActionHandler",
        "url": " http://example.com/my-resource ",
        "method": "DELETE"
      }
    }
  }

The reason for this is that Hydra is primarily intended for RESTful Web APIs. You could of course use two separate resources as well, but then you'd need to "connect" them somehow.


> The approaches that schema.org/Actions and AS2 Actions take differ in
> a number of fairly obvious ways. Both, however, are capable of
> expressing the same basic information in relatively consistent ways.
> The devil, however, is always in the details.

Yep, the same is probably true about Hydra. As already said at the beginning of this mail, I think I first need to better understand what problems we are actually trying to solve. For example, is it a goal that machines invoke actions autonomously or is there always a human involved who presses a nicely rendered button?


Cheers,
Markus


[1] http://www.hydra-cg.com/spec/latest/core/
[2] https://github.com/HydraCG/Specifications/issues/2


--
Markus Lanthaler
@markuslanthaler



> 
> - James
> 
> On Tue, Sep 2, 2014 at 7:19 AM, ☮ elf Pavlik ☮
> <perpetual-tripper@wwelves.org> wrote:
>> Hello,
>> 
>> I would like to propose in depth discussion on Schema.org / Activity
>> Streams / Hydra
>> 
>> We have both ActivityStreams & Schema.org listed at
>> https://www.w3.org/wiki/Socialwg/Social_syntax
>> 
>> I can also recall at least two articles by James Snell where he works
>> with them both:
>> *
>> http://www.chmod777self.com/2014/04/activity-streams-20-and-schemaorgactions.html
>> * http://www.chmod777self.com/2014/05/more-on-activity-streams-20-and.html
>> 
>> Then again Schema.org Actions and Hydra have many similarities and
>> history of collaboration:
>> http://blog.schema.org/2014/04/announcing-schemaorg-actions.html
>> 
>> I must admit not reading enough yet about Activity Streams 2.0 Action
>> Handlers to position them here...
>> 
>> #ACTION - Would someone like to work with me in next two weeks to
>> prepare overview of similarities and differences in all mentioned
>> technologies? It would hopefully make it much easier for everyone to
>> engage in further conversation.
>> 
>> Cheers!
>> 
>> On 09/01/2014 07:58 PM, Harry Halpin wrote:
>>> In case people missed this from the last IG meeting!
>>> 
>>> -------- Forwarded Message --------
>>> Subject: Schema.org applies W3C Patent Policy
>>> Resent-Date: Mon, 01 Sep 2014 17:54:15 +0000
>>> Resent-From: public-socialweb@w3.org
>>> Date: Mon, 01 Sep 2014 19:54:07 +0200
>>> From: Harry Halpin <hhalpin@w3.org>
>>> To: public-socialweb@w3.org <public-socialweb@w3.org>
>>> 
>>> Those who were at the Social Standards workshop last August will
>>> remember a discussion with Guha over schema.org and licensing. People
>>> should  know that Schema.org has now changed their licensing to be
>>> royalty-free in the following manner:
>>> 
>>> "The Sponsors have applied the W3C Patent Policy to the schemas
>>> published by Schema.org as follows: each Sponsor, by itself and on
>>> behalf of its affiliates, agrees to make available under W3C RF
>>> licensing requirements its Essential Claims (if any) in the schemas
>>> published by Schema.org as if the schemas were W3C Recommendations. In
>>> some cases, this website may indicate that some but not all of the
>>> Sponsors have recognized a particular extension to the Schema; in
>>> those cases, as to that extension, the above rights are granted by
>>> only those recognizing Sponsors. " [1]
>>> 
>>>    cheers,
>>>     harry
>>> [1]https://www.schema.org/docs/terms.html
>>> 
>> 
>>

Received on Wednesday, 3 September 2014 21:15:24 UTC