See also: IRC log
<FabGandon> scribe:cygri
UNKNOWN_SPEAKER: The feeds come
from a variety of content providers.
... Properties (keys, etc.) used in the feed are not the same
across services
... To keep apps simple, I need things to be represented the
same way no matter where they come from
cygri: present+ Richard Cyganiak
tidoust: So as an app developer,
we wrap the difference between services away in an internal
API
... normalising the different feeds
<oberger> did he mention semantics ?
tidoust: I assume that most web
app developers are facing similar situations
... So it would be good if content providers did things the
same way
... Linked data is the response to this problem.
<develD> +1
<develD> (to cygry)
tidoust: I see two promising
initiatives
... 1. Linked data platform WG
<develD> i'm interested in to put rdf into a feed
tidoust: 2. JSON-LD
<oberger> JSON-LDP :-)
tidoust: JSON-LD started as community group, then taken up by RDF-WG
<develD> i'm interested in to use pubsubhubbub with web access control
tidoust: JSON-LD allows using JSON as usual, with a little bit of magic (a context) and resolve issues of different representation
betehess: Alexandre Bertails, W3C
Systems team
... I had exactly the same issue when starting to work on a new
platform at W3C
... had to deal with lots of streams of data, different things
talking to each other
... Build lots of APIs, web services?
... Decided to just use RDF
... But at this time there was no clear way of doing this
... At this time, IBM made a submission to W3C, describing one
way of handling data
... Statements, HTTP URIs
<oberger> LDP is not ready yet
betehess: JSON is great because
works in the browser easily
... Define in one place your terms
... As a developer I still see problems
... SPARQL is great, but with LDP ...
[scribe didn't catch the point, betehess may want to add it here]
Alexandre Morgeaut: (sp?) JSON-LD vs. JSON Schema?
<betehess> my main point: LDP is great but something is missing to speak about some usual datastructures that one would want to encode in RDF
tidoust: JSON Schema is an IETF
draft that does for JSON what XML Schema does for XML
... JSON Schema is fairly simple because JSON is simpler than
XML
... In JSON-LD you add a “context”; in JSON Schema you define a
schema; right now there's no bridge
timbl: JSON Schema or XML Schema are in the document structure worl
<SteveS> @betehess what data structures are you referring? saying there should be something to help describe the shape of resources
timbl: it's not in the linked
data world
... RDF Schema shouldn't be called Schema by the way as it
doesn't talk about document structure but structures in the
real world
... RDF people haven't addressed doc structure
... There is no RDF graph constraint language
<betehess> SteveS: on the top of my head, I need: set, ordered list, indexed list, map, tuple, options, either (this denotes alternatives)
timbl: Nothing that allows you to say: “If you stick a value in here, then you can submit it there”
<yvesr> well, you could argue SPARQL is one?
timbl: That would be interesting and would allow doing evaluation
ivan: (Ivan Herman, W3C Semantic
Web Activity Lead)
... We consider data validation
... We are seriously considering a workshop around that issue.
No commitment!
cygri: Yes, we want that
SteveS: Steve Speicher, IBM
... We created this vocabulary that describes the shape of a
resource description
... based on SPARQL ASK
Arnaud: ArnaudLH Le Hors, IBM,
LDP WG Chair
... XML selling point was that it doesn't constrain the data
model
<yvesr> +1 on SPARQL ASK for validation purposes
Arnaud: But not really true, we
ended up defining a data model to program against
... that's the XML Infoset
... RDF starts with the data model and then a bunch of
syntaxes
... JSON-LD gives a JSON-friendly way of interacting with
RDF
<oberger> what about Turtle and web developers ?
Arnaud: So very different from JSON Schema
<oberger> betehess, are we supposed to use the queue ?
Alexandre: In JSON Schema you can
talk about types of properties (?)
... E.g, saying something is a URL
<SteveS> Some early work on a validation/constraint model for RDF data models http://open-services.net/bin/view/Main/OSLCCoreSpecAppendixA#oslc_ResourceShape_Resource … be interested to what we can do at W3C
tidoust: There are similar things in JSON-LD, you can say that a certain key's vlaue is not taken as string but as IRI
oberger: Olivier Berger
... Are we discussing publishing or consuming
information?
... Consuming is more difficult
... Especially with different sources. Spam, untrusted
information
... Can we show an approach to handling trust of the data you
want to consume, based on linked data?
tidoust: Even with content provider that provide a feed, you may have to reject some content because it's garbage
timbl: In linked data, you can
start with a certain person, then look at that person's
friends' friends'
... following through the graph, using only data according to
that graph
... web of trust
... following a trail of trust through the graph. very natural
in the LD world
Ruben: Ruben Verbough
... Many applications combine styles. Bit of consumption, bit
of production
... What's a solution that facilitates this?
... No semantics in JSON, so you only do what you need to
do
<betehess> Ruben: today we have no semantics in JSON, you just do what you have to do
Ruben: Use cases?
tidoust: LDP is read-write
ruben: What people do today is just change a bit of JSON around
tidoust: Goal is to make life of developers easier
betehess: rdflib.js
... There are RDF libraries
... Let's say I'm a developer who wants to work with RDF as an
RDF graph; not as SPARQL result or tree
... Finding a particular node in the graph and follow some
links
<yvesr> reminds me of http://www.w3.org/TR/2011/WD-rdf-interfaces-20110510/ - rdf api for javascript
betehess: I want to have an LDP
API that just does it for me, just follows some nodes
... and does the LDP GET requests etc
... I'd like timbl to speak about rdflib
<oberger> what about PHP ?
betehess: on tension between using pure javascript with JSON, or something like rdflib
<Ruben> +1 on jQuery for RDF
timbl: We need jQuery for RDF.
What's neat about jQuery is that you need very few
keystrokes
... not always understandable, but the program shrinks
... it abuses JS as much as it can to make things shorter
<oberger> betehess, any URL for rdflib.js ?
timbl: one should be able to do simliar things with RDF
<betehess> oberger: https://github.com/linkeddata/rdflib.js/
timbl: So the thing you create is
a quad store
... kb.sym("some URI")
<yvesr> Ruben, not sure what the status of rdfQuery is? https://github.com/alohaeditor/rdfQuery
timbl: and that returns an internal representation of that thing
<betehess> the way I understand timbl's KB, it's a way to speak about trust (you add in your KB what the facts you want to considerer)
timbl: kb.any(x, dc:title) will return the object
<JeniT> yvesr: I haven't worked on it for a long time
timbl: kb.the(x, dc:title) will return only one; runtime error if multiple
<JeniT> yvesr: rdflib.js incorporates some of the code
timbl: kb.each(x,...)
... kb.each(example, title, "foo")
<yvesr> JeniT, cool :) does it integrate with jquery as well? (rdflib.js)
timbl: kb.the(x, the, ..., g) to query a specific graph
<yvesr> JeniT, ah yes, it looks like it
<oberger> is anyone recording timbl ?
timbl: kb.the(s, p, o, g) and g
is the document, like GRAPH keyword in SPARQL
... and this might write the result straight back to the
graph
... this would be nice and short. can probably be
improved
... can people make it shorter and quicker? send SPARQL strings
to it as people may prefer to write SPARQL?
<rblin> I implement a small application wich use rdflib.js http://romainblin.net/lifeshare-4.0
<betehess> http://www.w3.org/TR/rdf-api/
ivan: we did try to get something rolling in the API space, and failed
<rblin> Just type the uri per example : http://bblfish.net/people/henry/card#me
ivan: there was a WG where we wanted to define APIs for RDF and RDFa
<rblin> and click to connexion to explore the foaf graph
<betehess> http://www.w3.org/TR/rdfa-api/
ivan: there were two or three
drafts published
... but there was no interest from the public in terms of the
public in coming and working with us, and no interest from the
browser vendors
... so we published them as W3C Notes
... there is a community group to pick this up, but it's
dormant
Ruben: Big mismatch between the
model that programmers use and RDF
... and no borders between objects. it's more fluid
... they prefer working with more enclosed, synchronous
objects
ivan: JSON-LD work has two sides
to it
... 1. it represents RDF graphs
... 2. it also defines a simple API
<betehess> http://www.w3.org/TR/json-ld-api/
ivan: the jury is still out
<Zakim> betehess, you wanted to mention efforts on the server-side
betehess: JS is very important,
but in my case I also need things server-side
... for example I want to say, this user can access the
resource and this one not. rules for access control
... so if you define APIs, don't stop at the JS
oberger: +1 for not restricting to JS
betehess: In the client it's fine if your graph is mutable
<oberger> thx cygri
<Ruben> JS is just a (prominent) example of how people will do things: the issues experienced there will also occur with others
betehess: on the server side, we may need immutable graphs
<oberger> betehess, and we should not restrict to JSON either and think about Turtle
sandro: There is DOM which is the standard, then there's jQuery that's a lot better/shorter
betehess: DOM is low-level. Like
assembly language.
... then there's highlevel stuff, but that's maybe not for
W3C
timbl: DOM tries to be
language-independent
... great in an environment with global symbol table where you
compile to C
... but in JS you want short names as everything is locally
scoped
... job to do is to optimize for particular languages
<betehess> if people are interested in APIs on the JVM (Java, Scala), I'm the main contributor to https://github.com/w3c/banana-rdf
timbl: JS being an asynchronous environment also changes things
<oberger> are we running out of time ?
Ruben: People expect JSON to being synchronous, things don't suddenly show up in the JSON tree
betehess: [access control]
... group of users identified via URIs
... you may want to fetch data at runtime. This takes time.
Where to start?
... Maybe written data is not yet there but only in 10
seconds
tidoust: Closing remarks?
Norman Richter, Uni Leipzig
Norman: Involved with research on
PubSubHubbub
... access control on top of that
betehess: Talk to Alexandre Passant, he did RDF+PubSubHubbub
<BartvanLeeuwen> RDF in pussubhubbub SparqlPush
Alexandre: [OData]
... We were looking into extending OData or having a parallel
RDF service
... ideally only one service, with semantic information
bhyland: Talk to David Wood
tidoust: Adjourned!
<develD> Norman Richter: So my question was to put rdf in a feed and to push it with an access control enabled pubsubhubbub
This is scribe.perl Revision: 1.137 of Date: 2012/09/20 20:19:01 Check for newer version at http://dev.w3.org/cvsweb/~checkout~/2002/scribe/ Guessing input format: RRSAgent_Text_Format (score 1.00) Succeeded: s/Speiche/Speicher/ Succeeded: s/Arnaud/ArnaudLH/ Succeeded: s|http://json-ld.org/spec/latest/json-ld-api/|http://www.w3.org/TR/json-ld-api/| Succeeded: s/tidoust/betehess/ Found Scribe: cygri Inferring ScribeNick: cygri WARNING: No "Topic:" lines found. Present: Jim_Fuller FabGandon David_Lewis Alexandre Bertails Adrian_Bateman Sebastian Trueg Norman Richter Ruben Verborgh Steve Speicher Olivier Berger timbl ivan sandro David Wood Bernadette Hyland Got date from IRC log name: 31 Oct 2012 Guessing minutes URL: http://www.w3.org/2012/10/31-ld-dev-minutes.html People with action items: WARNING: No "Topic: ..." lines found! Resulting HTML may have an empty (invalid) <ol>...</ol>. Explanation: "Topic: ..." lines are used to indicate the start of new discussion topics or agenda items, such as: <dbooth> Topic: Review of Amy's report[End of scribe.perl diagnostic output]