- From: Sandro Hawke <sandro@w3.org>
- Date: Wed, 16 Jul 2014 20:01:07 -0400
- To: Kingsley Idehen <kidehen@openlinksw.com>,public-webid@w3.org
On July 16, 2014 7:41:02 PM EDT, Kingsley Idehen <kidehen@openlinksw.com> wrote: >On 7/16/14 12:23 PM, Sandro Hawke wrote: >> On 07/16/2014 12:06 PM, Kingsley Idehen wrote: >>> On 7/16/14 10:23 AM, Ruben Verborgh wrote: >>>> Hi Kingsley, >>>> >>>>> >Is there any reason why Turtle and JSON-LD cannot be on equal >>>>> footing in regards to the WebID spec? >>>>> > >>>>> >There's no reason why WebID-Profile documents MUST be comprised >of >>>>> RDF content in Turtle Notation. >>>> In general, several W3C specs demand the presence of a specific RDF > >>>> representation. >>>> (Linked Data Platform, R2RML, …) >>>> >>>> Seems indeed quite contradictory… why did we invent RDF in the >first >>>> place?:-) >>> >>> Exactly the question that hits me in the head every time I look at >an >>> RDF language (system of signs, syntax, and semantics) based spec >that >>> prefers a specific notation via MUST. >>> >>> >>>> >>>> On the other hand, I see some necessity for interoperability, but >>>> still… >>> >>> Interoperability isn't lost via Turtle and JSON-LD support in >WebID-* >>> . In fact, we increase interoperability via proper use of RDF and >>> AWWW :-) >>> >>> >> >> Imagine we have six different servers. Each of them is publishing >RDF >> in a W3C Recommended way. >> Server 1 provides only Turtle. Server 2 provides only RDF/XML. >Server >> 3 provides only n-quads. Server 4 provides only JSON-LD. Server 5 >> provides only RDFa. And just for good measure, server 6 provides >> only a custom format, but includes a transformation to RDF/XML via >GRDDL. > >And server 7 simply uses "Link:" relations in HTTP for RDF triples, and > >server 8 that publishes HTML documents with Microdata based RDF >tripoles, and server 9 that publishes HTML documents with RDFa based >triples, and server 10 that publishes HTML documents with POSH (Plain >Old Semantic HTML) based triples, etc.. > >> >> In this world, everyone is following W3C Recommendations, but now >> every client has to implement 5 RDF parsers plus a GRDDL >> transformation engine. > >GRDDL (which also came from the W3C, all examples XML based etc..), >plus >the other servers in my comments above magnify the problem. Who is the >source of these notations? The multiplicity of notations, and your >characterization are all part of the problem, I must painfully assert. > >> >> To me that seems like a huge blow to interoperability. > >Quite the contrary. You are leaving out the fundamental fact that HTTP >URIs is an integral part of AWWW and that content-negotiation is an >HTTP >feature. That said, I don't even see content-negotiation as the >solution >to the problem, its actually secondary. > >> How many clients are really going to do that, and do it properly? > >Clients request text/html from servers, most of the time. None of them >do what you characterize as "behaving properly" . > >Bearing in mind the reality above, why would any RDF based spec use >anything other than an HTML based notation as its mandatory notation? >At >the very least, all HTML browsers know how to fetch and process HTML. > >> If instead, everyone just published in Turtle, then clients would >only >> need to know how to read Turtle. > >I have written more Turtle than most, by hand. I think Turtle is by far > >the best notation for RDF, but none of that would make me support the >position above. > >HTML user agents are not going to be implementing Turtle parsers for >RDF. They are going to work with HTML based notations and JSON-LD (due >to the ubiquity of Javascript and the dominance of programmers in this >realm). > >It took Google nano seconds (relatively speaking) and zero evangelism >from JSON-LD supporters to adopt JSON-LD. Whether we like it or not, >what Google does matters, they provide the most widely used search >engine on the planet. The World Wide Web modulo Google Search is nearly > >as mercurial to appreciate (value proposition wise) as RDF. > >> That would make it so much easier to join the fun. > >Sorry, it won't. It hasn't happened so far, and this isn't how this >will >come to fruition. Turtle's real power emerges when relationships, >relations, and semantics are understood. That only happens when RDF is >properly understood, and after 13+ years, it is clear that the current >approach doesn't work i.e., stuffing Turtle (or RDF/XML in the past) >into RDF based specs behind a MUST. > >> >> Within LDP, the current compromise is every server MUST handle Turtle > >> (so clients can get by knowing only Turtle), and every server SHOULD >> ALSO handle JSON-LD (so most clients can probably get by knowing only > >> JSON-LD). Had JSON-LD been adopted slightly sooner, we probably >> would have said MUST on both. > >Yes, and when talking to implementers, we can effectively simulate a >MUST for both, by giving both equal and balanced coverage in examples. >Likewise, encouraging implementers to support both. > >> >> But LDP assumes a fairly smart server which knows about RDF. > >An RDF notation? >RDF the Language for structured data representation endowed with human >and machine comprehensible relation semantics? >Which RDF? >> To me that seems like rather a high burden for WebID publishers. > >How many WebID publishers are there today, after all of these years? > >How many WebID-TLS processors are there, after all of these years? > > >> If you want MUST on both, then you're forcing everyone who's doing >> this by hand to be able to do Con-Neg and to know both Turtle and >> JSON-LD. > >No, it simply means that two distinct profiles will build solutions, >and >in doing so they'll come to appreciate RDF and AWWW much more as they >hit issues with interoperability. Basically, you will have far more >implementations that exist today, and interoperability will be the >focal >point across implementations. > >> Seems kind of a burden to me. > >Not to me, I really disagree with this worldview, profoundly :-) > Indeed. Not much point in replying to the above. I agree with some bits and disagree with some bits. Not very relevant to WebID. >> Maybe worthwhile, but there's a real cost. > >The cost is a perception. The real cost calculation should be based on >the dearth of WebID-* implementations, since inception. Add that to all > >time spent explaining what WebID-* is about, after all of these years. > I think there are several reasons WebID and WebID-TLS have seen only meager adoption. I don't think what the specs say about RDF syntaxes are a big part of that. - Sandro >> >> -- Sandro >> >> >> >>
Received on Thursday, 17 July 2014 00:01:18 UTC