- From: Jarno van Driel <jarnovandriel@gmail.com>
- Date: Sun, 20 Apr 2014 21:03:46 +0200
- To: Gregg Kellogg <gregg@greggkellogg.net>
- Cc: Larry Betts <lbetts@thoughtwm.com>, "Dr. Richard H. McCullough" <rhm@pioneerca.com>, Niklas Lindström <lindstream@gmail.com>, public-rdfa <public-rdfa@w3.org>
- Message-ID: <CADK2AU1bgVSN+5wEXeQ1V3XsDs+VEmAeZbV2OOBpkLYxdK9r7A@mail.gmail.com>
"You (and others) might find my..."
I'll most definitely have a look at it at a quieter moment. Thanks for
pointing it out Dan. I'll get back to you about it.
"...This allows us to distinguish between a page about something, and that
thing"
I need to let this sink in, together with working through Dan's tutorial.
I'll give a progress update again when I worked through it.
Thanks again, more soon... :)
2014-04-20 19:16 GMT+02:00 Gregg Kellogg <gregg@greggkellogg.net>:
> On Apr 18, 2014, at 7:39 AM, Jarno van Driel <jarnovandriel@gmail.com>
> wrote:
>
> "Note that RDFa does not pass Alice..."
> mmm. probable a copy paste error because when I ran it though RDFa play
> the 'creator' had both the value Alice as well as that it was linking to
> the Person. Ran it through again and now it doesn't show Alice. Good to
> know though there is no difference in the data that gets parsed.
>
> "RDFa email does not get set"
> Good eye, I had missed that one.
>
> "The telephone example is odd..."
> That's because of different reasons than semantics. On most sites I
> maintain the @href contains a different value than the <span>. I follow ISO
> standards for defining the email address and phone number on the @href so
> when you activate them on mobile devices it automatically start your mail
> app or starts to dial. So I have to include their human readable versions
> in an extra span.
>
> "Also, in both cases, you use #me..."
> #me is in there because I copied it from Niklas's example. To be honest I
> haven't got a clue yet as to when use # and when not, simply because I
> haven't looked into it yet. I already was dancing around the table to
> finally get this far. Because I'm finally starting to make sense of the
> similarities between Microdata and RDFa not only my Microdata markup is
> improving but have I also become interested again in trying to understand
> RDFa (finally). So for now I'm enjoying the moment, even though I know I'm
> not there yet. Much to learn still.
> And be careful with what you make me understand, before you know it I'll
> be asking about OWL as well. ;)
>
>
> The use of fragment-based identifiers, such as #me, is intended to relate
> URIs that mean different things together. For example, my profile page is
> http://greggkellogg.net/foaf. It is a PersonalProfilePage, and as such,
> the properties describe it as being a web resource. However, the purpose of
> the page is to describe me, but I'm not a web page! Bye using the fragment
> identifier model, I can assert things about
> http://greggkellogg.net/foaf#me, to say! for example, that I am a
> foaf:Person. This allows us to distinguish between a page about something,
> and that thing.
>
> In your example, you use a URI to describe the page (or Information
> Resource), but an unrelated fragment identifier to describe the person
> (Non-Information Resource). It's not wrong, but you probably want them more
> closely related to each other.
>
> One way to so this is to set the base in the head of the HTML, and use
> everything else as being directly relative to that; this happens implicitly
> based on the location of the page, but this ties it down so that it has the
> same meaning, for instance, when you use it as an example.
>
> Gregg
>
> Thanks for all the help thoug: http://www.w3.org/TR/xhtml-rdfa-primer/ is
> actually starting to make sense to me because of it.
>
> Is there any sense in me trying to wrap my head around it's predecessor (
> http://www.w3.org/2006/07/SWD/RDFa/primer/) as well or is it too oudated?
>
>
> 2014-04-18 2:31 GMT+02:00 Gregg Kellogg <gregg@greggkellogg.net>:
>
>> On Apr 17, 2014, at 4:48 AM, Jarno van Driel <jarnovandriel@gmail.com>
>> wrote:
>>
>> I think I've figured it out:
>>
>> RDFa:
>> <div vocab="http://schema.org/" resource="/alice/posts/trouble_with_bob"
>> typeof="WebPage">
>> <h2 property="name">The trouble with Bob</h2>
>> <h3 property="creator" resource="#me">Alice</h3>
>> ...
>>
>> <div resource="#me" typeof="Person">
>> <p>
>> <span property="name">Alice Birpemswick</span>,
>> Email: <a href="mailto:alice@example.com"><span itemprop="email">
>> alice@example.com</span></a>,
>> Phone: <a href="tel:+1-617-555-7332"><span property="telephone">+1
>> 617.555.7332</span></a>
>> </p>
>> ...
>> </div>
>> </div>
>>
>> Microdata:
>> <div itemid="/alice/posts/trouble_with_bob" itemscope itemtype="
>> http://schema.org/WebPage">
>> <h2 itemprop="name">The trouble with Bob</h2>
>> <h3><link itemprop="creator" href="#me">Alice</h3>
>> ...
>>
>> <div itemid="#me" itemscope itemtype="http://schema.org/Person">
>> <p>
>> <span itemprop="name">Alice Birpemswick</span>,
>> Email: <a href="mailto:alice@example.com"><span itemprop="email">
>> alice@example.com</span></a>,
>> Phone: <a href="tel:+1-617-555-7332"><span itemprop="telephone">+1
>> 617.555.7332</span></a>
>> </p>
>> ...
>> </div>
>> </div>
>>
>>
>> It’s always worth distilling the markup to make sure you’re getting what
>> you expect. The RDFa translates to the following:
>>
>> @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
>> @prefix rdfa: <http://www.w3.org/ns/rdfa#> .
>> @prefix schema: <http://schema.org/> .
>> @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
>>
>> <> rdfa:usesVocabulary schema: .
>>
>> </alice/posts/trouble_with_bob> a schema:WebPage;
>> schema:creator <#me>;
>> schema:name "The trouble with Bob" .
>>
>> <tel:+1-617-555-7332> schema:telephone "+1 617.555.7332" .
>>
>> <#me> a schema:Person;
>> schema:name "Alice Birpemswick” .
>>
>> Microdata generates the following:
>>
>> @prefix md: <http://www.w3.org/ns/md#> .
>> @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
>> @prefix rdfa: <http://www.w3.org/ns/rdfa#> .
>> @prefix schema: <http://schema.org/> .
>> @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
>>
>> <> md:item (</alice/posts/trouble_with_bob> <#me>);
>> rdfa:usesVocabulary schema: .
>>
>> </alice/posts/trouble_with_bob> a schema:WebPage;
>> schema:creator (<#me>);
>> schema:name "The trouble with Bob" .
>>
>> <#me> a schema:Person;
>> schema:email "alice@example.com";
>> schema:name "Alice Birpemswick";
>> schema:telephone "+1 617.555.7332” .
>>
>> Differences:
>> - RDFa: property="creator" passes the value 'Alice' as well as creating a
>> triple (WebPage - creator - Person)
>> - Microdata: itemprop="creator" passes no value and only creates a
>> triple
>>
>>
>> Note that RDFa does not pass Alice, as the value of the creator property
>> comes from the @resource. Microdata gets much the same, except’s its in a
>> list, likely due to the Microdata registry settings.
>>
>> - RDFa: This type of triple can be made by using @resource on any HTML
>> element
>> - Microdata: This type of triple can only be made when using <link>
>> or <a> because there has to be a @href
>>
>>
>> Yes, but note that there are some other unexpected things going on here.
>>
>> RDFa email does not get set, as you use @itemprop, where you probably
>> intended @property.
>>
>> The telephone example is odd, as the <a> element set’s the subject from
>> @href, which is used within the span; you need to take care that the
>> subject remains what you expect.
>>
>> Also, in both cases, you use #me, which is fine, but it means it’s
>> relative to the webpage URL, and not the id you set for the WebPage type.
>>
>> Conclusion:
>> The meaning of @resource changes depending on the way it's used. In
>> Microdata this requires different markup:
>> property + @resource (no typeof) == property + @href
>> @resource + typeof == @itemid + itemscope = itemtype
>>
>> Is this correct and/or did I miss anything?
>>
>>
>> Actually, they’re both pretty much the same:
>>
>> @resource + @typeof == @itemid + @itemscope + @itemtype
>> @property + @href = @itemprop + @itemid + @itemscope
>> @property + @href + @typeof = @itemprop + @itemid + @itemscope +
>> @itemtype.
>>
>> Gregg
>>
>> 2014-04-17 12:14 GMT+02:00 Jarno van Driel <jarnovandriel@gmail.com>:
>>
>>> Thanks for explaining the comparison between the two.
>>>
>>> *"RDFa behaves differently if the element contains both @resource and
>>> @property"*
>>> I won't ask you about this yet Gregg because I've got plenty of reading
>>> to do still and want to see if I can figure out what's behind it myself.
>>> But I'm going to keep it in the back of my head in case I don't.
>>>
>>>
>>> 2014-04-17 1:16 GMT+02:00 Gregg Kellogg <gregg@greggkellogg.net>:
>>>
>>> On Apr 16, 2014, at 1:47 PM, Jarno van Driel <jarnovandriel@gmail.com>
>>>> wrote:
>>>>
>>>> I wouldn't actually know. I just am starting to wrap my head around
>>>> @resource, @rev and @rel. Haven't had time to look into @about as well.
>>>> Maybe somebody else can say something more educated about that?
>>>>
>>>>
>>>> @itemid is essentially the same as @resource; when interpreting
>>>> Microdata as RDF, it sets the subject of the triples for that @itemscope.
>>>> It must be used on the same element as @itemscope and @itemtype. If you
>>>> also have @itemprop on that element, the identifier will be set as the
>>>> object of a triple relating to a previous item using the specified property.
>>>>
>>>> RDFa behaves differently if the element contains both @resource and
>>>> @property
>>>>
>>>> Gregg
>>>>
>>>> 2014-04-16 22:45 GMT+02:00 Larry Betts <lbetts@thoughtwm.com>:
>>>>
>>>>> That's some great information Jarno! Would "itemid" be an analog to
>>>>> the RDFa "reference"/"about"?
>>>>>
>>>>> Regards,
>>>>>
>>>>> *Larry P. Betts*
>>>>> Search Engine Marketing Specialist
>>>>>
>>>>> Thoughtwire Marketing LLC
>>>>> PO BOX 8077
>>>>> Mansfield, OH 44907
>>>>> Phone: 877-848-9581 Ext. 1055
>>>>> Direct: 419-610-2076
>>>>> Fax: 440-209-7783
>>>>> Email: lbetts@thoughtwm.com <pfernando@thoughtwm.com>
>>>>> Web: http://www.thoughtwiremarketing.com <http://www.thoughtwm.com/>
>>>>>
>>>>>
>>>>> On Wed, Apr 16, 2014 at 4:23 PM, Jarno van Driel <
>>>>> jarnovandriel@gmail.com> wrote:
>>>>>
>>>>>> Hey folks,
>>>>>>
>>>>>> I just wanted you to know that after the last mailing I have been
>>>>>> doing quite some reading as well extensive testing and am happy to inform
>>>>>> you that Google now fully supports @itemid as global identifier and that
>>>>>> linking to it actually works!
>>>>>>
>>>>>> Not only do I get the right results in Google's Structured data
>>>>>> testing tool but in also Webmaster tools. I've been testing with @itemid on
>>>>>> my own site, by having multiple objects link to the same entity, as well
>>>>>> creating cycles by having entities point to each other, and everything
>>>>>> returns the proper values and types.
>>>>>>
>>>>>> I have reworked the example Niklas provided in Microdata so you can
>>>>>> see yourself:
>>>>>> (don't feel like reading the code? than look at what the SDTT makes
>>>>>> of it: http://bit.ly/1jLitKl)
>>>>>>
>>>>>> <body itemid="page" itemscope itemtype="http://schema.org/ItemPage">
>>>>>> <link itemprop="copyrightHolder" href="corp">
>>>>>>
>>>>>> <article itemprop="text">
>>>>>> <div itemid="article" itemscope itemtype="
>>>>>> http://schema.org/Article">
>>>>>> <link itemprop="publisher" href="corp">
>>>>>>
>>>>>> <h1 itemprop="name">How to copy properties in RDFa Lite &
>>>>>> Microdata</h1>
>>>>>> </div>
>>>>>> </article>
>>>>>>
>>>>>> <footer itemprop="mentions" itemscope itemtype="
>>>>>> http://schema.org/WPFooter">
>>>>>> <p>
>>>>>> <span itemid="corp" itemprop="about" itemscope itemtype="
>>>>>> http://schema.org/Corporation">
>>>>>> <a itemprop="url" href="http://www.example.org">
>>>>>> <span itemprop="name">Corporation name</span>
>>>>>> </a>
>>>>>>
>>>>>> <span itemprop="description">Corporation description</span>
>>>>>> </span>
>>>>>> </p>
>>>>>> </footer>
>>>>>> </body>
>>>>>>
>>>>>> Thanks for all the great input you have given me! I actually have
>>>>>> hope again that I will be able to make sense of RDFa because of it. :)
>>>>>>
>>>>>>
>>>>>> 2014-03-11 19:02 GMT+01:00 Richard H. McCullough <rhm@pioneerca.com>:
>>>>>>
>>>>>> You might want to steal some ideas from the mKR language.
>>>>>>>
>>>>>>> mKR lets you name any list of propositions, e.g.,
>>>>>>> my propositions :: { proposition list };
>>>>>>> and manipulate that list in numerous ways.
>>>>>>>
>>>>>>> You can add, delete, ... propositions
>>>>>>> You can change the underlying class hierarchy
>>>>>>> ...
>>>>>>>
>>>>>>> *Dick McCullough *
>>>>>>> Context Knowledge Systems<http://mkrmke.org/ContextKnowledgeSystems.html>
>>>>>>> mKE and the mKR language <http://mkrmke.org/mKEmKR.html>
>>>>>>> mKR/mKE tutorial <http://mkrmke.org/doc/MKEtutorial.html>
>>>>>>>
>>>>>>> ------------------------------
>>>>>>> Date: Tue, 11 Mar 2014 15:41:09 +0100
>>>>>>> From: jarnovandriel@gmail.com
>>>>>>> To: gregg@greggkellogg.net
>>>>>>> CC: lindstream@gmail.com; public-rdfa@w3.org
>>>>>>> Subject: Re: how do I copy some properties that are part of a bigger
>>>>>>> pattern
>>>>>>>
>>>>>>>
>>>>>>> Thanks for the sources Gregg. Some of 'm I know but with the new
>>>>>>> insights I have now I bet some of 'm will make much more sense to me now.
>>>>>>> I'll make sure to read it before asking more questions.
>>>>>>>
>>>>>>>
>>>>>>> 2014-03-11 2:01 GMT+01:00 Gregg Kellogg <gregg@greggkellogg.net>:
>>>>>>>
>>>>>>> On Mar 10, 2014, at 5:07 AM, Jarno van Driel <
>>>>>>> jarnovandriel@gmail.com> wrote:
>>>>>>>
>>>>>>> "...There is no difference here between links and "nested" items..."
>>>>>>> + "...Try the example..."
>>>>>>> Thanks, you just made my brain explode. =)
>>>>>>>
>>>>>>> It's been a couple of years since my first attempts at understanding
>>>>>>> RDFa - which failed miserably - since I have difficulty translating the W3
>>>>>>> specifications in, for me, understandable rules on how it's supposed to be
>>>>>>> used and what it can do. Your comments together with the RDFa Play outcome
>>>>>>> succeeded where countless hours of reading specifications and experimenting
>>>>>>> with markup have failed me. Seriously Niklas, thanks!
>>>>>>>
>>>>>>> Now as for the IRC meet, let that slide for now. A tsunami of
>>>>>>> possibilities just flushed over me and I have to give it some time to let
>>>>>>> it sink in. The first thought I had after reading your comments and seeing
>>>>>>> the RDFa Play outcome was that writing an article about the use of @itemref
>>>>>>> isn't that difficult but comparing that to rdfa:pattern just became a whole
>>>>>>> lot more complicated. It now has become clear to me there is no 1:1
>>>>>>> relation between the two - where I thought there was - and that RDFa offers
>>>>>>> different solutions for many of the situations where one only can use
>>>>>>> @itemref in Microdata. Which IS marvelous but which leaves me confused in
>>>>>>> how to clarify that in an article without writing a series that's as thick
>>>>>>> as the bible.
>>>>>>>
>>>>>>>
>>>>>>> There are some great discussion threads on public-rdfa-wg in around
>>>>>>> December 2012, starting with a proposal from Ivan. Check out the
>>>>>>> "Reproducing Gregg/Niklas' thoughts ..." thread in
>>>>>>> http://lists.w3.org/Archives/Public/public-rdfa-wg/2012Dec/thread.html
>>>>>>> .
>>>>>>>
>>>>>>> As Niklas points out, the original concept was that a semantic
>>>>>>> approach to property-copying, where we identified a resource and used it as
>>>>>>> the source for copying properties, and remove the original "template"
>>>>>>> resource. Basically, it could mostly be done using SPARQL with INSERT
>>>>>>> DATA/DELETE DATA. It's worth looking at the thread to see some of the
>>>>>>> thought processes that were going on at the time.
>>>>>>>
>>>>>>> I do know however that I want to limit myself to RDFa Lite since
>>>>>>> it's the RDFa community's answer to Microdata. Or at least that's way I
>>>>>>> understand it. So let me therefore ask, what are the differences between
>>>>>>> RDFa and RDFa Lite? Is there any clear documentation about the difference
>>>>>>> between the two I can read?
>>>>>>>
>>>>>>>
>>>>>>> The RDFa Lite 1.1 recommendation <http://www.w3.org/TR/rdfa-lite/>
>>>>>>> pretty much calls this out. Also, the RDFa 1.1 Primer <
>>>>>>> http://www.w3.org/TR/xhtml-rdfa-primer/>. The key observation to
>>>>>>> the LIte recommendation is that RDFa gets complicated when there are too
>>>>>>> many attributes on an element, and the distinction between @about and
>>>>>>> @resource can be subtle. Even now, I see people having a problem with
>>>>>>> Microdata, when they use @itemprop on an anchor, and seem to expect the
>>>>>>> content of the element, rather than the value of @href to be used as the
>>>>>>> property's value. RDFa suffers from the same issue, but things get simpler
>>>>>>> when you restrict yourself to using fewer attributes and avoid combining
>>>>>>> them together.
>>>>>>>
>>>>>>> That said, there is quite a bit of power in full RDFa 1.1,
>>>>>>> particularly in the use of lists and chaining <
>>>>>>> http://www.w3.org/TR/rdfa-core/#s_chaining>. Chaining is really
>>>>>>> useful when you have a number of resource values from the same property,
>>>>>>> for example the author list of a document. This avoids repeating markup,
>>>>>>> but it is a sophisticated feature. IMO, you really can't write RDFa (full
>>>>>>> or lite) or Microdata without running it through a distiller to verify that
>>>>>>> it says what you mean.
>>>>>>>
>>>>>>> Let me widen the question: Are there any sources you guys can
>>>>>>> recommend me to read about RDFa (Lite)?
>>>>>>> Like I said earlier, it's been a couple of years for me, so I hope
>>>>>>> new documentation exists by now, besides the W3 specifications.
>>>>>>>
>>>>>>>
>>>>>>> Manu wrote a great post on the differences between RDFa Lite and
>>>>>>> Microdata: <http://manu.sporny.org/2012/mythical-differences/>.
>>>>>>>
>>>>>>> Gregg
>>>>>>>
>>>>>>> 2014-03-09 18:10 GMT+01:00 Niklas Lindström <lindstream@gmail.com>:
>>>>>>>
>>>>>>> Hi Jarno,
>>>>>>>
>>>>>>> On Sun, Mar 9, 2014 at 5:08 PM, Jarno van Driel <
>>>>>>> jarnovandriel@gmail.com> wrote:
>>>>>>>
>>>>>>> "...outputs two different nodes for what seemingly is the same
>>>>>>> corporation..."
>>>>>>> You're right in stating that this results in two instances of the
>>>>>>> same Corporation. Which is the only way in Microdata to have an Item
>>>>>>> (Corporation) be linked to other Items by means of different properties
>>>>>>> (copyrightHolder & publisher). The following markup simply wouldn't work in
>>>>>>> Microdata:
>>>>>>> <div itemprop="manufacturer" itemref="corporation-data">
>>>>>>>
>>>>>>>
>>>>>>> Yes, microdata (presumably) being a tree model prevents it from
>>>>>>> connecting items together naturally. It's a big flaw. It only deals with
>>>>>>> surface data, and says nothing about what it means. Perhaps @itemid makes
>>>>>>> it into some kind of graph at times though, it's hard to tell when there
>>>>>>> are no semantics explaining what that entails.
>>>>>>>
>>>>>>>
>>>>>>> In Microdata itemref can only get additional info about a Type. You
>>>>>>> can't use it on a property and then use itemref to get the @itemtype
>>>>>>> elsewhere. That's why in Microdata I have to declare the Corporation twice,
>>>>>>> to be able to link it to different entities (ItemPage & Article) by means
>>>>>>> of different properties (copyrightHolder & publisher). Which brings me to
>>>>>>> the question: Can this be accomplished RDFa Lite where it can't in
>>>>>>> Microdata? - keeping in mind that in this specific example according to
>>>>>>> schema.org rules the publisher and copyrightHolder are both
>>>>>>> expected to 'have' a type and are not supposed to 'link' to a type.
>>>>>>>
>>>>>>>
>>>>>>> Yes, it can. RDFa uses the RDF data model, which is a graph [1].
>>>>>>> There is no difference here between links and "nested" items. You type and
>>>>>>> (when needed) identify things, link them together and describe their
>>>>>>> details with literals (texts) – all using properties. That is what I did in
>>>>>>> the example given.
>>>>>>>
>>>>>>>
>>>>>>> "...<p resource="#page">
>>>>>>> <span property="copyrightHolder" typeof="Corporation"
>>>>>>> resource="#corp">..."
>>>>>>> The downside to this method is that the copyrighHolder-Corporation
>>>>>>> now gets linked falsely. I quickly checked the output in Google's SDTT,
>>>>>>> which showed the Corporation being a child of the WPFooter as opposed to
>>>>>>> being the copyrightHolder of the ItemPage. The use of rdfa:pattern prevents
>>>>>>> this happening as does a itemscope without an itemtype in Microdata e.g.
>>>>>>> <div itemscope>.
>>>>>>>
>>>>>>>
>>>>>>> The Google SDTT is wrong. It should recognize that <p
>>>>>>> resource="#page"> sets the subject for nested statements (here ensuring
>>>>>>> that the <#page> has the <#corp> as :copyrightHolder). It seems that adding
>>>>>>> a @typeof:
>>>>>>>
>>>>>>> <p resource="#page" typeof="ItemPage">
>>>>>>>
>>>>>>> makes it behave somewhat more as expected. But note that that isn't
>>>>>>> necessary in RDFa, it's just a workaround for a bug in the SDTT. (Try the
>>>>>>> example out in e.g. <http://rdfa.info/play/> to see it more
>>>>>>> clearly.)
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> "Also, the resulting data here doesn't contain two distinct nodes
>>>>>>> for what is apparently meant to be the same corporation."
>>>>>>> True, but the two distinct nodes also have type-specific relations
>>>>>>> to the two distinct items this example has, namely ItemPage and Article.
>>>>>>> Maybe that info got a bit lost because I stripped out so much of the
>>>>>>> original HTML. The source I took this from has an ItemPage with a gazillion
>>>>>>> other types attached to it while the Article is just that, an Article, with
>>>>>>> it's own set of properties, mostly separated from the rest of the content
>>>>>>> on the ItemPage, only sharing data from the Corporation.
>>>>>>>
>>>>>>>
>>>>>>> I think I see how you mean. But if you think of this in terms of the
>>>>>>> RDF data model, the items simply are resources linked together (and
>>>>>>> assigned some types, and described with textual properties), rather than
>>>>>>> blocks of data tied to the page structure (or the microdata tree structure,
>>>>>>> which hardly helps). In this model, the corporation is surely one thing,
>>>>>>> connected to from the ItemPage using copyrightHolder, and from the Article
>>>>>>> using publisher (both of which are fine since the thing linked to is of the
>>>>>>> expected type).
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> "I'd be happy to take a look at such examples as well."< br>
>>>>>>> Maybe we should meet in an IRC session, like Gregg suggested,
>>>>>>> because I'm convinced we can keep this argument-counterargument up for
>>>>>>> quite some time. Not that I mind, since this mailing has already given me a
>>>>>>> ton to think about, but simply to be more time-efficient. Just let me know
>>>>>>> what you guys prefer, either way is fine with me.
>>>>>>>
>>>>>>>
>>>>>>> I'm fine either way too. :) I tend to have intermittent bouts of
>>>>>>> time, so mailing is usually better for examples. But I could go for a chat
>>>>>>> over specifics if needed.
>>>>>>>
>>>>>>> Cheers,
>>>>>>> Niklas
>>>>>>>
>>>>>>> [1]: http://www.w3.org/TR/rdf11-primer/
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> 2014-03-09 14:19 GMT+01:00 Niklas Lindström <lindstream@gmail.com>:
>>>>>>>
>>>>>>> Hi Jarno and Gregg!
>>>>>>>
>>>>>>> It seems to me that this is a good example of where @itemref-like
>>>>>>> functionality is quite unnecessary in RDFa. The #copyright-holder simply
>>>>>>> contains a link from the page to the corporation, and the #publisher-url
>>>>>>> and #publisher-description contain properties of that corporation. The
>>>>>>> resulting microdata, however, outputs two different nodes for what
>>>>>>> seemingly is the same corporation, so perhaps the example has been
>>>>>>> simplified too much, thus obscuring what is actually needed?
>>>>>>>
>>>>>>> Still, In RDFa, instead of adding different @id:s to disparate parts
>>>>>>> of the page which are about the same resource (and then listing them in
>>>>>>> @itemref), you simply use @resource to capture the fact that a given block
>>>>>>> is about it.
>>>>>>>
>>>>>>> Your example can thus be written like this in RDFa Lite:
>>>>>>>
>>>>>>> - - - 8< - - -
>>>>>>>
>>>>>>> <body vocab="http://schema.org/" typeof="ItemPage" resource="#page">
>>>>>>> <article property="text">
>>>>>>> <div typeof="Article">
>>>>>>> <link property="publisher" resource="#corp">
>>>>>>>
>>>>>>> <h1 property="name">How to copy properties in RDFa Lite &
>>>>>>> Microdata</h1>
>>>>>>> </div>
>>>>>>> </article>
>>>>>>>
>>>>>>> <footer property="mentions" typeof="WPFooter">
>>>>>>> <div property="text">
>>>>>>> <p resource="#page">
>>>>>>> <span property="copyrightHolder" typeof="Corporation"
>>>>>>> resource="#corp">
>>>>>>> <a property="url" href="http://www.example.org">
>>>>>>> <span property="name">Corporation name</span>
>>>>>>> </a>
>>>>>>>
>>>>>>> <span property="description">Corporation description</span>
>>>>>>> </span>
>>>>>>> </p>
>>>>>>> </div>
>>>>>>> </footer>
>>>>>>> </body>
>>>>>>>
>>>>>>> - - - >8 - - -
>>>>>>>
>>>>>>> In my opinion, this is a more convenient way of handling data
>>>>>>> smeared out in a messy tag soup (with the results being shorter and more
>>>>>>> legible). Of course, you need to name these resources, unless they already
>>>>>>> have formal URIs, but that's easily done with a fragment identifier or a
>>>>>>> bnode id. (And note that in microdata, you instead need to ensure that a
>>>>>>> layout designer doesn't meddle with the @id values used by @itemref, for
>>>>>>> quite different reasons (their use in CSS and JS).)
>>>>>>>
>>>>>>> Also, the resulting data here doesn't contain two distinct nodes for
>>>>>>> what is apparently meant to be the same corporation.
>>>>>>>
>>>>>>> Remember, it is only when you need to duplicate a set of properties
>>>>>>> for different resources that rdfa:copy is necessary. And even in those
>>>>>>> circumstances, you might be able to leverage the way @resource can group
>>>>>>> descriptions together, to build up one pattern from disparate parts of the
>>>>>>> page.
>>>>>>>
>>>>>>> I'd be happy to take a look at such examples as well.
>>>>>>>
>>>>>>> Cheers,
>>>>>>> Niklas
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Sun, Mar 9, 2014 at 11:51 AM, Jarno van Driel <
>>>>>>> jarnovandriel@gmail.com> wrote:
>>>>>>>
>>>>>>> I think your and my latest example just passed each other Gregg. I
>>>>>>> guess I posted mine when you were writing yours because when I compare the
>>>>>>> two I see we implemented the same workaround by means of additional
>>>>>>> @resource.
>>>>>>>
>>>>>>> "I wouldn't recommend the use of included patterns in RDFa, but it
>>>>>>> can be made to work."
>>>>>>> I wouldn't recommend it either but unfortunately the everyday
>>>>>>> website out there consists out of a HTML-soup which doesn't allow for
>>>>>>> Semantic markup to be added in a nice and clean way. Now I mainly work on
>>>>>>> already existing websites, where I have to make do with HTML that's already
>>>>>>> in place. Therefore itemref or rdfa:pattern are indispensable when
>>>>>>> organizing/linking data that's smeared out over many different HTML
>>>>>>> elements on a page. I am very aware this results in markup that isn't
>>>>>>> 'nice' but it helps create meaning even if the HTML is a mess.
>>>>>>>
>>>>>>> "P.S., I think it’s great that you’re trying to describe this for a
>>>>>>> wider audience!"
>>>>>>> Well, I'm not doing it alone. Aaron Bradley is acting as the devil's
>>>>>>> advocate by asking me questions which mess up the solutions I provide.
>>>>>>> Which in return forces me to come up with different solutions and ask a lot
>>>>>>> of questions at the public-vocabs (and now here as well). :)
>>>>>>>
>>>>>>> So trying to do something for a bigger audience will most definitely
>>>>>>> end up in something that has been contributed by many people. As always
>>>>>>> this kind of stuff ends up being a multi-community/person effort since it
>>>>>>> brings together so many different specializations and specifications.
>>>>>>>
>>>>>>> --
>>>>>>>
>>>>>>> Andy and Gregg,
>>>>>>> Thanks for sharing your knowledge, I'll make sure re-share it and am
>>>>>>> hopeful it will result in an article (or series of) which will try to serve
>>>>>>> anybody who is (or should be) interested in this type of info.
>>>>>>>
>>>>>>>
>>>>>>> 2014-03-09 6:46 GMT+01:00 Gregg Kellogg <gregg@greggkellogg.net>:
>>>>>>>
>>>>>>> On Mar 8, 2014, at 5:50 PM, Jarno van Driel <jarnovandriel@gmail.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>> "..the @resource attributes get in the way.."
>>>>>>> Could you explain this to me a bit more please Gregg? Because if I
>>>>>>> parse my last markup through the Structured data linter and RDFa Play I get
>>>>>>> 100% the same outcome as with your markup. Yandex and Google see the same
>>>>>>> data as well (in a ever so slightly different manner).
>>>>>>>
>>>>>>> When I look at the output these parsers have no trouble extracting
>>>>>>> the @resources as different rdfanodes. Unless I'm completely overlooking
>>>>>>> something, or am breaking some cardinal rules, which both are feasible
>>>>>>> since I just got around to looking more deeply into RDFa Lite.
>>>>>>>
>>>>>>>
>>>>>>> In order to be able to reference the publisher-uri and
>>>>>>> publisher-description information as patterns, they need to have an
>>>>>>> identifier, which I supplied by adding @resource (and
>>>>>>> @typeof=“rdfa:Pattern) to each. However, this changes the scope of their
>>>>>>> properties relative to the copyright-holder.
>>>>>>>
>>>>>>> In you’re RDFa version you weren’t able to access the publisher-uri
>>>>>>> or publisher-description, as you do from Microdata. The RDFa property
>>>>>>> copying uses a resource of type rdfa:Pattern, which must be identified as a
>>>>>>> resource. For this reason, I added the @resource and @typeof for both the
>>>>>>> publisher-description and publisher-url. However, doing that, changes the
>>>>>>> current subject for each of these, so the “url” and “description”
>>>>>>> properties are allocated to different resources. To get around this, I
>>>>>>> added the rdfa:copy properties both the the publisher reference, and to the
>>>>>>> copyright-holder, so that the properties appear in each of them. I wouldn’t
>>>>>>> recommend the use of included patterns in RDFa, but it can be made to work.
>>>>>>>
>>>>>>> I’d recommend both for Microdata and RDFa to keep references simple,
>>>>>>> and using included references, while possible, can make things more
>>>>>>> confusing. This is certainly not a pattern we were concerned about when
>>>>>>> crafting the property copying mechanism in HTML+RDFa. They two really work
>>>>>>> quite differently: Microdata requires full access to the DOM so that
>>>>>>> referenced elements can be copied, which requires random access to the DOM.
>>>>>>> The RDFa mechanism operates at a semantic level, by creating triples as
>>>>>>> normal. RDFa is intended to work with streaming processors, where there is
>>>>>>> no random-access to the DOM. The spec provides details of the rules which
>>>>>>> are applied to achieve the effect of property copying [1], but it’s not
>>>>>>> really magic to RDFa, and could just as easily be done for triples
>>>>>>> extracted from Turtle, or even Microdata, if the appropriate copying rules
>>>>>>> were applied.
>>>>>>>
>>>>>>> I understood that you didn’t know how to deal with a pattern
>>>>>>> embedded in another pattern, which I attempted to address for you. I think
>>>>>>> that the RDFa I provided does essentially what your Microdata does. If you
>>>>>>> want to discuss more, we should probably meet on IRC.
>>>>>>>
>>>>>>> Gregg
>>>>>>>
>>>>>>> P.S., I think it’s great that you’re trying to describe this for a
>>>>>>> wider audience!
>>>>>>>
>>>>>>> [1] http://www.w3.org/TR/rdfa-in-html/#implementing-property-copying
>>>>>>>
>>>>>>>
>>>>>>> 2014-03-09 1:33 GMT+01:00 Gregg Kellogg <gregg@greggkellogg.net>:
>>>>>>>
>>>>>>> Hi Jarno, I don’t think you can do precicely what you want, since if
>>>>>>> a pattern is included in another pattern, the @resource attributes get in
>>>>>>> the way. You can do it by adding some more rdfa:copy properties. This is
>>>>>>> what I came up with:
>>>>>>>
>>>>>>> <body vocab="http://schema.org/" resource="#item-page"
>>>>>>> typeof="ItemPage">
>>>>>>> <link property="rdfa:copy" href="#copyright-holder">
>>>>>>>
>>>>>>> <article property="text">
>>>>>>> <div resource="#article" typeof="Article">
>>>>>>> <div property="publisher" typeof="Corporation">
>>>>>>> <link property="rdfa:copy" href="#publisher-url"/>
>>>>>>> <link property="rdfa:copy" href="#publisher-description"/>
>>>>>>> </div>
>>>>>>>
>>>>>>>
>>>>>>> <h1 property="Name">How to copy properties in RDFa Lite &
>>>>>>> Microdata</h1>
>>>>>>> </div>
>>>>>>> </article>
>>>>>>>
>>>>>>> <footer property="mentions" typeof="WPFooter">
>>>>>>> <div property="text">
>>>>>>> <p resource="#copyright-holder" typeof="rdfa:Pattern">
>>>>>>> <span property="copyrightHolder" typeof="Corporation">
>>>>>>> <link property="rdfa:copy" href="#publisher-url"/>
>>>>>>> <link property="rdfa:copy" href="#publisher-description"/>
>>>>>>> <span resource="#publisher-url" typeof="rdfa:Pattern">
>>>>>>> <a id="publisher-url" property="url" href="
>>>>>>> http://www.example.org" title>
>>>>>>> <span property="name">Corporation name</span>
>>>>>>> </a>
>>>>>>> </span>
>>>>>>>
>>>>>>> <span resource="#publisher-description"
>>>>>>> typeof="rdfa:Pattern">
>>>>>>> <span id="publisher-description"
>>>>>>> property="description">Corporation description</span>
>>>>>>> </span>
>>>>>>> </span>
>>>>>>> </p>
>>>>>>> </div>
>>>>>>> </footer>
>>>>>>> </body>
>>>>>>>
>>>>>>> Gregg Kellogg
>>>>>>> gregg@greggkellogg.net
>>>>>>>
>>>>>>> On Mar 8, 2014, at 2:37 PM, Jarno van Driel <jarnovandriel@gmail.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>> <body vocab="http://schema.org/" resource="#item-page"
>>>>>>> typeof="ItemPage">
>>>>>>> <link property="rdfa:copy" href="#copyright-holder">
>>>>>>>
>>>>>>> <article property="text">
>>>>>>> <div resource="#article" typeof="Article">
>>>>>>> <link property="publisher" typeof="Corporation" href=?????>
>>>>>>>
>>>>>>> <h1 property="Name">How to copy properties in RDFa Lite &
>>>>>>> Microdata</h1>
>>>>>>> </div>
>>>>>>> </article>
>>>>>>>
>>>>>>> <footer property="mentions" typeof="WPFooter">
>>>>>>> <div property="text">
>>>>>>> <p resource="#copyright-holder" typeof="rdfa:Pattern">
>>>>>>> <span property="copyrightHolder" typeof="Corporation">
>>>>>>> <a id="publisher-url" property="url" href="http://www.example.org"
>>>>>>> title>
>>>>>>> <span property="name">Corporation name</span>
>>>>>>> </a>
>>>>>>>
>>>>>>> <span id="publisher-description" property="description">Corporation
>>>>>>> description</span>
>>>>>>> </span>
>>>>>>> </p>
>>>>>>> </div>
>>>>>>> </footer>
>>>>>>> </body>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>>
>>>
>>
>>
>
Received on Sunday, 20 April 2014 19:04:16 UTC