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Re: Microdata Issues [was Microdata design philosophies]

From: Martin McEvoy <martin@weborganics.co.uk>
Date: Tue, 20 Oct 2009 02:10:13 +0100
Message-ID: <4ADD0DF5.6040202@weborganics.co.uk>
To: "Tab Atkins Jr." <jackalmage@gmail.com>
CC: Philip J├Ągenstedt <philipj@opera.com>, Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>, Ian Hickson <ian@hixie.ch>, public-html@w3.org
Hello Tab....

Tab Atkins Jr. wrote:
> On Mon, Oct 19, 2009 at 7:13 AM, Martin McEvoy <martin@weborganics.co.uk> wrote:
>> You missed the point, How does my parser tell between attribute, is part of
>> a vocabulary defined at "itemtype" and which atribute is part of a custom
>> vocab made for just my use as useful script or css hooks?
>> My parser cant of course,  my parser would have to be re-built or modified
>> every time someone wants to define a new vocab.
> If it's a generic parser, it doesn't.  Generic parsers just grab all
> the data regardless.  Generic parsers don't *act* on the data, though
> - their only purpose is to scrape data which can then be fed to
> specialized programs which *do* understand particular vocabularies and
> can ignore pieces of data that don't exist in the vocab.
> If it's a vocab-specific parser (say, one that just looks for vcards)
> then it knows what the vocabulary looks like, and can ignore incorrect
> values up-front.

Thats what I said?

"My parser cant of course,  my parser would have to be re-built or modified
every time someone wants to define a new vocab."

thanks for taking the time to repeat that for me in depth ....

> So, if your parser is a generic parser, it never has to care about any
> particular vocabulary.  If it's a vocab-specific parser that actually
> knows the data model for certain vocabularies, then of course it will
> have to be modified if someone changes those vocabularies or you
> decide you want to start recognizing a new one.

Oops you were not finished, thanks for telling me things I already know  ;)

> I'm confused about your assertion about "attribute is part of a custom
> vocab made for just my use as useful script or css hooks", though.
> Microdata is *not* very useful as a script or CSS hook.  

I know it isn't,  what do you think Philip meant when he said this ...

"the microdata DOM API is useful in that it allows scripts to read and 
modify the data of a document with a relatively simple syntax. Otherwise 
you'd have to write many helper functions or wrapper objects to hide the 
underlying DOM tree."

sounds like he is talking about scripts reading and writing to the dom 
to me...I may be wrong though...
> Use classes,

Indeed, but you know what authors are like if there is a convenient hook 
there already why not use it. less markup .. less time..etc ...etc
> or if you must, data-* attributes.  Both of them are much easier for
> scripts and CSS to work with.  
Indeed ...

> If you expect to use Microdata for this
> purpose, then you're already somewhat off-track.
I don't ...

>> Microdata gets around all this by saying this....
>> "An item can only have one type. The type gives the context for the
>> properties."
>> http://dev.w3.org/html5/spec/Overview.html#typed-items
>> The above suggest that I can only define *one* vocab?  or does is? again not
>> very clear.
> I'm not sure what you mean, or how you are assuming this.  A
> particular item (that is, a blob of microdata contained in an HTML
> element with the @itemscope attribute), can only have a single type.

Thats what I said ...

"suggest that I can only define *one* vocab?"

or maybe I used the wrong word  instead of the word "vocab" I should 
have used the word "itemtype" sorry for confusing you  ....

> Another blob of microdata elsewhere on the page can have a different
> type.  

Ok again that's what I said
> Heck, a blob of microdata can contain itemprops which are,
> themselves, independent blobs of microdata with their own type.  For
> example, a book review vocabulary may have a "reviewer" property which
> is a vcard. 

Lovely ....
>  The overall book review would be one @itemscope with a
> particular @itemtype (the name of the book-review vocabulary), and it
> would have an @itemprop which is also an @itemscope with an @itemtype
> containing the name of the vcard vocabulary.

 Phew you said the same thing three times there Tab  :)

>> I will give you all some peace now, this conversation is too long and not
>> very easy to keep track of because of all the "round the houses" answers. I
>> dont like microdata, its an ugly syntax that doesn't answer any problems for
>> either the microformats community or the RDFa community. If browser vendors
>> want to Implement it, go ahead, I just think it a little premature, when you
>> could add some real value to your browsers implementing Microformats or RDFa
>> or both.
> Unfortunately, I continue to believe that you don't understand the
> microdata syntax at all, or how the overall system is supposed to work
> (it's almost identical to RDFa).  

If you say so but I don't know how... oh yes I do now ... Ian spent a 
month or two talking on the RDFa mailing list  finding out how RDFa 
works and then ....re-invented the wheel ... sorry "microdata RDFa but 

> Until you can demonstrate even a
> cursory understanding of the microdata data model or the microdata
> syntax, your contribution to any discussion around it is worth very
> little.

You are a funny man ;)

If you cant answer my questions properly why bother answering in the 
first place? you are wasting my time and yours.

Have you ever thought "Educate" instead of *insult*.

Martin McEvoy


"You may find it hard to swallow the notion that anything as large and apparently inanimate as the Earth is alive."
Dr. James Lovelock, The Ages of Gaia
Received on Tuesday, 20 October 2009 01:10:41 UTC

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