Re: PROPOSAL to close ISSUE-40: no triples for empty elements

Richard Cyganiak wrote:
> On 5 Sep 2010, at 20:18, Nathan wrote:
>> this:
>>
>>  <span property="foo:bar">{$templatevar}</span>
>>
>> is just as likely as this:
>>
>>  <span property="foo:bar" content="{$templatevar}" ...
> 
> No, they are not equally likely. The second is for the case where the 
> user-visible string has to be different from the machine-visible string. 
> That is not the common case. Also, less sophisticated authors are much 
> more likely to use the first pattern, and they are the ones we need to 
> worry about here -- the ones who are likely to forget about zero-length 
> literals and similar corner cases.

agree, but only for the time being, @content could easily become defacto 
over the next 1-2 years (if not sooner). IMHO this is more of 'move the 
problem somewhere else' rather than a fix.

> But given that @content="" can also occur accidentally, if you have 
> another idea how to express the empty string in a way that is less 
> likely to be authored by accident...?

only two things I can think of is a token/keyword to represent no 
content, or adding an optional @content-length attribute which you could 
set to 0 to complement the empty "", the former being preference but, 
still not ideal.

>> generally it's going to be programmers who write the scripts that 
>> consume / process RDFa and if they feel like adding a line that throws 
>> away all triples with empty elements then it's hardly a big job.
> 
> I don't like this attitude. As a consumer of RDFa data I shouldn't have 
> to guess wether the RDFa author meant to have that zero-length string or 
> wether they just didn't know what they were doing.

fair point and agreed.

>> note:
>> I'd hope that we'll all be moving to including datatype restrictions 
>> in ontologies in the near future which will cover whether a given 
>> value is valid for a given property or not, perhaps this along with 
>> processors which understand restrictions is the long-term-fix that 
>> addresses this and similar issues.
> 
> Well I agree, but that's at best a long-term hope and not something that 
> can be addressed now in RDFa.

aye, shame.

Hope you're well,

Nathan

Received on Sunday, 5 September 2010 22:54:19 UTC