[DAS2] properties

[Thomas Down]

On 23 Jan 2006, at 13:34, Andrew Dalke wrote:

> Thomas wrote:
>
>> This seems to be inventing a new namespace-management mechanism.   
>> I'm always a bit nervous about schemes which require someone to  
>> maintain a registry of namespaces.  Was there really a problem  
>> with the old system of using the XML document's namespace map to  
>> scope property names?
>
> I don't have a good feeling about any solution to this.  It comes
> down to what people will be using these property tables for.
>
> Are they only meant for machines?  For people?  For both?

I've been seeing this very much as something for machines.  You don't  
want to be showing end-users your stylesheet data, at least not in  
XML format -- although smarter clients might want to have a dedicated  
stylesheet editor, of course.

The current examples in das2_get.html imply that there is a special  
type of property for "notes" (i.e. chunks of text you want to show  
the user):

              <PROP ptype  = "das:note">This is a telomeric repeat</ 
PROP>

I'd taken this to imply that other types of property were generally  
*not* meant to be shown directly to the user, except in "special"  
ways by clients that understand their semantics.   But I guess there  
are cases where you want to show "tag-value" type data to the end  
user (I'm thinking here about adding extra rows to tables like the  
ones you see on http://www.ensembl.org/Drosophila_melanogaster/ 
geneview?gene=CG11015).  I think there's an argument for handling  
this a bit differently, for example:

              <das:note caption="Repeat family details">This is a  
telomeric repeat</das:note>

(This kind of solution appears to drop in pretty nicely if we allow  
arbitrary XML "extension elements").

          Thomas.