Re: Embedding RDF metadata within an XML document

[John Cowan <jcowan@reutershealth.com>]

Warren Hedley wrote:


> 2. If we are embedding the metadata inside the resource to
> which it refers, is it appropriate to omit the @about attribute
> on the <rdf:Description> element?
> Does omitting the @about attribute imply that the RDF block
> refers to the resource in which it is contained? (This is the
> behaviour that we are after.)

Just to be definite: No, it doesn't. Omitting the about
attribute gives you metadata that is about a newly created
anonymous resource.

The empty-string URI reference always refers to the current
document, so you can (as another poster has said) use about=""
to make clear that your metadata describes the document
in which it is embedded.

However, based on your example below, you are in fact
using metadata to describe only *part* of the document
in which it is embedded, specifically the element in which
the metadata is embedded.  If that is your intent, then
you must change your example to something like this:

> <cellml:some_cellml_element id="some">
> 
>   <rdf:Description about="#some">
>     <cmeta:some_metadata_element>
>       Some metadata content
>     </cmeta:some_metadata_element>
>   </rdf:Description>
> 
>   Some CellML content
> 
> </cellml:some_cellml_element>
> 
> <cellml:another_cellml_element id="another">
> 
>   <rdf:Description about="#another">
>     <cmeta:some_metadata_element>
>       Different metadata content
>     </cmeta:some_metadata_element>
>   </rdf:Description>
> 
>   Some CellML content
> 
> </cellml:another_cellml_element>
> 
> Is this correct use of RDF? Are processors likely to be able to
> make use of it? Are processors going to be able to determine
> which metadata applies to <some_cellml_element> and which
> applies to <another_cellml_element>?

The id attributes in the CellML elements (where you must
declare the id attribute as of type ID in your DTD) match
up with the URI references in the about attributes in the
rdf:Description elements.  (Note that the URI references
must begin with "#" and the ids must not.)


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