Re: [xml-dev] Processor treatment of entities

["G. Ken Holman" <gkholman@CraneSoftwrights.com>]

At 2005-04-12 02:31 -0500, Jack Matheson wrote:
>In section 4.4 of the XML specification, a distinction is made between 
>entities referenced in attribute values

<bar acronym="AT&amp;T"/>

>and entities occurring as attribute values.

<!NOTATION gif SYSTEM "">
<!ENTITY foo SYSTEM "../../images/foo.gif" NDATA gif>
....
<figure image="foo"/>

>Can anyone explain this difference to me?

I hope the above distinction helps.  Unparsed entities can only be 
referenced as attribute values ... since they aren't parsed, they cannot be 
referenced as a parsed entity as in &foo;.

An unparsed entity's relative URI is resolved to an absolute URI based on 
the location of the entity declaration in either the internal or an 
external declaration subset.  In XSLT using unparsed-entity-uri() will get 
you the absolute URI.  This is very helpful in publishing when managing the 
locations of graphic files being referenced for XSL-FO engines.

I don't see many of my students having used unparsed entities, though, when 
I cover this topic in class.

I hope this helps.

........................... Ken

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