SAX: problem areas (was Re: SAX: Whitespace Handling)

David Megginson ak117 at
Sun Jan 4 15:15:44 GMT 1998

Peter Murray-Rust writes:

 > I also take it as almost axiomatic that SAX should support everything in
 > the spec *relevant to those areas it addresses*.  IOW if it doesn't support
 > NOTATION it could ignore everything to do with that (e.g. NDATA.
 > NotationType) and might simply throw an Exception (SAX ignores NOTATION -
 > or whatever). [I am not making  any judgment on NOTATION - but it is
 > possibly not a core component].

I suggest that parsers using SAX should be more than welcome to
provide their own mechanisms for communicating information about
notations -- they are simply not part of the SAX information set.  For
example, I might have this in the DTD:

  <!NOTATION video SYSTEM "">
  <!ENTITY clip SYSTEM "video-clip.vid" NDATA video>

  <!ELEMENT video-ptr EMPTY>
  <!ATTLIST video-ptr
    object ENTITY #REQUIRED>

and this in the document

  <video-ptr object="clip"/>

SAX will simply report that the attribute "object" has the value
"clip", without worrying that there is a notation called "video";
however, Ælfred, for example, will let you look up the type of
"object", find out that it's an entity, look up the associated
notation, and then get the notation's system identifier.

All the best,


David Megginson                 ak117 at
Microstar Software Ltd.         dmeggins at

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