Binary Data

Rick Jelliffe ricko at allette.com.au
Mon Feb 23 17:22:52 GMT 1998


From: Michael Emmel <mike at jmaca.com>

>This says to me that binary data is required to either be encoded to ascii
to
>be included, or have Mime type boundries for XML tags with  binary data
> not containing the mime boundries included.
>In the document or be obtained from a ascii normalized external URI link.


Binary data can only be included in a parseable entity if it is first
encoded
in some way which
1) does not contain delimiters which may cause false triggering
2) does not contain any characters which the XML "SGML declaration"
says are unused (or shunned).
Base64 is one such encoding. Other encodings may be more efficient
if you have a 16-bit data stream.

The way to signal you are using an encoding is to use an element
with a notation attribute.

If you embed binary data with MIME type boundaries, you no longer
have a parseable XML entity, you have a MIME multipart file which
can be processed to generate an XML entity.

>There is no way to tell a XML arser to skip x number of  arbitrary bytes of
>embedded unparsed entity  data which is consumed by the "application"  and
then
>restart the parser
>at the next valid section.

An XML parser is not interested in the contents of a non-XML-parseable
entity. Indexing into binary data is either done before the parser (i.e. by
embedding the appropriate instructions in the system identifier of the
entity) or by the application after the parser.

>Am I wrong ???


What do you mean "restart the parser"?  Parsing continues after an entity
reference.

Rick Jelliffe


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