XOM API for Processing XML with Java

[Elliotte Rusty Harold <elharo AT metalab.unc.edu>]

At 1:54 PM -0700 9/29/02, O'Brien-Strain, Eamonn wrote:

> Sparta does handle some well-formedness checks, like making sure 
> that elements names have correct characters.  However, because 
> Sparta does not validate DTDs and is designed to be as fast and 
> small as possible, it ignores everything it can in the <!DOCTYPE 
> ...> section and so there are bound to be some well-formedness 
> checks that it fails -- but these should not effect the DOM tree.

I was afraid of this. XMLPULL has the same problem. Well-formedness 
checks on the document entity are not optional. If Sparta isn't doing 
them, then Sparta is not an XML processor as defined by XML 1.0. From 
section 5.1 of the spec:

Validating and non-validating processors alike must report violations 
of this specification's well-formedness constraints in the content of 
the document entity and any other parsed entities that they read.
...
Non-validating processors are required to check only the document 
entity, including the entire internal DTD subset, for 
well-formedness. [Definition: While they are not required to check 
the document for validity, they are required to process all the 
declarations they read in the internal DTD subset and in any 
parameter entity that they read, up to the first reference to a 
parameter entity that they do not read; that is to say, they must use 
the information in those declarations to normalize attribute values, 
include the replacement text of internal entities, and supply default 
attribute values.] Except when standalone="yes", they must not 
process entity declarations or attribute-list declarations 
encountered after a reference to a parameter entity that is not read, 
since the entity may have contained overriding declarations.

Given Sparta's failure to satisfy this requirement, the comparisons 
on its web page to Xerces are unfair.  Gaining speed by not 
performing the mandated well-formedness checks is cheating. More 
importantly, it's extremely damaging to the XML ecosystem. The one 
thing that's guaranteed in XML is well-formedness. It is the 
foundation on which everything else rests. If you're letting 
malformed XML through your parser, then you're polluting the XML 
ecosystem. I can't recommend that anybody use a parser that 
deliberately chooses not to check for well-formedness. In fact, I 
actively recommend that they don't.
--

+-----------------------+------------------------+-------------------+
| Elliotte Rusty Harold | elharo AT metalab.unc.edu | Writer/Programmer |
+-----------------------+------------------------+-------------------+
|          XML in a  Nutshell, 2nd Edition (O'Reilly, 2002)          |
|              http://www.cafeconleche.org/books/xian2/              |
|  http://www.amazon.com/exec/obidos/ISBN%3D0596002920/cafeaulaitA/  |
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