I just wanted to share some experiences with Modular XHTML and XML tools.
We developed according to the rules specified in the W3C recommendation of 10th april 2001 "Modularization of XHTML" an XHTML Host Language Document Type leaving out some XHTML modules and including SVG and MathML.
We wondered how different XML tools could handle this DTD in which parameter entities and conditional sections are heavily used.
Schema and DTD editors.
a) Near & Far designer from Open Text
works if you do comment out some entities defined in MathML for inserting special characters that fall within a certain Unicode range.
b) XML Spy from Altova
does NOT work. Shokes on parameter entities having an empty content, example:
<!ENTITY % xhtml-xlink.mod "" >
%xhtml-xlink.mod;
c) XML Authority from TIBCO
does NOT work.
java.lang.NullpointerException
XML editors
a) XML Spy from Altova
NOT. cf. supra
b) XML Instance from TIBCO
NOT. cf. supra
c) XML Pro from Vervet Logic
Works.
d) XMetal from Softquad
Works.
e) Epic from ArborText
Works except for that you CANNOT use the internal subset for putting on/off namespace prefixes and changing the prefix itself, which is an explicite requirement of modular XHTML.
Parsers
a) Xalan-C
Works.
b) Microsoft MSXML 4.0
Doesn't give error messages concerning the DTD, but gives a very strange error message concerning a test document itself:
"A name was started with an invalid character. Line 1, Position 2
&<"
while the document starts with <html>.
????
Conclusion: XML 1.0 + namespaces isn't simple. Even after almost 4 years, a lot of tool vendors cannot handle more complex DTD's.
Don't argue that DTD's don't matter anymore. For modular XHTML no schema framework is in place yet and I'm very curious about the proposition w3c will come up with.
Regards,
Paul
Pro Text
Paul Hermans
Leuvensesteenweg 282/c
3190 Boortmeerbeek (Belgium)
+32 15 61 85 45
+32 15 62 03 99 (fax)
Paul_Hermans@protext.be