XML Spaghetti (Was Re: XML spec dependencies chart --)

[AndrewWatt2000@aol.com]

In a message dated 15/04/01 20:47:18 GMT Daylight Time, 
igraham@ic-unix.ic.utoronto.ca writes:


> As part of a lecture, I prepared a slide showing the dependencies of the
> various W3C XML specs (plus SAX), and I thought this might be of interest
> to some on this list. A screen capture of the PPT slide is found at:
>
> http://www.java.utoronto.ca/~igraham/xml-depend.gif
>
> The arrows indicate which specs a given spec depends on (dependencies
> being accumulative). Orange corresponds to a 'recommendataion', and blue
> to a working draft or a 'proposed recommendataion'. There are no
> specification versions .... 
>
> I hope to eventually turn this into an animated slide ... could have the
> various spec's pop into appearance according to the historical timelines.
> I suspect that the growth is at least exponential .....


Ian,

A short time ago Simon St Laurent posted on list regarding a fork in the XML 
road. Your diagram confirms my suspicion that the fork is covered in XML 
Spaghetti.

What I am about to say is not a criticism of the diagram, I simply wish to 
point out that the diagram in my view seriously underestimates the complexity 
of the relationships.

It is incomplete, in the sense that XML Encryption, XMLP/SOAP, VoiceXML etc 
are not mentioned. I appreciate that it could be argued that these are at too 
early a stage to merit inclusion. But who can doubt that they are coming?

Dependencies for individual technologies are also oversimplified. For 
example, SVG has dependencies on the XML Stylesheets rec, XLink, XPointer 
(parts), SMIL 1.0, SMIL Animation, SMIL 2.0, DOM Level 1, DOM Level 2, CSS2. 
I am not sure if that is exhaustive but it gives an idea of the problem from 
the user point of view. Those dependencies are not shown.

Not to mention the impending cloying dependencies of many specs on W3C XML 
Schema! I understand that those are not yet imposed but when they are that 
too will add significantly to the complexity.

What happens in a year or two? Again taking SVG as a possible example, what 
will happen with a (as yet hypothetical) SVG 2.0 spec? How will it relate to 
the 18 modules of CSS3, the modules of DOM Level 3 and a whole host of other 
specs? Which ones will it relate to? How does a user find their way to 
untangle the XML spaghetti?

If XML was designed to be "simple", or at least simpler than SGML, how is 
that we have arrived so soon at this XML Spaghetti? If your perception of 
exponential growth is correct, and I suspect it is, the tangle of XML 
Spaghetti can only become more daunting with time.

Andrew Watt