[XML-SIG] Useless fun thing for XML - comments or helpers?

[Sean Mc Grath]

Mark,
A couple of things.

1) XML is case sensitive. How about lowercase or CamelCase for the element
type names.?

2) The characters "<" and "&" are special in XML and must be escaped if they
occur as part of the content (in URL's for example you can have "&").
This does not effect your DTD, but needs to be born in mind when generating
XBEL files. "&" -> "&amp;". "<" -> "&lt;"

3) In XML there are no standard ways of specifying lexical structure in
PCDATA (yet). Attributes give better (but still unsatisfactory) control.
I am thinking primarily of the date element type.

<date yyyy = "2005" mm = "12" dd = "01"/>

is more checkable than

        <date>2005/12/01</date>

4) There are many, many ways to go from XBEL to HTML and other formats:-

  DSSSL Stylesheet (James Clark's Jade)
  XSL StyleSheet (James Clark's XT via JPython)
  Custom Python Translator
  ...

5) There is a lot of stuff going on in XML at the moment that will all
impact on XBEL as it develops:-

 a) Rendering via XSL
 b) Hypertext linking via XLink
 c) Namespaces (making the vocabulary of XBEL formally public and documented
via a DTD)
 d) DCD - A proposal for a more powerful schema language for XML than DTDs

I suggest we keep it all very simple for now! Even as it stands a tool like
sgrep - structured grepping - really shows up the advantage of XBEL.


[Mark Hammond]
><!-- DTD for XBEL - XML Bookmark Exchange Language -->
>
><!ELEMENT XBEL     (INFO, NODE+)>
><!ELEMENT NODE     (NAME, BOOKMARK+)>
>
><!ELEMENT BOOKMARK (NAME, URL)>
>
><!ELEMENT INFO     (OWNER, MACHINE, VERSION, DATE?)>
>
><!ELEMENT OWNER    (#PCDATA)>
><!ELEMENT MACHINE  (#PCDATA)>
><!ELEMENT VERSION  (#PCDATA)>
><!ELEMENT DATE     (#PCDATA)>
>
>
><!ELEMENT NAME     (#PCDATA)>
><!ELEMENT URL      (#PCDATA)>
>
>
</Sean>

Sean Mc Grath - http://www.digitome.com/sean.htm
XML by Example:Building E-Commerce Applications 
	(http://www.amazon.com/exec/obidos/ISBN=0139601627/digitomeelectronA/)
ParseMe.1st - SGML for Software Developers
	(http://www.amazon.com/exec/obidos/ISBN=0134889673/digitomeelectronA/)