ssax-sxml

[ssax-sxml] Bug in ssax:xml->sxml

[Lindsay S. <li...@co...>]

I am trying to define my own namespace definitions before parsing an xml 
fragment.  It does not work.

Example:

#;> (define testxml "<foo><testns:tag>bar</testns:tag></foo>")

#;> (call-with-input-string testxml (lambda (port) (ssax:xml->sxml port 
'((testns . "replaced")))))
Error: [nsc-NSDeclared] broken; prefix

Possible solution:

inside ssax:xml->sxml :

(namespaces
    (map (lambda (el)
           (cons* #f (car el) (ssax:uri-string->symbol (cdr el))))
         namespace-prefix-assig))

This appears to incorrectly set up the namespace list for the 
user-supplied namespaces.  The #f on the front makes the assq call in  
ssax:resolve-name fail.

If I change it to:

(namespaces
    (map (lambda (el)
           (cons* (car el) (ssax:uri-string->symbol (cdr el)) #f))
         namespace-prefix-assig))

Then I get:

#;> (call-with-input-string testxml (lambda (port) (ssax:xml->sxml port 
'((testns . "replaced")))))
(*top* (|@@| (*namespaces* (testns "replaced")))
       (foo (replaced:tag "bar")))

which is the desired result. I don't really know if the #f belongs on 
the end of the association list, but I know from reading resolve-name 
that the cadr must be the thing to replace it with.

This has also been filed as a bug on sourceforge.

Lindsay

Re: [ssax-sxml] Bug in ssax:xml->sxml

[<ol...@po...>]

Hello!

> I am trying to define my own namespace definitions before parsing an xml 
> fragment.  It does not work.

There is no bug in the SSAX code, but there is a matter of
misunderstanding.

	<foo><testns:tag>bar</testns:tag></foo>

That is not well-formed XML (if we take XML Namespace Recommendation
into account): the namespace `testns' is not defined. So, SSAX
correctly reports the error, *as it must* according to that
Recommendation.

The well-formed document would look like


  <foo xmlns:testns="http://my/long/URI"><testns:tag>bar</testns:tag></foo>

When you parse it, you'd get
  (*TOP* (foo (http://my/long/URI:tag "bar")))

obviously, tag `http://my/long/URI:tag' is a bit too unwieldy to carry
around. That's where user-defined prefixes come in:

gosh> (call-with-input-string testxml 
       (lambda (port) (ssax:xml->sxml port '((t . "http://my/long/URI")))))
(*TOP* (|@@| (*NAMESPACES* (t "http://my/long/URI"))) (foo (t:tag "bar")))

So, you define the abbreviation 't' that stands for http://my/long/URI
as the namespace URI. The prefix `testns' doesn't occur anywhere -- as
it actually shouldn't by the intention of XML Namespace
Recommendation. The prefix `testns' can still be preserved in the
output of the parser (as some XML activities are alas contrary to the
spirit of XML Namespace Recommendation).

The Section
	http://pobox.com/~oleg/ftp/Scheme/SXML.html#Namespaces

discusses this subject of XML Namespaces and prefixes in more detail.

	Cheers,
	Oleg