RE: Bug in Apache::ASP XMLSubs when an argument includes '>'-char acte rs?

[Henrik Tougaard <ht...@foa.dk>]

> From: Matt Sergeant [mailto:matt@sergeant.org]
> On Fri, 11 Aug 2000, Henrik Tougaard wrote:
> > With this simple .asp page I get an error:
> > 
> >     <Fiks:test Start="<b>"> </Fiks:test>
> > [My XMLSubMatch is set to Fiks:\w+  - the name of the 
> subroutine doesn't
> > matter]
> > 
> > It seems as if the '>' in the '<b>' argument confuses the parser.
> 
> [snip]
> 
> > Is this a (mis)feature or a parser bug?
> 
> parser bug - it should have died earlier at the < sign :-)
> 
> XML attributes can't contain "<" or "&" characters, or the 
> same quote that
> they are surrounded by. The following are the encodings you can use
> (and XMLSubsMatch needs to unravel):
> 
> <   =>  "&lt;"
> >   =>  "&gt;"
> &   =>  "&amp;"
> "   =>  "&quot;"
> '   =>  "&apos;"
> 
> Note that only "<" is needed for your example (since encoding the
> ">" isn't mandatory in XML generally).
> 
Well this does limit the usefullness of the XMLSubs feature.
I had hoped that it would be possbile to use any perl expression in
the attributes - as an easy way of giving arguments to the perl-sub.

Pity....

--
Henrik

Re: Bug in Apache::ASP XMLSubs when an argument includes '>'-characte rs?

[Joshua Chamas <jo...@chamas.com>]

Henrik Tougaard wrote:
> 
> > XML attributes can't contain "<" or "&" characters, or the
> > same quote that
> > they are surrounded by. The following are the encodings you can use
> > (and XMLSubsMatch needs to unravel):
> >
> > <   =>  "&lt;"
> > >   =>  "&gt;"
> > &   =>  "&amp;"
> > "   =>  "&quot;"
> > '   =>  "&apos;"
> >
> > Note that only "<" is needed for your example (since encoding the
> > ">" isn't mandatory in XML generally).
> >
> Well this does limit the usefullness of the XMLSubs feature.
> I had hoped that it would be possbile to use any perl expression in
> the attributes - as an easy way of giving arguments to the perl-sub.
> 

I think > is just about the only thing that you can't use as
a character in the attributes for an XMLSubs and that's because
it gets parsed with an aggressive ( or stupid ;) regexp like:

	$$data =~ s|\<\s*($self->{xml_subs_match})([^\>]*)/\>

So basically what its doing is looking for everything up
to the first > so to put that in the data pretty well kills
it.  The arguments are further evaluated from there as $2.
Its simple and fast, and would be really good to keep it 
this way.  

Note that XMLSubs attributes can be most valid perl expressions,
but I don't think > could be supported in this context either.

Another related XMLSubs attribute issue came up recently
where it was hard to quote the @ character because in perl
"some@email" will error usually, and the quick fix for this
is to have an argument with single quotes like email='some@email'

Internally an XMLSubs attribute will go from 
  <my:tag email='some@email' range=10 />
to something like
  &my::tag(email => 'some@email', range => 10)

-- Joshua

_________________________________________________________________
Joshua Chamas			        Chamas Enterprises Inc.
NodeWorks >> free web link monitoring	Huntington Beach, CA  USA 
http://www.nodeworks.com                1-714-625-4051

RE: Bug in Apache::ASP XMLSubs when an argument includes '>'-char acte rs?

[Matt Sergeant <ma...@sergeant.org>]

On Tue, 15 Aug 2000, Henrik Tougaard wrote:

> > XML attributes can't contain "<" or "&" characters, or the 
> > same quote that
> > they are surrounded by. The following are the encodings you can use
> > (and XMLSubsMatch needs to unravel):
> > 
> > <   =>  "&lt;"
> > >   =>  "&gt;"
> > &   =>  "&amp;"
> > "   =>  "&quot;"
> > '   =>  "&apos;"
> > 
> > Note that only "<" is needed for your example (since encoding the
> > ">" isn't mandatory in XML generally).
> > 
> Well this does limit the usefullness of the XMLSubs feature.
> I had hoped that it would be possbile to use any perl expression in
> the attributes - as an easy way of giving arguments to the perl-sub.

Note that I'm speaking not from Apache::ASP's point of view, but from an
XML point of view. I don't know if Joshua wants to work around these rules
- I certainly never saw a necessity of encoding "<" in an attribute
value. Its not like its really difficult to parse without it. In fact its
_more_ overhead to do it the way the XML spec specifies...

-- 
<Matt/>

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