Vadim Gritsenko <[EMAIL PROTECTED]> wrote on 06.06.2005 16:28:19:
> > I think it is a bad idea to use exactly the same syntax as for
> XSLT because it
> > makes really awkward to use XSP attribute interpolation inside
logicsheets.
>
> You haven't written any XSLT producing Ant files recently, have you? :-)
> Now it seems really easy to me, you simply write:
>
> <img src="{{foo}}"/>
>
> in the XSLT.
I have submitted a first patch for XSP expressions [1]. See the patch
description what is implemented right now (the parser is easily
replaceable :).
The patch uses "{#" and "}" because IMO it best suits the requirements:
1. The parser shouldn't need to know about the programming language.
2. Unlikely occurrence in existing XSPs
3. Unlikely occurrence in implemented programming languages (I think it's
only perl with "$#array" or something).
4. Code is movable between XSPs and logic sheets.
5. Minimum interference with XSLT syntax. Logicsheets already contain lots
of "{var}" and "{{quotedText}}".
>
>
> > You end up wasting your time figuring out which curly mountain is
needed to
> > get the expression to be interpreted by the right engine.
> >
> > It should be easy for both humans and the XSP processor to
> distinguish between
> > XSP and XSLT expressions.
>
> I don't get your point about XSP processor. It is already dead easy for
it.
We probably would have to write "{{{{quotedText}}}}". The logic sheet
expression filter reduces this to "{{quotedText}}" and the XSLT processor
then to "{quotedText}".
>
>
> > I don't know AxKit in detail but I assume that them using "{foo}"
> syntax means
> > that they are not using XSLT-based logicsheets.
>
> It's implemented in PERL, for logicsheets they have .pm files, iirc.
>
>
> > Anyway, we can still claim to
> > use a common standard by defining:
> >
> > interpolated-expr ::= '{' language-expr '}'
> > language-expr ::= perl-expr | '?' java-expr | '?' javascript-
> expr | '?' python-expr
>
> Extra character does not add any elegance, imho.
>
>
> >>As for backward compatibility, is is already solved by:
> >>
> >> <xsp:page attribute-value-interpolation="no">
> >
> >
> > But the default value should be attribute-value-
> interpolation="yes", provided
> > we can agree on a syntax which is highly unlikely to be used in
> existing XSPs.
>
> If default is "yes" by default :-) then you'll break all the
installations of
> Cocoon out there in one shot. *Not* nice!
>
> Hence, default must be at least configurable - in the cocoon.xconf.
It is.
>
> Vadim
Regards,
Jochen
[1] http://issues.apache.org/bugzilla/show_bug.cgi?id=35228
