[Zope3-dev] Re: XML header and TAL interpretor

Thu Sep 1 08:33:19 EDT 2005

Derrick Hudson wrote:
> On Wed, Aug 31, 2005 at 03:54:45PM +0200, Philipp von Weitershausen wrote:
> | Julien Anguenot wrote:
> [...]
> 
> | > If you change the header like this then it can be succesfully included :
> | > 
> | > <?xml version="1.0" encoding="UTF-8"?>
> | > <html xmlns="http://www.w3.org/1999/xhtml"
> | >       xmlns:tal="http://xml.zope.org/namespaces/tal"
> | >       xmlns:metal="http://xml.zope.org/namespaces/metal"
> | >       xmlns:i18n="http://xml.zope.org/namespaces/i18n"
> | >       i18n:domain="zope">
> | > <body>
> | > 
> | > What kind of issue could we have changing the headers like this on all
> | > the standard macros since it's xhtml already ?
> | 
> | I'm not sure if this is a good idea. Because once Zope3's macros are XML
> | mode, all other templates using those macros need to be XML mode. That,
> | in turn, means that all templates need to carry the <?xml ...?>
> | processing instruction because that's the only way XML mode is currently
> | triggered. Since that processing instruction is optional (as opposed to
> | namespace declarations which are mandatory), I wouldn't want to force it
> | on template authors.
> 
> Don't forget that IE will then have an insane tendency to render the
> pages wrong.  I don't recall all of the details, but it was something
> like if the document began with <?xml ?> IE would switch to "quirks
> mode" and do funny things with boxes, margins, and the overall layout.
> The details are in this list's archives (if they aren't it's in the
> zope at zope.org list archives).

I know about quirks mode and how it's provoked with <?xml ... ?>.
Exactly because of that it has been impossible to use ZPT's XML mode to
render web pages -- because IE will choke on the <?xml ... ?> that is
necessary to put the ZPT machinery into XML in the first place... a
vicious circle so to speak.

If we make XML the default mode, I don't see how it would impact IE very
much. After all, the <?xml ... ?> processing instruction would then be
optional and could be left out for XHTML pages. It would finally be
possible to properly embed XForms, SVG etc. into XHTML though.

Philipp