[Zope] Re: Is DTML a bastardized form of XML, or valid XML?

[Paul Everitt]

There was tremendous discussion on the mailing list around the time of
the introduction of the new syntax.  As Jim made clear, the goals of the
new syntax did _not_ include XML compliance.  Instead, the goals were:

a. Get rid of the old syntax.  The SSI style was universally ridiculed
and requires typing of hard-to-reach characters.

b. Make it possible for some HTML editors that can extend their tag
database to recognize DTML tags.

At the time of the introduction, XML editors were not widely adopted.
That still hasn't changed.

Hope this correction helps.

--Paul

> -----Original Message-----
> From: Joe Pallas [mailto:pallas@cs.stanford.edu]
> Sent: Friday, June 23, 2000 8:39 AM
> To: Martijn Pieters; Hung Jung Lu
> Cc: khowe@performance-net.com; zope@zope.org; info@digicool.com
> Subject: Re: [Zope] Re: Is DTML a bastardized form of XML, or 
> valid XML?
> 
> 
> I'm pretty sure "new syntax" DTML is not actually valid XML, but it 
> doesn't really matter:  it's a bad idea either way.  The new syntax 
> is a misguided attempt to mix the base and meta levels, which can 
> only result in confusion.
> 
> DTML is not markup, it is a macro language for generating markup.  As 
> such, it will not always be possible to coerce it into a form that 
> meets the syntax rules of the base language.  But meeting those 
> rules, and consequently being able to use XML editors, is the only 
> real justification for the new syntax.
> 
> <h1 <!--#if "fervor > 2"-->class="hot"<!--#/if-->>
> How do I do this in "new" DTML?
> </h1>
> 
> <h1 <dtml-if "fervor > 2">class="hot"</dtml-if>>
> This isn't valid XML (bad attribute).
> </h1>
> 
> <dtml-if expr="fervor > 2">
> <h1 class="hot">
> <dtml-else>
> <h1>
> </dtml-if>
> This isn't valid XML, either (bad nesting).
> </h1>
> 
> <dtml-if expr="fervor > 2">
> <h1 class="hot">
> This is very clumsy and does not scale.
> </h1>
> <dtml-else>
> <h1>
> ...but I think it is valid XML.
> </h1>
> </dtml-if>
> 
> Also, XML requires all attributes to be quoted, so forget about using 
> the implicit name/expr distinction with your shiny new XML editor.
> 
> The new syntax doesn't satisfy the arguments that were given to 
> support it, and it decreases the readability and maintainability of 
> DTML code that uses it by making it hard to distinguish DTML 
> directives from markup.  I avoid it, and I don't recommend it to 
> others.
> 
> joe
>