[Zope-PTK] FYI: Transitioning to ZPT

[Paul Everitt]

Howdy everybody.  I wanted to get everyone informed on a future 
direction for the CMF.  (Reminder to all: PTK is changing, at long last, 
to CMF, which means content management framework.)

Right now the skins use DTML snippets for all the pages in the site. 
The skins facility also gives the following:

   o Multiple installed skins

   o User selection between skins

   o Setting default skin for a site

   o Each page in a skin gets a common look and feel
     (from standard_html_header and standard_html_footer)

(Tres or Shane, does the skin facility allow any *logic* for the 
selection of a skin during a request, such as per-browser skins?  If the 
portal_skins folder exposed a Python Script for this...)

As mentioned, each page in a skin is written in DTML.  This will change 
after the 1.0 release, but perhaps in the next three months, to Zope 
Presentation Templates:

   http://dev.zope.org/Wikis/DevSite/Projects/ZPT/FrontPage

Here's the advantage from a CMF perspective.  With these kinds of 
templates, you don't have "snippets" of malformed, incomplete HTML. 
Instead, you have full-fledged XHTML pages that can be edited in many 
modern browsers.  (Dreamweaver 4 apparently hates XHTML, alas.)  You 
also get, though, central look and feel through the equivalent of 
standard_html_header and footer.

We at Digital Creations plan to move aggressively to this in our 
consulting practice.  Let me explain why and gather input.

Imagine you sit down with a prospective client that wants a CMS or 
portal.  Instead of sitting down with a blank whiteboard and saying, 
"What do you want?", you start with a working portal and complete use 
cases and ask, "How do you want to change it?"

With Adobe GoLive 5 (strong WebDAV and XHTML) driving a ZPT-based skin, 
you open up the entire demo portal -- *live*.  You start changing logos, 
rearranging elements such as the toolbox, changing colors, etc.  The 
elements, though mocked up in GL, still retain the dynamic instructions 
that allow them to work in Internet Explorer.

You also, though, start adding things that don't yet exist in the CMF. 
For instance, you add a box that has a poll on the front page and a link 
to poll results.  You represent this with dummy HTML that will be 
replaced by the ZPT when it is actually plugged into a component.

Thus, in real time, you are reskinning the site, retaining the existing 
dynamicism and putting in plugin-points for to-be-developed dynamicism. 
  In fact, you could probably run a catalog query and find all the <div> 
spots that haven't yet been finished -- that is, a to do list.

So that's a sneak peak of where we plan to take this over the coming 
months and why.

ZPT is getting a *ton* of energy behind it here.  Both Jim and Guido are 
contributing.  There's a release up now.  I imagine it will be 
architecturally stable in March and ready for production use in April. 
If it proves itself, it will be moved into Zope and DTML will be used 
much less extensively.  But we might put it into the CMF before it 
becomes a standard part of Zope.

We'll also encourage use outside of Zope.  In fact, we hope to see ports 
outside Python.  For instance, PHP, Java, etc.

--Paul