[Zope-dev] DocumentTemplate with a (bigger) brain

Tue, 14 Mar 2000 17:37:22 -0500

Hello all, I'm an old bobo fan who hasn't done much with the full zope.  
For the record I'd like to encourage y'all to keep things modular - 
everyone of us can benefit from parts of zope even if we can't - or 
aren't allowed - to use the whole thing.

Anyway, I've got a horrendously complicated site I'm working on with 
loads of really, really ugly javascript for things like fancy buttons, 
menus, &c.  The typical widget has an external javascript file, plus css 
on each individual page, and then a bunch of divs and images that are 
document.written on the client side when the page is loaded.  (Please 
don't flame if this is flawed, I'm not a Real Programmer [yet])

Thus you have three places where the page is affected by a widget:

<head>
     [script: external javascript file]
     [css definitions]
</head>
<body>
     [html defining widget]
</body>

I would like to define a widget object that can display itself through 
dtml, but I wonder if dtml is capable of such a thing.  When parsing a 
template, it would need to backtrack and insert additional css and/or a 
new external script tag at the top of the page.

Here's what I want as input:

<head>
     <title>check the fancy butts d00d!</title>
</head>
<body>
     <dtml-var super-cool-button>
</body>

And output:

<head>
     <title>check the fancy butts d00d!</title>
     <script src="fancybutt.js"></script>
     <style>
          #butt1 { position: etc }
     </style>
</head>
<body>
     <div id="butt1">
     etc
     </div>
</body>

Of course if there are two buttons on the page, this gets more 
complicated as each one will need to have unique names, and they will 
probably also have to be initializes onload.  Thus the tag needs to have 
1) some sort of memory, and 2) needs to be able to affect parts of the 
page outside the scope of the tag itself.

So - can this be implemented with DocumentTemplate, perhaps with a custom 
dtml tag?  Will it have to be done in two passes, or is there an idea for 
a better way?

Or even better, has anyone else come up with a nice widget implementation?