[Zope] AJAX and Zope

Wed May 24 10:41:18 EDT 2006

Lennart Regebro wrote:
> On 5/24/06, Pascal Peregrina <Pperegrina at lastminute.com> wrote:
>> By Zope objects I meant:
>>
>> You've got a page template for example, and you include such an "AJAX 
>> enabled object", basically rendering an HTML fragment, and the 
>> resulting page will include the page template code + the fragment 
>> (similar to a macro call), but will also include the needed 
>> javascript code to handle the asynchronous communication.
>
> That is a macro call. There is no difference. It just that the macro
> includes the HTML needed to suck in the JS library you use.
I have been working on a simple WSGI middleware filter that handles js 
library insertion pretty well, without complicated macros that assure 
that a javascript library gets included only once. 

It works by creating a WSGI environ variable for desired includes.  
Individual widgets ask a utility to register their need for a particular 
javascript or css resource into that environ variable.

After Zope is finished generating the page, the middleware inserts the 
appropriate <script> and/or <style> tags into <head> before delivery to 
the client.

The current implementation works in Zope 3.  I have not experimented 
with Zope 2 on this, but it seems that with Zope 2's new 
WSGI-friendliness and Five, it is likely not too far from something 
usable in Zope 2.  The Zope 3 implementation needs zope.paste and 
paste.deploy.  The middleware app itself should work for anything WSGI.

Code (Due credit: the Zope 3 infrastructure for this borrows heavily 
from zc.resourcelibrary) and instructions are at 
http://zif.hill-street.net/headincludes  Development status: "works for me".

This is just a small piece of the AJAX puzzle for Zope, as I see it.

-Jim Washington