[Zope] Zope and Javascript

[Mark Gibson]

Passin, Tom wrote:
>>Behalf Of Asad Habib
>>
>>Does anyone know of any resources that describe the use of 
>>Javascript within Zope? In particular, I am trying to call a 
>>Javascript function using the onChange event handler that is 
>>tied to a HTML select element. I need this Javascript 
>>function to perform an SQL query and then have it populate 
>>another HTML select element with the result set. Is this 
>>possible within Zope considering that queries are performed 
>>by Z SQL methods and possible other factors that I am unaware 
>>of? Any help would be greatly appreciated. Thanks.
> 
> 
> A javascript function executed within a web page cannot influence
> anything that Zope does, because by the time that the javascript
> executes in the browser, Zope has alread finished producing the page.
> The javascript action is local to the browser.
> 
> How you do it is to have your onChange handler submit a form to Zope.
> That form should invoke a document, methods, etc., on Zope that will
> construct the response you want (including any database access), and
> return it to the browser.

Another thing you can do is generate the javascript dynamically with a 
python script.  You'd have to do all possible queries before 
displaying the form, and from that create the necessary javascript. 
This would be too inefficient for a large set of data, but might be 
workable for a small set.  Actually, Tom's solution sounds better for 
this particular problem.

Mark