[Zope-dev] Using Java-Script with DTML

[Hung Jung Lu]

--- In zope@egroups.com, Thomas Weholt <Thomas@c...> wrote:
><script language="javascript1.2>
>
>function ShowStuff(params){
>
>	var text = "<dtml-in expr="sqlMethod(some_id=params>" <!-- this does
>not work, of course. How I can I pass argument thru Javascript to the
>sqlMethod ?? --->
>	alert (text);
>}
>
></script>

I think I know what you are talking about. But you have to really
keep your mind straight about one thing: DTML runs with the CPU
on the server side, JavaScript runs with the CPU on the client side.
In other words, by the time you are running Javascript, you
CAN'T access your database records.

I have done a lot of things in displaying dynamic pull-down menus.
E.g: you choose a state from one pull down menu, and the content
of another pulldown menu is automatically changed to the list of
cities within that particular state. When you click on a state,
you CAN'T query your database for the list of its cities. It's
too late, your code is already running on the client side. So
what should you do? What you should do is to pre-generate
JavaScript arrays, storing the names of all the cities for all
the states.

That being said, there is one more caveat. When you pre-render
your database records into JavaScript arrays, you have to be
careful about quoting. I don't know whether there are any string
format quoting in DTML suitable for rendering into JavaScript
(the <dtml-sqltest ... type=string> comes to mind, but I am not
sure it works outside ZSQL methods), I ended up implementing my
own external method to quote Python strings into JavaScript strings.

If you still don't understand what I mean, consider a python string

    'He said, "no".'

stored in your DTML variable mystring, that is, something like:

    <dtml-call "REQUEST.set('mystring', 'He said, "no".')">

and you pre-render it into JavaScript code

    x = "<dtml-var mystring>";

It won't work. Because if you look at the source of your JavaScript,
you will see:

    x = "He said, "no".";

regards,

Hung Jung

________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com