dynamic generation of pulldowns

New Member Joined: May 08, 2007 Posts: 2

I am trying to make submission form. Right now, there are 43000 cities. Too many. The cities are the children of the states.

I want a user to select THE STATE - then have the second pulldown generate the cities for that state only.

This stupid {form:category_list} is the back-end command for the pulldown.

The cities are in the db according to parent id number. PID.

$category_list = "";
$rrr = $row->cid ? $row->cid : "";
$this->html = str_replace("{form:category_list}", buildcatList($rrr), $this->html);

Posted: Wed May 09, 2007 6:34 am

freeword, two possible methods come to mind:

1. Where all the data is passed back to the browser and then via javascript and manipulation of the DOM, as the user changes the state form field, you trigger a javascript function which adusts the options that are listed in the city form field.

2. Using AJAX to dynamically query the database each time the state form field changes and then manipulate the city form field options.

Either way, you are going to have to get your hands real dirty and detailed into the coding. There is no easy way if you are wanting to avoid having to go back to the server and repaint the web page each and every time.

Posted: Wed May 09, 2007 6:37 am

Montego- My buddy and I will try the javascript tonight - let you know how it goes - the AJAX is beyond me still...

Posted: Wed May 09, 2007 7:08 am

Personally, I would do something like load up the cities into an array using the state's PID as the key... then, when the onchange event is triggered in the state field, have the javascript set the city option values/text to the right ones.

Of course, with everything, there is probably 10 different ways of doing it. Even in what I've described above, there are still multiple variations on how to actually accomplish it.

Good luck!