Dynamically updating a listbox

usaindp1776

I have a PHP page that users need to select a State, and then a City within that State. Both values are displayed in their own listbox which gets it's information from a MySQL database.

Using PHP, Is there a way to get the page to dynamically update the values displayed in the City listbox to display only the valid cities when a user makes a selection from the State box? IF not, what would be the preferred method to do this in another language?

Thanks for the help!!

Bryan

LordShryku

With PHP, you'll need to submit the form to the server before it will be able to update the City listbox. You may want to try to use Javascript.

marque

I agree, javascript may be better for this, however, it all depends on how many cities there are in the usa, you would need to load all the cities into the page when it loads. The other alternative is ofcourse to load it via php, probably quicker for the user who uses a 56k modem.

the best way i know of is to select from the database their choice of state and step through the mysql_fetch_assoc() in the list.

osusano

why dont u try to make a code in php that will put all the value into a javascript and assigned it as an array then call the java script in your form so that no need to refresh your screen just put an on change function on your javascript 🙂

usaindp1776

I suppose I could use Javascript. The only problem is that I don't want to have to load the entire list of cities. It won't be a big deal at first, but as we add more states, the list may start taking a while to load on dialup connections.

Unless anyone has any other ideas, I may just go ahead and use 2 separate pages for now. One for the State selection and then submit and return the possible values for the State. Kind of clunky, but I don't want to have to spend a whole bunch of time coding this particular function.

Thanks again, guys. If I come up with anything else, I'll let you know.

Bryan

maybl8r03

You can load it using Remote scripting - search the web for Remote scripting Javascript and you will find quite a few examples.

One that gave me a good idea of how to (stay away from Microsoft proprietarty stuff) is http://dynarch.com/mishoo/rpc.epl which is based on http://www.oreillynet.com/pub/a/javascript/2002/02/08/iframe.html

In a nutshell, you will have a lightweight php in the background that just displays a string of values for your javascript to parse. If you are using the IFRAME method, you will have to create handlers in your parent document to receive the data from the IFRAME and you will have to create a mini script in your php that essesntially asks the IFRAME to send the data it receives to the parent document....

usaindp1776

Hmmm....The IFRAME idea is rather intriquing. I'll have to think about it. I'm quite new to web programming technologies and I would like to try and get a handle on PHP before I go trying to learn other languages. Hence I want to stay away from JavaScript and other techniques...at least for now.

Thanks goes to all.