Building Dynamic Forms

webbgroup_net

Greetings fellow PHP'ers

I am trying to build a form that allows the user to choose the options from a large zipcode database that we have. What we would like to do is for the user to enter in the State, City, and Zip code based on data going to and coming back from the database.

Here is the scenario:

User selects the State from which they are in from a form dropdown menu.

(A query from the zip code database gets done and brings up the cities and fills in the next dropdown menu dynamically)

Then the user selects a City

(A query from the zip code database gets done and brings up the zip codes from the city entered above for the next dropdown menu dynamically)

The user select which Zip Code they live in.

PROBLEM: I want the form dropdown menus to be generated automatically when the user selects the option from the previous menu. I know how to do the above if the users go from form to form filling out information. But in this case, it would be much simplier to just have the choices be generated dynamically. I know that I will need to do an OnChange command for the menu, but alas my Javascript Programming isn't up to par.

Does anybody know where I can find more any information about doing something like this?? I have been scouring Google for the past day and a half and haven't found what I needed.

stolzyboy

you will have to go from form to form if you when quering the db with php, since it is server side, and you can do this with onchange, but the page will have to be submitted in some way

drawmack

Actually you have two options that do not involve going from form to form.

If it is not going to be run over the internet then you could look into gtk.

OTOH if it is going to be run over the internet you could use javascript to dynamically change the values in the form fields and use php to generate the javascript.

paul088

drawmack, can you talk a little more about using javascript to change form inputs dynamically? Thanks.

Weedpacket

Dunno if the Javascript solution is a smart one - it would mean downloading all the cities for all the states, and all the zip codes for all the cities, when the page loads. Basically, the entire zip code table would need to be downloaded onto the client so that the information is there for the Javascript to switch between. How big would that be?

matt_4013

I would recommend that EVERYBODY have a look at this.

http://ashleyit.com/rs/

This is what you want, but it does require the user have cookies turned on.

drawmack

Originally posted by Weedpacket
Dunno if the Javascript solution is a smart one - it would mean downloading all the cities for all the states, and all the zip codes for all the cities, when the page loads. Basically, the entire zip code table would need to be downloaded onto the client so that the information is there for the Javascript to switch between. How big would that be?

Not if you have the program maintain and xml version of the table, then javascript could just reference the xml file.

If you are interested in how to do this in javascript please see http://www.docjavascript.com

paul088

There was a post in the forums asking about how to automatically transfer contact info that were just entered, to billing address if a checkbox is checked (without submitting the form). Though this is not necessary in real world, how this is done is very interesting, and could be useful in other situations.

stolzyboy

its done with javascript

paul088

Could you point a direciton, please?

stolzyboy

here ya go, should get you headed in the right direction

Weedpacket

Originally posted by drawmack
Not if you have the program maintain and xml version of the table, then javascript could just reference the xml file.

If you are interested in how to do this in javascript please see http://www.docjavascript.com

Interesting (though a more accurate link would have been useful). So how does the Javascript code on the client update all the lists without downloading everything in advance and without hitting the server for bits and pieces? What, in short, does the XML do except add another layer of processing?

Personally, I prefer the IFRAMEd Javascript RPC; it means a client-server round trip, but that should still be smaller than the time it would take to download vast amounts of irrelevacy.

stolzyboy

i agree with weedpacket, regardless of where you get the information about the states/zips/etc... be it a database, text file, xml format, it still has to pull all that information at one time, it would be better to grab the state, and onchange have it submit and then guery the zips, etc..., may not seem as elegant, but it won't make someone on a dialup kill themself waiting for the page to load

paul088

Thanks, stolzyboy. I got the idea.

Paul