[FX.php List] Conditional value lists with PHP and FileMaker

[Anders Monsen]

Has anyone on the list worked on this issue? I spent most of yesterday  
putting together a process that works, but may not be the most  
efficient process. I was wondering if anyone would be open to looking  
at my code (the snippet is 130 lines long at minimum, so I didn't just  
want to throw it out there) to see if there are ways I can improve the  
process. It certainly made me appreciate how easy FileMaker makes this  
process...

(I just discovered and read Jonathan Stark's article in July  
FileMakerAdvisor after writing this email. It uses Ajax, so I may try  
to incorporate his techniques, although I'm using FX.php and no  
existing value lists from FileMaker, just existing data.)

Here's the scenario. I have a table with four fields: district number,  
district name, campus number, and campus name. I want the district and  
campus to be drop down menus, where the user sees the name but submits  
the number into another FileMaker database/table. Also, when the user  
selects a district, I need the value list of campuses to correspond  
just to their appropriate district.

My first issue was to find a way to create an associative array with  
district numbers=>district names. Apparently I took the hard route in  
dynamically building associative arrays... After several failed  
attempts, I used a function that I found on php.net in the section on  
"array_push" to create this array. The first problem I ran into was  
that the list currently contains 270 records. For now I had to  
manually change the groupsize in the query to above 300, but I plan to  
first query all records to get a count, then make this the groupsize.  
The reason for this is that the district array becomes unique only  
after all records have been loaded into the array, so the default  
groupsize of 50 has to be modified.

Is there a way to 1) build a better array and 2) make the district  
array unique in the initial query? The database is structured as one  
file, with all four fields, and so the district numbers and names are  
repeated. I didn't create the database, and I can't change it.
Distnum	|	Distname	| CampusNum	|	Campus Name
10			The ISD		2			School
10			The ISD		2.1			OtherSchool
etc.

Additionally, after several failed attempts to get the Javascript  
onchange function to work when the form changed, I resorted to  
DreamWeaver's JumpMenu, which seems to work fine. Has anyone been able  
to get a working onchange form and what is the correct syntax? When  
the user selects a district from the dropdown, the page reloads with  
the district number in the URL.

Given all of the above, my process *does* work, and the page does not  
appear to load with delays. I have not used conditional values lists  
with PHP/Javascript in about three years, so I am a little unsure of  
best practices.

Thanks,
Anders