Dynamic pulldown menus in PHP

kturby

Does anyone have an example of using MULTIPLE pulldown menus in PHP, each based upon the selection in the PREVIOUS pulldown?

For example, if I have three fields: STATES, PRODUCTS, COLORS.

1) In the STATES pulldown, the user picks the state.

2) Based upon which STATE is chosen, different PRODUCTS are listed in the PRODUCTS pulldown.

3) Based upon which PRODUCT is chosen, different COLORS are listed in the COLORS pulldown.

I've been able to do this in javascript, and am able to do single dynamic pulldowns in PHP, even to the point of populating the pulldown content from my SQL database. Where I'm stuck is getting multiple pulldowns on the same page, having the subsequent pulldown based upon the selection in the previous pulldown.

bastien

php is server side code you would need to submit the choice to the server and go from there...

kturby

So you're saying in PHP each pulldown would have to be on a separate screen and then passed to the next with ?item=value ?

Ick.

yahoka

I know this is possible, i've seen it done. If i could only remember where 🙁 It is easy php, but it has to do with javascript methinks.

superwormy

You definitally cannot do this entirely with PHP...

PHP is server side... once the data is sent, you could use Javascript to build and display the menus.

But PHP would have nothing to do with actually building the menus / making the menus be able to display other pullldown menus. It woudl just provide text content, Javascript would do the rest.

sarahk

If you look at some of the bigger systems, like Selectica, when the user changes any field which means that other choices will change the form is submitted and "redrawn" for want of a better term. When it comes back the back end system has reconfigured all the drop downs, choices and fields may be removed or added or changed depending on the choice. This is an accepted process. Only problem is the poor old user who has screen "flicker" and if on dialup considerable delays.

IF You do this consider that the form should not involve scrolling or the user will continually lose the place on the form and you have to use javascript to control that and it starts getting really messy.

benwestgarth

It can be done but it relies strongly on javascript. Also, when you get to the third select box, there are a lot of choices and unless you want to spend the rest of your life hardcoding it and producing alot of work which will be almost impossible to maintain then I would recommend building a good relational database behind the scenes and populating the select boxes from db queries.

I did this about a year ago and I just dug the code out for it. I'm sure it isn't as tidy as it could be, and I'm not really sure what the hell I put some of it in there for, but I know it works.

Alot of the code is specific to my database, and it is a poor example of commenting one's code, but you are welcome to plough through it and adapt it to your needs. Also, alot of it seems very unnecessary now that I look at it, but I remember having a hard time getting the PHP and JavaScript to play nicely. If you have any questions about any part of the code then just let me know.

kturby

Thanks! I'll take a look through that and see what I can do with it.

In the meantime, I've altered how I ask the user for the selections by asking each question on a separate screen and passing the results in the subsequent URL. It works, but it's a bit of a pain for the user.

gigowiz

Here's an example of what you're asking for. The first time the script is called it displays the attorney names. The user selects a name and clicks Submit. The selected name is used to obtain the case numbers for that attorney. Those case numbers are displayed in a drop down box in a separate form and the previously selected attorney name is displayed in it's drop down list. If the user selects a different attorney name and clicks Submit then the case number drop down box is recreated with that attorney's cases and that attorney's name is displayed in it's drop down list.

Hope this helps.

Hank

++++++++++++++++++++++++++++++
$sel_c = pg_exec($db_conn, "SELECT distinct(d_counsel) FROM deft_counsel order by d_counsel");
print("<form method=post action=\"/xxxx/deft_counsel_cases.php\">\n");
print("<table width=400 border=0><tr align=center><td>\n");
print("<select size=1 name=d_counsel>\n");

$num_c = pg_numrows($sel_c);
for($i=0; $i<$num_c; $i++) {
$arr1 = pg_fetch_array($sel_c, $i);
if ($d_counsel == trim($arr1["d_counsel"])) {
printf("<option value=\"%s\" selected>%s\n", trim($arr1["d_counsel"]), trim($arr1["d_counsel"]));
}
else {
printf("<option value=\"%s\">%s\n", trim($arr1["d_counsel"]), trim($arr1["d_counsel"]));
}
} / END FOR LOOP /
print("</select></td></tr></table>\n");
print("<input type=submit value=\"Select Counsel\"></form>\n");
print("<br><font size=3 color=990000>Select a Counsel from the drop down list and click the Select Counsel button</font><p>\n");

if (strlen($d_counsel) > 0) { / If we have selected an attorney name /
print("<form method=post action=\"/xxxx/process_srch_case.php\">\n");
$sel_id = pg_exec($db_conn, "select deft_id from deft_counsel where d_counsel = '$d_counsel'");
$num_ids = pg_numrows($sel_id);
print("<font size=3>Case Nbr - Defendant Name</font>\n");
print("<table width=400 border=0><tr align=center><td>\n");
print("<select size=1 name=case_nbr>\n");

for ($j=0; $j<$num_ids; $j++) {
$arr_id = pg_fetch_array($sel_id, $j);
$deft_id = $arr_id["deft_id"];
$sel_case = pg_exec($db_conn, "SELECT deft, case_nbr FROM defendant where deft_id = $deft_id order by case_nbr");
$num_cases = pg_numrows($sel_case);
for($i=0; $i<$num_cases; $i++) {
$arr1 = pg_fetch_array($sel_case, $i);
printf("<option value=\"%s\">%s - %s\n", trim($arr1["case_nbr"]), trim($arr1["case_nbr"]), trim($arr1["deft"]));
}
}
print("</select></td></tr></table>\n");
print("<input type=submit value=\"View Case\"></form>\n");
print("<p><font size=3 color=990000>Select a Case Number to view or go up and select a different counsel</font>\n");
}

kturby

Thanks gigowiz, I'll try that. I gave the previous example a whirl, but was unable to get it to work, even after trying to create and connect to identically named tables and fields with dummy data.