php, forms, & $php_self

[Anon]

Hi, and thanks in advance for helping me out:

let me show you the follwoing little snippit of code:

//form
echo "
<form action=pipedesignpressure_result.php method=post>
Please select the Spec. Number to find the
<br>
Specified Maximum Yield Strength of a steel pipe:
<br>
<select name=spec_id">")
<option value=\"\">Spec. No.</option>
";

// sql query one
$sqlone = "SELECT * FROM smys_spec";
$resultone = mysql_query($sqlone)
or die("Failed to complete the query");

// first drop down loop
while ($rowone = mysql_fetch_array($resultone))
{
$spec_id = $rowone["id"];
$spec = $rowone["spec"];

//make the first drop down list
echo "
<option value=\"$spec\">$spec</option>
";
}

//close the form
echo "
</select>
</form>
";
?>

ok now what i want is to add more drop down menues that react to the chosen value from the above drop down. now i have heard and tried to understand chainselectors but it has too much JS for me to understand. not yet anyway.

so what i thought about doing is to have the page refresh on a onchange event. for example if i were to choose an option from the first dropdown the page would reload and the second dropdown would update. But i can't seem to make "$php_self" work. i don't know how...can someone please help..im desperate.

Thanks..

Mike

[Anon]

So let me summarize really briefly...
<ol>
<li>you create dynamically a drop down menu
<li>you want to select a value from this menu and based on what value selected you have another drop down menu that pops up.
<li>you want to use $PHP_SELF to get that done
</ol>
I am not going to type the code, but I will give you a conceptual model.
<hr>
First thing you need to do is what you did - create script to dynamically generate the first form. In the last line of the form where you have your submit button you need to name it <input type=submit value=Click <b>name=enter</b>>. Of course the first line will be <form method=post action=$PHP_SELF>. You will also have to name the select tags <select name=choice>, we will use it in switch statement.

<b>Note:</b> The above script has to be in a lower part of the file, because the processing sript will be located in the upper part of the file.

Now the processing sript.

if($enter)
{
switch($choice) \
{
below you type all the choices available from your first form.

case 1:
Here you inlude the first drop down menu form
break;

   case 2:
   Here you include the second dro down menu form
   break;

  and etc.

}

To simplify this whole process I suggest that you write a class, which will make things simpler and updating code will be much easier.

For example:

if($enter)
{
include("dropdownclass.php");
$obj=new Class; \whatever the name of your class
and then
you do this:
switch($choice)
{
case 1:
$obj->form1; \instead of typing the whole form you just call it from the class
break;

case 2:
$obj->form2;
break;

etc.
}

This is just a concept, but... every single methodology is built upon a logical model, so the rest is up to you.

Hope that helped,

Di

[Anon]

umm..it helped a little, but im afraid not much. im new to php so i don't quite understand what you mean.

And besides, what i really wanted was the form or page to reload on a onchange event..not when the user clicks the submit button...

thanks anyway..i got something in mind that i will see if it works. ( i doubt it will)

Thanks,
Mike

[Anon]

PHP doesn't support onchange events. May be you are confusing it with JavaScript.

I guess what you are trying to do relates strictly to clinet side. PHP is server side. www.programmingtutorials.com has some stuff on JavaScript.

Di

[Anon]

actually it worked..i had it working and everthing..

i had it so through javascript the page reloads. then i check for a variable..that i posted using $php_self?a=$whatever

if its there then php generates another drop down box...but about after 5 drop downs..i decided it didn't look good refreshing and expanding all the time...

so i scrapped it and did something else..wich works just fine...

thanks for you help though...

Mike