Retrieve PHP Object from a select element - php

Question

I have write a code to create a select with PHP Object which is:
<?php
class Modulo {
var $nD;
var $nC;
var $nA;
function __construct($nD,$nC,$nA) {
$this->nD=$nD;
$this->nC=$nC;
$this->nA=$nA;
}
function toString(){
return $this->nD."-".$this->nC."-".$this->nA."<br>";
}
}
?>
Here is the method to build the select:
function loadModuleValid(){
$mod1 = new Modulo(4,3,3);
$mod2 = new Modulo(5,3,2);
$mod3 = new Modulo(4,4,2);
$mod4 = new Modulo(5,4,1);
$mod5 = new Modulo(4,5,1);
$mod6 = new Modulo(3,5,2);
$mod7 = new Modulo(3,4,3);
$mods = array($mod1,$mod2,$mod3,$mod4,$mod5,$mod6,$mod7);
$i = 0;
print "<h3>Seleziona il modulo</h3>";
print "<select id=\"d1\">";
foreach ($mods as $key ) {
print "<option value=\"{$i}\">{$key->toString()}</option>";
$i++;
}
print "</select>";
}
Now I have to retrive the selected object by the user when the she/he presses a button. How can I do ? I want the actual object not just it's value !

Answer 1

You can't pass an object through a form... well you could if you were to serialize it, pass the string and then unserialize it but you don't want to do that.
What you want to do is reference the object with an identifier:
function loadModuleValid(){
array(
'mod1' => new Modulo(4,3,3),
'mod2' => new Modulo(5,3,2),
// your other objects
)
$i = 0;
print "<h3>Seleziona il modulo</h3>";
print "<select id=\"d1\">";
foreach ($mods as $key => $object ) {
print "<option value=\"{$key}\">{$object->toString()}</option>";
$i++;
}
print "</select>";
}
Then on the backend you would fetch the object based on mod1 or whatever the array key is. However this requires creating this array of objects in a place where they can be fetched again.
So let's do an example of that:
function getModulos($id = null) {
$mods = array(
'mod1' => new Modulo(4,3,3),
'mod2' => new Modulo(5,3,2),
// your other objects
);
if (null !== $id) {
return isset($mods[$id]) ? $mods[$id] : false;
} else {
return $mods;
}
}
function loadModuleValid(){
$mods = getModulos();
$i = 0;
print "<h3>Seleziona il modulo</h3>";
print "<select id=\"d1\" name=\"modulo\">";
foreach ($mods as $key => $object ) {
print "<option value=\"{$key}\">{$object->toString()}</option>";
$i++;
}
print "</select>";
}
// this would be an example of your form handling
if (isset($_POST['modulo'])) {
$modulo = getModulos($_POST['modulo']);
}

Answer 2

There is a dark tricks, you can serialize your object :
print "<option value=\"" . serialize($key) . "\">{$key->toString()}</option>";
Then unserialize it to retrieve your object :
$mod = unserialize($_POST['yourSelectName']);