Passing array with ajax - can't print - php

Question

I hope this problem is very simple, I can't figure out the solution myself it seems. Been trying and googling for hours, driving me nuts :) Ok, so I have a drag'n'drop + sortable (using scriptaculous and prototype for your information) on my index.php. I use this code to send the items dropped in a div using this code:
<script type="text/javascript">
//<![CDATA[
document.observe('dom:loaded', function() {
var changeEffect;
Sortable.create("selectedSetupTop", {containment: ['listStr', 'selectedSetupTop'], tag:'img', overlap:'vertical', constraint:false, dropOnEmpty: true,
onChange: function(item) {
var list = Sortable.options(item).element;
$('changeNotification').update(Sortable.serialize(list).escapeHTML());
if(changeEffect) changeEffect.cancel();
changeEffect = new Effect.Highlight('changeNotification', {restoreColor:"transparent" });
},
onUpdate: function(list) {
new Ajax.Request("script.php", {
method: "post",
parameters: { data: Sortable.serialize(list), container: list.id }
onLoading: function(){$('activityIndicator').show(), $('activityIndicator2').hide()},
onLoaded: function(){$('activityIndicator').hide(), $('activityIndicator2').show()},
});
}
});
});
// ]]>
</script>
I've been using this code before so I "kind of know" it will send me data to my script.php page. selectedSetupTop is my div containing the elements. Don't mind about the notification and the activityIndicator thingy. My script.php page looks like this for the moment:
parse_str($_POST['data']);
for ($i = 0; $i < count($selectedSetupTop); $i++) {
$test .= $selectedSetupTop[$i];
}
echo "<script>alert('$test');</script>";
I can't seem to get any output in the alert message, it's just blank. The purpose of the script.php is to update a row in a database and it will look kind of like this:
$sql = mysql_query("UPDATE table SET row = '$arrayInStringFormat' WHERE id = '1'") or die(mysql_error());
where the $arrayInStringFormat is a conversion of the array $selectedSetupTop to the format (1, 2, 3, 4). I guess I'll solve that using implode or something, but the problem is parsing the array $selectedSetupTop. I'm not it passes between the pages at all, really appreciate help! Tell me if I need to explain further.
Thanks in advance!
''''''
EDIT 1
If it will help, I used this code before that I know will send me the data and use it. Notice I don't wanna do my task like the way I do below:
$querySetup = $_GET["s"];
parse_str($_POST['data']);
for ($i = 0; $i < count($selectedSetupTop); $i++) {
$sql = mysql_query("UPDATE " . $querySetup . " SET orderId = $i, hero_selected = 'n' WHERE imageId = $selectedSetupTop[$i]") or die(mysql_error());
}
''''''
EDIT 2
So it does parse, but I still have the problem I can't print it. I wanna implode the array somehow.

Answer 1

Not sure how AJAX works in Scriptalicious/Prototype, but you don't seem to be getting the data from the AJAX call. In jQuery it would be something like this where the data you receive from the script is returned as the argument of the function.
onLoaded: function(msg){
$('activityIndicator').hide(),
$('activityIndicator2').show(),
alert(msg)
}
Secondly, you can't echo a PHP array, you have to encode it to JSON:
echo json_encode($test);