Using AJAX to pass variable into PHP array - php

Question

I have looked around various other questions relating to this topic but I am still struggling to find a solution to my query.
In my system I am allowing the admin to append extra form nodes to the file so they may input any extra required data, this data is then submitted to the DB to generate pages in the main portion of the site.
I am new to the concept of passing the data back via AJAX so I may be misunderstanding something but here is my code.
Add Node Control
<div id="nodeControl">
<div id="addNode">
<a id="nodeLink" href="#">+</a>
</div>
</div>
<div id="slideOut">Click to add a new section</div>
Add Node click response function
var nodeCount = 2;
$("#nodeLink").click(function(){
// Local Variables
var newSection = '<br/><div id="sectionInfo"><div id="sectionWrap"><div id="sectionInner"><label class="inst head">Section ' + nodeCount + '</label><input class="textOver" type="text" name="sectionTitle' + nodeCount + '" value="<?php $title; ?>"> <label class="inst ib">Please enter any text you would like associated with the section.</label> <textarea style="margin-top: 3px" name="sectionContent' + nodeCount + '" value="<?php $body; ?>"></textarea> <label class="inst ib">Please upload the image associated with this section, .PNG reccomended.</label> <input type="file" style="visibility:hidden;" name="img' + nodeCount + '" id="upload" /> <input type="button" id="fileStyle" class="fSOver" value="Upload Pump Image!" /> </div> </div> </div>' ;
// Append the new section to the document and increment the node count
$('#sections').append(newSection);
nodeCount += 1;
// Call AJAX to pass to PHP
$.ajax({
type: "POST",
url: "../section.php",
data: { setSection : newSection },
success: function() {
alert("Success, ajax parsed");
}
});
$(".successDiv").slideDown(150);
$(".successDiv").delay(1500).slideUp(150);
return false;
});
Node count is instantiated to "2" here, when a node is added the number is appended to the name attribute of any input elements on my form i.e. header2, header3 etc.
This is so when my form is eventually submitted I can loop through each data field and submit it to the database.
As I currently understand the AJAX data variable uses key pairs { a : b } where a = return key and b = return value, I want PHP to be able to access that returned value and store it into an array which can be looped through at the end.
Currently the success message is triggered on my AJAX call but I am unable to access the values in PHP, instead I am thrown an "Undefined index of sections defined".
$section = array();
$setSection = $_POST['setSection'];
$section[] = $setSection;

Answer 1

PHP won't store every setSection variable you pass it over time; each time your script is called, its variables are reset. You probably want to store the variable in a database or session variable.
Here's one approach, using session variables:
session_start(); // unless you already started one
if (!isset($_SESSION['section'])) {
$_SESSION['section'] = array();
}
array_push($_SESSION['section'], $_POST['setSection']);