Create dynamic PHP / HTML category tree - php

Question

I've figured out how to fetch each parent/child with ul > li structure but now I'm stuck, the sub category ul's need a class 'dropdown' but can't figure this out.
My goal is to create an infinite dynamic ul menu with Foundation nav markup.
PHP
function fetchCategoryTreeList($parent = 0, $user_tree_array = '') {
$isParent = '';
if (!is_array($user_tree_array))
$user_tree_array = array();
$sql = "SELECT id,name,parent FROM `categories` WHERE 1 AND parent=$parent ORDER BY id ASC" or die(mysql_error);
if (database_querySelect($sql,$rows)) {
$user_tree_array[] = "<ul>";
foreach ($rows as $row) {
if ($row["parent"] == "0") { $isParent = "has-dropdown"; }
$user_tree_array[] = "<li class='".$isParent."'>". $row["name"]. "</li>";
$user_tree_array = fetchCategoryTreeList($row["id"], $user_tree_array);
}
$user_tree_array[] = "</ul>";
}
return $user_tree_array;
Code to display cat's
<?php
$res = fetchCategoryTreeList();
foreach ($res as $r) {
echo $r;
}
?>
Output
<ul>
<li class='has-dropdown'>Golf Equipment</li>
<ul>
<li class=''>Manual Golf Trolleys</li>
<li class=''>Electric Golf Trolleys</li>
</ul>
<li class='has-dropdown'>Weight Training</li>
<ul>
<li class=''>Weight Benches</li>
<li class=''>Weights</li>
</ul>
</li>
</ul>

Answer 1

My be it help .. I dont know (need a class 'dropdown') for what... you can give the main ul a Class
$user_tree_array[] = "<ul class='main_ul'>";
and then you can use selector in css and jquery
.main_ul .has-dropdown ul {
}

Answer 2

function:
<?php
function fetchCategoryTreeList( $parent = 0, $user_tree_array = "" ) {
if ( ! is_array($user_tree_array))
$user_tree_array = array();
$sql = "SELECT id,name,parent ";
$sql .= "FROM `categories` ";
$sql .= "WHERE 1 AND parent = {$parent} ";
$sql .= "ORDER BY id ASC";
if ( database_querySelect( $sql, $rows) )
{
foreach ( $rows as $row )
{
$user_tree_array[] = "<li class='' >{$row["name"]}</li>";
if ( $parent != $row["id"] )
{
$user_tree_array[] = "<ul>";
$user_tree_array = fetchCategoryTreeList( $connection, $row["id"], $user_tree_array );
$user_tree_array[] = "</ul>";
}
else
{
$user_tree_array = fetchCategoryTreeList( $row["id"], $user_tree_array );
}
}
}
return $user_tree_array;
}
?>
Call:
<?php
$arrays = fetchCategoryTreeList();
foreach ( $arrays as $list)
{
echo $list;
}
?>