PHP Database driven Multilevel Menu - php

Question

I want to built a database driven multilevel menu I got it from [http://abhijitpal.in/][1] but the problem here is i can't put class = "dropdown" only to the top menus <ul>, it also get applies to the sub menus as well. I just modified a little but I don't know how to use recursive function. Below is the code, please see if you can help
<?php /** Function to display Catelogue Menu */
//select all rows from the main_menu table
$q ="SELECT * FROM catelogue WHERE cat_visibility = '1'";
$r = mysqli_query($dbc, $q);
//create a multidimensional array to hold a list of menu and parent menu
$menu = array(
'menus' => array(),
'parent_menus' => array()
);
//build the array lists with data from the menu table
while ($row = mysqli_fetch_assoc($r)) {
//creates entry into menus array with current menu id ie. $menus['menus'][1]
$menu['menus'][$row['cat_id']] = $row;
//creates entry into parent_menus array. parent_menus array contains a list of all menus with children
$menu['parent_menus'][$row['cat_parentid']][] = $row['cat_id'];
}
// Create the main function to build milti-level menu. It is a recursive function.
function nav_catelogue($parent, $menu) {
//$html = "";
if (isset($menu['parent_menus'][$parent])) { ?>
<ul>
<?php
foreach ($menu['parent_menus'][$parent] as $menu_id) {
if (!isset($menu['parent_menus'][$menu_id])) { ?>
<li><?php echo $menu['menus'][$menu_id]['cat_name']; ?></li>
<?php }
if (isset($menu['parent_menus'][$menu_id])) { ?>
<li><?php echo $menu['menus'][$menu_id]['cat_name']; ?>
<?php echo nav_catelogue($menu_id, $menu); ?>
</li>
<?php }
} ?>
</ul>
<?php }
}
?>
My Database structure is
-----------------------------------------
| cat_id | cat_name | cat_parentid |
-----------------------------------------
| 1 | Home | 0 |
| 2 | About | 0 |
| 3 | Contact | 0 |
| 4 | History | 2 |
| 5 | Services | 2 |
-----------------------------------------
Desired Output I want:
HOME
ABOUT
History
Services
Contact
This is the final code as per #Mave
<?php /** Function to display Catelogue Menu */
//select all rows from the main_menu table
$q ="SELECT * FROM catelogue WHERE cat_visibility = '1'";
$r = mysqli_query($dbc, $q);
//create a multidimensional array to hold a list of menu and parent menu
$menu = array(
'menus' => array(),
'parent_menus' => array()
);
//build the array lists with data from the menu table
while ($row = mysqli_fetch_assoc($r)) {
//creates entry into menus array with current menu id ie. $menus['menus'][1]
$menu['menus'][$row['cat_id']] = $row;
//creates entry into parent_menus array. parent_menus array contains a list of all menus with children
$menu['parent_menus'][$row['cat_parentid']][] = $row['cat_id'];
}
// Create the main function to build milti-level menu. It is a recursive function.
function nav_catelogue($parent, $menu, $top = false) {
if (isset($menu['parent_menus'][$parent])) {
//this is short code for if($top === true) { //do true } else { //do false }
echo $top ? '<ul class="dropdown">' : '<ul>';
foreach ($menu['parent_menus'][$parent] as $menu_id) {
if (!isset($menu['parent_menus'][$menu_id])) {
echo '<li>' . $menu['menus'][$menu_id]['cat_name'] . '</li>';
}
if (isset($menu['parent_menus'][$menu_id])) {
echo '<li>' . $menu['menus'][$menu_id]['cat_name'] . '' . nav_catelogue($menu_id, $menu) . '</li>';
}
}
echo '</ul>';
}
}
?>

Answer 1

function nav_catelogue($parent, $menu, $top = false) {
if (isset($menu['parent_menus'][$parent])) {
//this is short code for if($top === true) { //do true } else { //do false }
echo $top ? '<ul class="dropdown">' : '<ul>';
foreach ($menu['parent_menus'][$parent] as $menu_id) {
if (!isset($menu['parent_menus'][$menu_id])) {
echo '<li>' . $menu['menus'][$menu_id]['cat_name'] . '</li>';
}
if (isset($menu['parent_menus'][$menu_id])) {
echo '<li>' . $menu['menus'][$menu_id]['cat_name'] . '' . nav_catelogue($menu_id, $menu) . '</li>';
}
}
echo '</ul>';
}
}
When you first call nav_catelogue (not present in your current code), call it with nav_catelogue($menu_id, $menu, true);

Answer 2

You have two ways to make your recursive function put the
class="dropdown"
The first way is to go for a calling/callee style in which your calling function will treat the first case(class="dropdown") and then call the recursive function which will handle the general case(no class="dropdown").
Add an argument(boolean ?) that you'll transmit at first call and which will add the class="dropdown". On the recursive calls you'll transmit this boolean as false(no class="dropdown" insertion).