Make a Dynamic Drop Down Navigation system - php

Question

I am trying to create a Dropdown Menu on my site, Ive hit a brick wall and cannot think on how to do it.
Basically i need to check 2-3 variables in a database and out put the correct data.
I have at the moment it checking if its an External Link or Not, and if it contains a submenu, but i can't get it to output the correct information.
Basically i want it to check if its a External or Non-External link, and if it has a submenu, if it has a submenu, to display the menu options underneath it. So say i have menu 1, 2 ,3, 4 and 2,4 has a submenu, i need them to list the other links under them. i have put in my database toplink_id (to represent which link this item should be under) sc_order (which will control the order the sublinks display in) also dropdown (which tells me if the menu has a submenu or not.)
Here is the start of my code
$sql = "SELECT label, url, ext, dropdown FROM content_pages WHERE top_nav='1' AND active='1' ORDER by page_order ASC";
$query = mysqli_query($dbc, $sql) or die (mysqli_error($dbc));
$menuDisplay .= '<div class="bg-2"><div class="container_12"><article class="grid_12"><nav><ul class="menu sf-js-enabled">';
while ($row = mysqli_fetch_array($query)) {
$url = $row["url"];
$nav_label = $row["label"];
$drop_down ='<ul><li>' . $nav_label . '</li></ul>';
if ($row["ext"] == 0 && $row["dropdown"] == 1){
$menuDisplay .= '<li>' . $nav_label . '' . $drop_down . '</li>';
}
elseif ($row["ext"] == 1 && $row["dropdown"] == 1){
$menuDisplay .= '<li>' . $nav_label . '' . $drop_down . '</li>';
}
elseif ($row["ext"] == 0){
$menuDisplay .= '<li>' . $nav_label . '</li>';
}
elseif ($row["ext"] == 1)
{
$menuDisplay .= '<li>' . $nav_label . '</li>';
}
}
$menuDisplay .= '</ul></nav></article></div></div></header>';
mysqli_free_result($query);

Answer 1

Best way I found to do this without using jQuery is use multidimensional Arrays.
// Create a multidimensional array to conatin a list of items and parents
$menu = array(
'items' => array(),
'parents' => array(),
);
// Builds the array lists with data from the menu table
while ($items = mysqli_fetch_assoc($query))
{
// Creates entry into items array with current menu item id ie. $menu['items'][1]
$menu['items'][$items['id']] = $items;
// Creates entry into parents array. Parents array contains a list of all items with children
$menu['parents'][$items['parent']][] = $items['id'];
}
// Menu builder function, parentId 0 is the root
function buildMenu($parent, $menu)
{
$html = "\n";
if ( isset($menu['parents'][$parent]) )
{
$html .= "";
foreach ($menu['parents'][$parent] as $itemId)
{
if(!isset($menu['parents'][$itemId]) && $menu['items'][$itemId]['ext'] == 0)
{
$html .= "<li>\n <a href='../pages/".$menu['items'][$itemId]['link']."'>".$menu['items'][$itemId]['label']."</a>\n</li> \n";
}
else
if(!isset($menu['parents'][$itemId]) && $menu['items'][$itemId]['ext'] == 1)
{
$html .= "<li>\n <a href='../".$menu['items'][$itemId]['link']."'>".$menu['items'][$itemId]['label']."</a>\n</li> \n";
}
if(isset($menu['parents'][$itemId]))
{
$html .= "<li>\n <a href='../pages/".$menu['items'][$itemId]['link']."'>".$menu['items'][$itemId]['label']."<span class='arrow-down'></span></a> \n";
$html .= "<ul style='border-radius: 0px 0px 6px 6px'> \n";
$html .= buildMenu($itemId, $menu);
$html .= "</ul> \n";
$html .= "</li> \n";
}
}
$html .= "\n";
}
$html .= "";
return $html;
}