Här är ett exempel med rekursion.
function buildNavigation($items, $parent = NULL)
{
$hasChildren = false;
$outputHtml = '<ul>%s</ul>';
$childrenHtml = '';
foreach($items as $item)
{
if ($item['parent'] == $parent) {
$hasChildren = true;
$childrenHtml .= '<li>'.$item['category_name'];
$childrenHtml .= buildNavigation($items, $item['category_id']);
$childrenHtml .= '</li>';
}
}
// Without children, we do not need the <ul> tag.
if (!$hasChildren) {
$outputHtml = '';
}
// Returns the HTML
return sprintf($outputHtml, $childrenHtml);
}
print buildNavigation($items);
Det skriptet producerar följande utdata:
<ul>
<li>Menu 1</li>
<li>Menu 2
<ul>
<li>Sub Menu 2.1</li>
<li>Sub Menu 2.2</li>
<li>Sub Menu 2.3
<ul>
<li>Sub Menu 2.2.1</li>
<li>Sub Menu 2.2.2</li>
<li>Sub Menu 2.2.3</li>
</ul>
</li>
</ul>
</li>
<li>Menu 3</li>
</ul>