php tree ul li hierarchy menu from array - php

Question

we have this array from mysqli query output :
$items = Array
(
Array
(
'id' => 1,
'title' => 'menu1',
'parent_id' => 0
),
Array
(
'id' => 2,
'title' => 'submenu1-1',
'parent_id' => 1
),
Array
(
'id' => 3,
'title' => 'submenu1-2',
'parent_id' => 1
),
Array
(
'id' => 4,
'title' => 'menu2',
'parent_id' => 0
),
Array
(
'id' => 5,
'title' => 'submenu2-1',
'parent_id' => 4
)
);
and we need this html output with php :
<ul>
<li><a>menu1</a>
<ul>
<li><a>submenu1-1</a></li>
<li><a>submenu1-2</a></li>
</ul>
</li>
<li><a>menu2</a>
<ul>
<li><a>submenu2-1</a></li>
</ul>
</li>
</ul>
can anyone help me ?
Probably this is very easy but I have tried everything already without success !!

Answer 1

finally i found answer like this:
function generateTreeMenu($datas, $parent = 0, $limit=0){
if($limit > 1000) return '';
$tree = '';
$tree = '<ul>';
for($i=0, $ni=count($datas); $i < $ni; $i++){
if($datas[$i]['parent_id'] == $parent){
$tree .= '<li><a>';
$tree .= $datas[$i]['title'].'</a>';
$tree .= generatePageTree($datas, $datas[$i]['id'], $limit++);
$tree .= '</li>';
}
}
$tree .= '</ul>';
return $tree;
}
echo generateTreeMenu($items);

Answer 2

//index elements by id
foreach ($items as $item) {
$item['subs'] = array();
$indexedItems[$item['id']] = (object) $item;
}
//assign to parent
$topLevel = array();
foreach ($indexedItems as $item) {
if ($item->parent_id == 0) {
$topLevel[] = $item;
} else {
$indexedItems[$item->parent_id]->subs[] = $item;
}
}
//recursive function
function renderMenu($items) {
$render = '<ul>';
foreach ($items as $item) {
$render .= '<li>' . $item->title;
if (!empty($item->subs)) {
$render .= renderMenu($item->subs);
}
$render .= '</li>';
}
return $render . '</ul>';
}
echo renderMenu($topLevel);

Answer 3

The problem here is just the structure of the array, so first you can convert the array to a more suitable structure, then you can draw your list easily.
Here is a function to convert the array:
function makeTree( $rst, $level, &$tree )
{
for ( $i=0, $n=count($rst); $i < $n; $i++ )
{
if ( $rst[$i]['parent_id'] == $level )
{
$branch = array(
'id' => $rst[$i]['id'],
'title' => $rst[$i]['title'],
'children' => array()
);
makeTree( $rst, $rst[$i]['id'], $branch['children'] );
$tree[] = $branch;
}
}
}
Mode of use:
$tree = array();
makeTree( $originalArray, 0, $tree );
At the end, you will have a new array in $tree structured as shown below, which you can easily draw in your view.
Array
(
[0] => Array
(
[id] => 1
[title] => menu1
[children] => Array
(
[0] => Array
(
[id] => 2
[title] => submenu1-1
[children] => Array
(
)
)
[1] => Array
(
[id] => 3
[title] => submenu1-2
[children] => Array
(
)
)
)
)
[1] => Array
(
[id] => 4
[title] => menu2
[children] => Array
(
[0] => Array
(
[id] => 5
[title] => submenu2-1
[children] => Array
(
)
)
)
)
)

Answer 4

Try this
$node = array();
foreach ($items as $item) {
if ($item['parent_id'] == 0) {
$node[$item['id']][$item['id']] = $item['title'];
} else {
$node[$item['parent_id']][$item['id']] = $item['title'];
}
}
$result = array();
foreach ($node as $key => $value) {
$result[$value[$key]] = array_diff($value, array($key => $value[$key]));
}