PHP Question
create menu array recursively
I have a single array containing menu items. Each item have its parent_id. I am searching and trying for many hours but can't figure out how to traverse the array recursively. I'm not good at recursion.
I have tried to use the code from the following post. It generates the html menu but it misses the 1st record also I want an array so I can make custom html menu out of the array.
Using recursion to build navigation
I have tried this code from an other post but it returns empty array.
create_array(-1, $array);
function create_array($number, $data)
{
$result = array();
foreach ($data as $row)
{
if ($row['parent_id'] == $number)
{
$result[$row['id']] = create_array($row['id'], $data);
}
}
return $result;
}
data array:
Array
(
[0] => Array
(
[id] => 1
[parent_id] => -1
[url] => /home
)
[1] => Array
(
[id] => 2
[parent_id] => 0
[url] => /page
)
[2] => Array
(
[id] => 3
[parent_id] => 2
[url] => /page/sub_page
)
[3] => Array
(
[id] => 4
[parent_id] => 3
[url] => /page/sub_page/inner_page/
)
)
result desired:
home - page
sub_page
inner_page
Any help will be very appreciated please.
Answer
What it should do is start by printing the ones with 0 as parent, for each one find it's children and start again for each children.
Something like:
function menu($data,$parent=-1) {
$res='';
foreach($data as $e) {
if($e['parent_id']==$parent||($parent==-1&&$e['parent_id']==0)) { //Also search for 0 when parent is -1 as are both the roots
$res.='<li>'.$e['url']; //Or whatever you want to show
$sub=menu($data,$e['id']);
if($sub) $res.='<ul>'.$sub.'</ul>';
$res.='</li>';
}
}
return $res;
}
<ul><?=menu($data)?></ul>
Source (Stackoverflow)