PHP tree menu, bottom-up - php

Question

I'm having some issues getting a tree menu to work from bottom-up.
I already have a script to work from top-down, which works fine.
This is a very simplified version of my table:
+-----+-----------+--------------------+
| uid | parent_id | page_address |
+-----+-----------+--------------------+
| 1 | 0 | index.php |
| 2 | 0 | login.php |
| 3 | 2 | dashboard.php |
| 4 | 3 | bookings.php |
| 5 | 3 | documents.php |
| 6 | 4 | changebookings.php |
| 7 | 4 | activities.php |
+-----+-----------+--------------------+
The page_address field is unique.
I can work out what page the user is currently on, for example changebookings.php
I would then like a menu to look like this:
login.php
dashboard.php
bookings.php
changebookings.php
activities.php
documents.php
However, the closest I've got so far is the following tree:
login.php
bookings.php
changebookings.php
As you can see, my script currently only returns the actual parent, and not a list of links currently in the parent.
For those interested, the script I use in total is at the bottom of this post.
Is there any easier way to get the bottom-up tree as required?
Many thanks
Phil
EDIT:
I've finally got the code to work, for future users who stumble upon this post, I have added the functionality below:
$dataRows = $databaseQuery->fetchAll(); // Get all the tree menu records
$dataRows = $result->fetchAll(PDO::FETCH_ASSOC);
foreach($dataRows as $row)
{
if($row['link_address']==substr($_SERVER['PHP_SELF'], 1, strlen($_SERVER['PHP_SELF'])-1))
{
$startingId = $row['parent_id'];
}
}
$menuTree = $this->constructChildTree($dataRows, $startingId);
private function constructChildTree(array $rows, $parentId, $nesting = 0)
{
$menu = array();
if(!in_array($nesting, $this->nestingData))
{
$this->nestingData[] = $nesting;
}
foreach($rows as $row)
{
if($row['parent_id']==$parentId && $parentId!=0)
{
$menu[] = $row['link_address'];
$newParentId = $this->getNextParent($rows, $row['parent_id']);
$parentChildren = $this->constructChildTree($rows, $newParentId, ($nesting+1));
if(count($parentChildren)>0)
{
foreach($parentChildren as $menuItem)
{
$menu[] = 'NESTING' . $nesting . '::' . $menuItem;
}
}
}
}
return $menu;
}
private function getNextParent($rows, $parentId)
{
foreach($rows as $row)
{
if($row['uid']==$parentId)
{
return $row['parent_id'];
}
}
}

Answer 1

Without reading your code you should be doing:
1) Get current page, look at parent ID.
2) Load all with that parent ID.
3) Get next Parent ID using current Parent ID as ID.
4) If new parent ID != 0, goto step 2 passing in the new Parent ID.
Sounds like you just need to edit your script to include ALL pages with the given ID as their parent ID.

Answer 2

<?PHP
$sql = "SELECT * FROM TABLE WHERE table parent_id=0";
$result = mysql_query($sql);
while($perant_menu = mysql_fetch_array($result))
{
echo display_child($perant_menu["uid"],$perant_menu["page_address"]);
}
// Recursive function
function display_child($parent_id,$name)
{
$sql= "SELECT * FROM table where parent_id = $parent_id";
$result = mysql_query($sql);
if(mysql_num_rows($result)>0)
{
while($menu = mysql_fetch_array($result))
{
echo display_child($menu["id"],$menu["page_address"]);
}
}
else
{
echo $name;
}
}
?>