I'm playing around with "Modified Preorder Tree Traversal" as discussed in an article on sitepoint <http://www.sitepoint.com/article/hierarchical-data-database/>, which includes this function:
<?php function display_tree($root) { // retrieve the left and right value of the $root node $result = mysql_query('SELECT lft, rgt FROM tree '. 'WHERE title="'.$root.'";'); $row = mysql_fetch_array($result);
// start with an empty $right stack $right = array();
// now, retrieve all descendants of the $root node
$result = mysql_query('SELECT title, lft, rgt FROM tree '.
'WHERE lft BETWEEN '.$row['lft'].' AND '.
$row['rgt'].' ORDER BY lft ASC;'); // display each row
while ($row = mysql_fetch_array($result)) {
// only check stack if there is one
if (count($right)>0) {
// check if we should remove a node from the stack
while ($right[count($right)-1]<$row['rgt']) {
array_pop($right);
}
} // display indented node title
echo str_repeat(' ',count($right)).$row['title']."\n";// add this node to the stack $right[] = $row['rgt']; } } ?>
This is outputting a text-based tree of the data in the database, but what I'd like to do is modify it to output a series of nested ul's (unordered lists) to describe the nesting, rather than relying on spaces and newlines.
I've had a couple of attempts, with no luck... can someone shed some light on how this might be achieved?
--- Justin French http://indent.com.au -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
