Calling a function within itself *resolved*

[Graff]

I'm having a problem with a peice of code, it will execute fine except it won't go into the call.

function GetSubCategory($id,$str,$folder)
	{
		$db = OpenDB();
		
		$r = mysql_query("SELECT category_id,name,folder FROM category WHERE category_id <> ".$id." AND category_parent_id = ".$id,$db);
		
		while($row = mysql_fetch_array($r))
		{
			$r2 = mysql_query("SELECT count(*) as pages FROM Page p, category c WHERE p.category_id = c.category_id AND c.category_id = ".$row['category_id'],$db);
			$row2 = mysql_fetch_array($r2);
			$pages = $row2['pages']-1;		//ignore the index.php
			$folder += $row['folder']; 		//append new folder to existing
			echo $str."<a href='".$folder."'>".$row['name']." (".$pages.")</a><br>\n";
			$str += "<a href='".$folder."'>".$row['name']."</a>&gt;&gt;";
			GetSubCategory($row['id'],$str,$folder);
		}
		CloseDB($db);
	
	}

I don't get any warnings or error messages, it just stops.

[Graff]

ah just realized my error:

$row['id'],

should have been
$row['category_id'];

[CornedBee]

You should remove the OpenDB and CloseDB calls from the recursive function, you don't want to call them every time.

[Graff]

Yea, they were a throw back from when I was trying something else.

[phpman]

it is bad coding to call the same function in itself, it may get stuck in a loop and crash the server. just a bad idea all around.

[Graff]

I avoid recursion where possible if you can think of a better way to have a function get an indefinite amount of sub-categories from any given point within the tree I would definitly like to hear it.

[phpman]

yeah, using "traversal algorithm"

http://www.sitepoint.com/article/1105/1

much easier and a lot more flexable.

[Graff]

You still need to use recursion in the rebuild tree method

[phpman]

the modified preorder tree traversal algorithm doesn't use it if you do it right. I don't have anything calling itself in mine.