Script to create user groups model for NEREID project

createusergroups.php

<?php
/*
 * This script will be in charge of creating the user groups and setting their
 * proper permissions as we arranged. That is:
 *
 * 	Students: Will create articles and only edit their own. Inherits from Author
 * 	group in Joomla's predefined groups.
 * 	Visitors: Anyone that visits this site. No login necessary. Inherits from
 * 	Public.
 * 	Webmaster: The administrator group of this site. Inherits from SuperUser.
 *
 */

require 'configuration.php';
$config = new JConfig;

$usergroups_table = 'usergroups';

// create connection to our database
mysql_connect($config->host, $config->user, $config->password) 
	or die(mysql_error());
mysql_select_db($config->db)
	or die(mysql_error());

/* 
 * this function was taken from the documentation for Joomla 1.5 and adapted to v1.7
 * see: http://docs.joomla.org/Custom_user_groups 
 */
function rebuild_tree($parent_id, $left) {
 
	global $config;
	global $usergroups_table;
 
	// the right value of this node is the left value + 1
	$right = $left + 1;
 
	// get all children of this node
	$result = mysql_query(
		'SELECT id FROM ' . $config->dbprefix . $usergroups_table .
		' WHERE parent_id = ' . $parent_id . ';')
		or die(mysql_error());
 
	while ($row = mysql_fetch_array($result)) {
		// recursive execution of this function for each
		// child of this node
		// $right is the current right value, which is
		// incremented by the rebuild_tree function
		$right = rebuild_tree($row['id'], $right);
	}
 
	// we've got the left value, and now that we've processed
	// the children of this node we also know the right value
	mysql_query(
		'UPDATE ' . $config->dbprefix . $usergroups_table .
		' SET lft = ' . $left . ', rgt = ' . $right . 
		' WHERE id = ' . $parent_id . ';')
		or die(mysql_error());
 
	// return the right value of this node + 1
	return $right + 1;
}

// function that creates a group, it's just an insert command
function insert_group($group_name, $parent_id){
	
	global $config;
	global $usergroups_table;

	mysql_query(
		'INSERT INTO '. $config->dbprefix . $usergroups_table . ' (title, parent_id)'.
		' VALUES (\''. $group_name .'\', '. $parent_id .')'
	)
	or die(mysql_error());

}

// now create user groups
insert_group('Students', 3);		// 3 is the ID for Author, which is the parent_id we want
insert_group('Visitors', 1);		// 1 is the ID for Public
insert_group('Webmaster', 8);		// 8 is the ID of Super Users

// from the aforementioned site:
/* 
 * 0-> parent_id in Joomla this is the value of the parent_id field of the Root record
 * 1-> start the left tree at 1
 */
rebuild_tree (0, 1);

// print everything
Print 'User groups successfully created!<br />';

$user_groups = mysql_query("SELECT * FROM " . $config->dbprefix . $usergroups_table)
	or die(mysql_error());

while($row = mysql_fetch_array($user_groups))
{
	Print "<hr/>";
	Print "id:" . $row['id'] . "<br />";
	Print "parent_id: " . $row['parent_id']. "<br />";
	Print "lft: " . $row['lft']. "<br />";
	Print "rgt: " . $row['rgt']. "<br />";
	Print "title: " . $row['title']. "<br />";

}

?>