/libraries/joomla/installer/adapters/component.php

<?php

/**

 * @version		$Id:component.php 6961 2007-03-15 16:06:53Z tcp $

 * @package		Joomla.Framework

 * @subpackage	Installer

 * @copyright	Copyright (C) 2005 - 2008 Open Source Matters. All rights reserved.

 * @license		GNU/GPL, see LICENSE.php

 * Joomla! is free software. This version may have been modified pursuant

 * to the GNU General Public License, and as distributed it includes or

 * is derivative of works licensed under the GNU General Public License or

 * other free or open source software licenses.

 * See COPYRIGHT.php for copyright notices and details.

 */



// Check to ensure this file is within the rest of the framework

defined('JPATH_BASE') or die();



/**

 * Component installer

 *

 * @package		Joomla.Framework

 * @subpackage	Installer

 * @since		1.5

 */

class JInstallerComponent extends JObject

{

	/**

	 * Constructor

	 *

	 * @access	protected

	 * @param	object	$parent	Parent object [JInstaller instance]

	 * @return	void

	 * @since	1.5

	 */

	function __construct(&$parent)

	{

		$this->parent =& $parent;

	}



	/**

	 * Custom install method for components

	 *

	 * @access	public

	 * @return	boolean	True on success

	 * @since	1.5

	 */

	function install()

	{

		// Get a database connector object

		$db =& $this->parent->getDBO();



		// Get the extension manifest object

		$manifest =& $this->parent->getManifest();

		$this->manifest =& $manifest->document;



		/**

		 * ---------------------------------------------------------------------------------------------

		 * Manifest Document Setup Section

		 * ---------------------------------------------------------------------------------------------

		 */



		// Set the extensions name

		$name =& $this->manifest->getElementByPath('name');

		$name = JFilterInput::clean($name->data(), 'cmd');

		$this->set('name', $name);



		// Get the component description

		$description = & $this->manifest->getElementByPath('description');

		if (is_a($description, 'JSimpleXMLElement')) {

			$this->parent->set('message', $description->data());

		} else {

			$this->parent->set('message', '' );

		}



		// Get some important manifest elements

		$this->adminElement		=& $this->manifest->getElementByPath('administration');

		$this->installElement	=& $this->manifest->getElementByPath('install');

		$this->uninstallElement	=& $this->manifest->getElementByPath('uninstall');



		// Set the installation target paths

		$this->parent->setPath('extension_site', JPath::clean(JPATH_SITE.DS."components".DS.strtolower("com_".str_replace(" ", "", $this->get('name')))));

		$this->parent->setPath('extension_administrator', JPath::clean(JPATH_ADMINISTRATOR.DS."components".DS.strtolower("com_".str_replace(" ", "", $this->get('name')))));



		/**

		 * ---------------------------------------------------------------------------------------------

		 * Basic Checks Section

		 * ---------------------------------------------------------------------------------------------

		 */



		// Make sure that we have an admin element

		if ( ! is_a($this->adminElement, 'JSimpleXMLElement') )

		{

			JError::raiseWarning(1, JText::_('Component').' '.JText::_('Install').': '.JText::_('The XML file did not contain an administration element'));

			return false;

		}



		/**

		 * ---------------------------------------------------------------------------------------------

		 * Filesystem Processing Section

		 * ---------------------------------------------------------------------------------------------

		 */



		/*

		 * If the component site or admin directory already exists, then we will assume that the component is already

		 * installed or another component is using that directory.

		 */

		if ((file_exists($this->parent->getPath('extension_site')) || file_exists($this->parent->getPath('extension_administrator'))) && !$this->parent->getOverwrite()) {

			JError::raiseWarning(1, JText::_('Component').' '.JText::_('Install').': '.JText::_('Another component is already using directory').': "'.$this->parent->getPath('extension_site').'"');

			return false;

		}



		// If the component directory does not exist, lets create it

		$created = false;

		if (!file_exists($this->parent->getPath('extension_site'))) {

			if (!$created = JFolder::create($this->parent->getPath('extension_site'))) {

				JError::raiseWarning(1, JText::_('Component').' '.JText::_('Install').': '.JText::_('Failed to create directory').': "'.$this->parent->getPath('extension_site').'"');

				return false;

			}

		}



		/*

		 * Since we created the component directory and will want to remove it if we have to roll back

		 * the installation, lets add it to the installation step stack

		 */

		if ($created) {

			$this->parent->pushStep(array ('type' => 'folder', 'path' => $this->parent->getPath('extension_site')));

		}



		// If the component admin directory does not exist, lets create it

		$created = false;

		if (!file_exists($this->parent->getPath('extension_administrator'))) {

			if (!$created = JFolder::create($this->parent->getPath('extension_administrator'))) {

				JError::raiseWarning(1, JText::_('Component').' '.JText::_('Install').': '.JText::_('Failed to create directory').': "'.$this->parent->getPath('extension_administrator').'"');

				// Install failed, rollback any changes

				$this->parent->abort();

				return false;

			}

		}



		/*

		 * Since we created the component admin directory and we will want to remove it if we have to roll

		 * back the installation, lets add it to the installation step stack

		 */

		if ($created) {

			$this->parent->pushStep(array ('type' => 'folder', 'path' => $this->parent->getPath('extension_administrator')));

		}



		// Find files to copy

		foreach ($this->manifest->children() as $child)

		{

			if (is_a($child, 'JSimpleXMLElement') && $child->name() == 'files') {

				if ($this->parent->parseFiles($child) === false) {

					// Install failed, rollback any changes

					$this->parent->abort();

					return false;

				}

			}

		}



		foreach ($this->adminElement->children() as $child)

		{

			if (is_a($child, 'JSimpleXMLElement') && $child->name() == 'files') {

				if ($this->parent->parseFiles($child, 1) === false) {

					// Install failed, rollback any changes

					$this->parent->abort();

					return false;

				}

			}

		}



		// Parse optional tags

		$this->parent->parseMedia($this->manifest->getElementByPath('media'));

		$this->parent->parseLanguages($this->manifest->getElementByPath('languages'));

		$this->parent->parseLanguages($this->manifest->getElementByPath('administration/languages'), 1);



		// Parse deprecated tags

		$this->parent->parseFiles($this->manifest->getElementByPath('images'));

		$this->parent->parseFiles($this->manifest->getElementByPath('administration/images'), 1);



		// If there is an install file, lets copy it.

		$installScriptElement =& $this->manifest->getElementByPath('installfile');

		if (is_a($installScriptElement, 'JSimpleXMLElement')) {

			// Make sure it hasn't already been copied (this would be an error in the xml install file)

			if (!file_exists($this->parent->getPath('extension_administrator').DS.$installScriptElement->data()))

			{

				$path['src']	= $this->parent->getPath('source').DS.$installScriptElement->data();

				$path['dest']	= $this->parent->getPath('extension_administrator').DS.$installScriptElement->data();

				if (!$this->parent->copyFiles(array ($path))) {

					// Install failed, rollback changes

					$this->parent->abort(JText::_('Component').' '.JText::_('Install').': '.JText::_('Could not copy PHP install file.'));

					return false;

				}

			}

			$this->set('install.script', $installScriptElement->data());

		}



		// If there is an uninstall file, lets copy it.

		$uninstallScriptElement =& $this->manifest->getElementByPath('uninstallfile');

		if (is_a($uninstallScriptElement, 'JSimpleXMLElement')) {

			// Make sure it hasn't already been copied (this would be an error in the xml install file)

			if (!file_exists($this->parent->getPath('extension_administrator').DS.$uninstallScriptElement->data()))

			{

				$path['src']	= $this->parent->getPath('source').DS.$uninstallScriptElement->data();

				$path['dest']	= $this->parent->getPath('extension_administrator').DS.$uninstallScriptElement->data();

				if (!$this->parent->copyFiles(array ($path))) {

					// Install failed, rollback changes

					$this->parent->abort(JText::_('Component').' '.JText::_('Install').': '.JText::_('Could not copy PHP uninstall file.'));

					return false;

				}

			}

		}



		/**

		 * ---------------------------------------------------------------------------------------------

		 * Database Processing Section

		 * ---------------------------------------------------------------------------------------------

		 */



		/*

		 * Let's run the install queries for the component

		 *	If backward compatibility is required - run queries in xml file

		 *	If Joomla 1.5 compatible, with discreet sql files - execute appropriate

		 *	file for utf-8 support or non-utf-8 support

		 */

		$result = $this->parent->parseQueries($this->manifest->getElementByPath('install/queries'));

		if ($result === false) {

			// Install failed, rollback changes

			$this->parent->abort(JText::_('Component').' '.JText::_('Install').': '.JText::_('SQL Error')." ".$db->stderr(true));

			return false;

		} elseif ($result === 0) {

			// no backward compatibility queries found - try for Joomla 1.5 type queries

			// second argument is the utf compatible version attribute

			$utfresult = $this->parent->parseSQLFiles($this->manifest->getElementByPath('install/sql'));

			if ($utfresult === false) {

				// Install failed, rollback changes

				$this->parent->abort(JText::_('Component').' '.JText::_('Install').': '.JText::_('SQLERRORORFILE')." ".$db->stderr(true));

				return false;

			}

		}



		// Time to build the admin menus

		$this->_buildAdminMenus();



		/**

		 * ---------------------------------------------------------------------------------------------

		 * Custom Installation Script Section

		 * ---------------------------------------------------------------------------------------------

		 */



		/*

		 * If we have an install script, lets include it, execute the custom

		 * install method, and append the return value from the custom install

		 * method to the installation message.

		 */

		if ($this->get('install.script')) {

			if (is_file($this->parent->getPath('extension_administrator').DS.$this->get('install.script'))) {

				ob_start();

				ob_implicit_flush(false);

				require_once ($this->parent->getPath('extension_administrator').DS.$this->get('install.script'));

				if (function_exists('com_install')) {

					if (com_install() === false) {

						$this->parent->abort(JText::_('Component').' '.JText::_('Install').': '.JText::_('Custom install routine failure'));

						return false;

					}

				}

				$msg = ob_get_contents();

				ob_end_clean();

				if ($msg != '') {

					$this->parent->set('extension.message', $msg);

				}

			}

		}



		/**

		 * ---------------------------------------------------------------------------------------------

		 * Finalization and Cleanup Section

		 * ---------------------------------------------------------------------------------------------

		 */



		// Lastly, we will copy the manifest file to its appropriate place.

		if (!$this->parent->copyManifest()) {

			// Install failed, rollback changes

			$this->parent->abort(JText::_('Component').' '.JText::_('Install').': '.JText::_('Could not copy setup file'));

			return false;

		}

		return true;

	}



	/**

	 * Custom uninstall method for components

	 *

	 * @access	public

	 * @param	int		$cid	The id of the component to uninstall

	 * @param	int		$clientId	The id of the client (unused)

	 * @return	mixed	Return value for uninstall method in component uninstall file

	 * @since	1.0

	 */

	function uninstall($id, $clientId)

	{

		// Initialize variables

		$db =& $this->parent->getDBO();

		$row	= null;

		$retval	= true;



		// First order of business will be to load the component object table from the database.

		// This should give us the necessary information to proceed.

		$row = & JTable::getInstance('component');

		if ( !$row->load((int) $id) ) {

			JError::raiseWarning(100, JText::_('ERRORUNKOWNEXTENSION'));

			return false;

		}



		// Is the component we are trying to uninstall a core one?

		// Because that is not a good idea...

		if ($row->iscore) {

			JError::raiseWarning(100, JText::_('Component').' '.JText::_('Uninstall').': '.JText::sprintf('WARNCORECOMPONENT', $row->name)."<br />".JText::_('WARNCORECOMPONENT2'));

			return false;

		}



		// Get the admin and site paths for the component

		$this->parent->setPath('extension_administrator', JPath::clean(JPATH_ADMINISTRATOR.DS.'components'.DS.$row->option));

		$this->parent->setPath('extension_site', JPath::clean(JPATH_SITE.DS.'components'.DS.$row->option));



		/**

		 * ---------------------------------------------------------------------------------------------

		 * Manifest Document Setup Section

		 * ---------------------------------------------------------------------------------------------

		 */



		// Find and load the XML install file for the component

		$this->parent->setPath('source', $this->parent->getPath('extension_administrator'));



		// Get the package manifest objecct

		$manifest =& $this->parent->getManifest();

		if (!is_a($manifest, 'JSimpleXML')) {

			// Make sure we delete the folders if no manifest exists

			JFolder::delete($this->parent->getPath('extension_administrator'));

			JFolder::delete($this->parent->getPath('extension_site'));



			// Remove the menu

			$this->_removeAdminMenus($row);



			// Raise a warning

			JError::raiseWarning(100, JText::_('ERRORREMOVEMANUALLY'));



			// Return

			return false;

		}



		// Get the root node of the manifest document

		$this->manifest =& $manifest->document;



		/**

		 * ---------------------------------------------------------------------------------------------

		 * Custom Uninstallation Script Section

		 * ---------------------------------------------------------------------------------------------

		 */



		// Now lets load the uninstall file if there is one and execute the uninstall function if it exists.

		$uninstallfileElement =& $this->manifest->getElementByPath('uninstallfile');

		if (is_a($uninstallfileElement, 'JSimpleXMLElement')) {

			// Element exists, does the file exist?

			if (is_file($this->parent->getPath('extension_administrator').DS.$uninstallfileElement->data())) {

				ob_start();

				ob_implicit_flush(false);

				require_once ($this->parent->getPath('extension_administrator').DS.$uninstallfileElement->data());

				if (function_exists('com_uninstall')) {

					if (com_uninstall() === false) {

						JError::raiseWarning(100, JText::_('Component').' '.JText::_('Uninstall').': '.JText::_('Custom Uninstall script unsuccessful'));

						$retval = false;

					}

				}

				$msg = ob_get_contents();

				ob_end_clean();

				if ($msg != '') {

					$this->parent->set('extension.message', $msg);

				}

			}

		}



		/**

		 * ---------------------------------------------------------------------------------------------

		 * Database Processing Section

		 * ---------------------------------------------------------------------------------------------

		 */



		/*

		 * Let's run the uninstall queries for the component

		 *	If backward compatibility is required - run queries in xml file

		 *	If Joomla 1.5 compatible, with discreet sql files - execute appropriate

		 *	file for utf-8 support or non-utf support

		 */

		$result = $this->parent->parseQueries($this->manifest->getElementByPath('uninstall/queries'));

		if ($result === false) {

			// Install failed, rollback changes

			JError::raiseWarning(100, JText::_('Component').' '.JText::_('Uninstall').': '.JText::_('SQL Error')." ".$db->stderr(true));

			$retval = false;

		} elseif ($result === 0) {

			// no backward compatibility queries found - try for Joomla 1.5 type queries

			// second argument is the utf compatible version attribute

			$utfresult = $this->parent->parseSQLFiles($this->manifest->getElementByPath('uninstall/sql'));

			if ($utfresult === false) {

				// Install failed, rollback changes

				JError::raiseWarning(100, JText::_('Component').' '.JText::_('Uninstall').': '.JText::_('SQLERRORORFILE')." ".$db->stderr(true));

				$retval = false;

			}

		}



		$this->_removeAdminMenus($row);



		/**

		 * ---------------------------------------------------------------------------------------------

		 * Filesystem Processing Section

		 * ---------------------------------------------------------------------------------------------

		 */



		// Let's remove language files and media in the JROOT/images/ folder that are

		// associated with the component we are uninstalling

		$this->parent->removeFiles($this->manifest->getElementByPath('media'));

		$this->parent->removeFiles($this->manifest->getElementByPath('languages'));

		$this->parent->removeFiles($this->manifest->getElementByPath('administration/languages'), 1);



		// Now we need to delete the installation directories.  This is the final step in uninstalling the component.

		if (trim($row->option)) {

			// Delete the component site directory

			if (is_dir($this->parent->getPath('extension_site'))) {

				if (!JFolder::delete($this->parent->getPath('extension_site'))) {

					JError::raiseWarning(100, JText::_('Component').' '.JText::_('Uninstall').': '.JText::_('Unable to remove the component site directory'));

					$retval = false;

				}

			}



			// Delete the component admin directory

			if (is_dir($this->parent->getPath('extension_administrator'))) {

				if (!JFolder::delete($this->parent->getPath('extension_administrator'))) {

					JError::raiseWarning(100, JText::_('Component').' '.JText::_('Uninstall').': '.JText::_('Unable to remove the component admin directory'));

					$retval = false;

				}

			}

			return $retval;

		} else {

			// No component option defined... cannot delete what we don't know about

			JError::raiseWarning(100, 'Component Uninstall: Option field empty, cannot remove files');

			return false;

		}

	}



	/**

	 * Method to build menu database entries for a component

	 *

	 * @access	private

	 * @return	boolean	True if successful

	 * @since	1.5

	 */

	function _buildAdminMenus()

	{

		// Get database connector object

		$db =& $this->parent->getDBO();



		// Initialize variables

		$option = strtolower("com_".str_replace(" ", "", $this->get('name')));



		// If a component exists with this option in the table than we don't need to add menus

		$query = 'SELECT id' .

				' FROM #__components' .

				' WHERE `option` = '.$db->Quote($option);



		$db->setQuery($query);

		$exists = $db->loadResult();



		// Check if menu items exist

		if ($exists) {



			// Don't do anything if overwrite has not been enabled

			if ( ! $this->parent->getOverwrite() ) {

				return true;

			}



			// Remove existing menu items if overwrite has been enabled

			if ( $option ) {



				$sql = 'DELETE FROM #__components WHERE `option` = '.$db->Quote($option);



				$db->setQuery($sql);

				if (!$db->query()) {

					JError::raiseWarning(100, JText::_('Component').' '.JText::_('Install').': '.$db->stderr(true));

				}

			}

		}



		// Ok, now its time to handle the menus.  Start with the component root menu, then handle submenus.

		$menuElement = & $this->adminElement->getElementByPath('menu');

		if (is_a($menuElement, 'JSimpleXMLElement')) {



			$db_name = $menuElement->data();

			$db_link = "option=".$option;

			$db_menuid = 0;

			$db_parent = 0;

			$db_admin_menu_link = "option=".$option;

			$db_admin_menu_alt = $menuElement->data();

			$db_option = $option;

			$db_ordering = 0;

			$db_admin_menu_img = ($menuElement->attributes('img')) ? $menuElement->attributes('img') : 'js/ThemeOffice/component.png';

			$db_iscore = 0;

			$db_params = $this->parent->getParams();

			$db_enabled = 1;



			$query = 'INSERT INTO #__components' .

				' VALUES( "", '.$db->Quote($db_name).', '.$db->Quote($db_link).', '.(int) $db_menuid.',' .

				' '.(int) $db_parent.', '.$db->Quote($db_admin_menu_link).', '.$db->Quote($db_admin_menu_alt).',' .

				' '.$db->Quote($db_option).', '.(int) $db_ordering.', '.$db->Quote($db_admin_menu_img).',' .

				' '.(int) $db_iscore.', '.$db->Quote($db_params).', '.(int) $db_enabled.' )';

			$db->setQuery($query);

			if (!$db->query()) {

				// Install failed, rollback changes

				$this->parent->abort(JText::_('Component').' '.JText::_('Install').': '.$db->stderr(true));

				return false;

			}

			$menuid = $db->insertid();



			/*

			 * Since we have created a menu item, we add it to the installation step stack

			 * so that if we have to rollback the changes we can undo it.

			 */

			$this->parent->pushStep(array ('type' => 'menu', 'id' => $menuid));

		} else {



			/*

			 * No menu element was specified so lets first see if we have an admin menu entry for this component

			 * if we do.. then we obviously don't want to create one -- we'll just attach sub menus to that one.

			 */

			$query = 'SELECT id' .

					' FROM #__components' .

					' WHERE `option` = '.$db->Quote($option) .

					' AND parent = 0';

			$db->setQuery($query);

			$menuid = $db->loadResult();



			if (!$menuid) {

				// No menu entry, lets just enter a component entry to the table.

				$db_name = $this->get('name');

				$db_link = "";

				$db_menuid = 0;

				$db_parent = 0;

				$db_admin_menu_link = "";

				$db_admin_menu_alt = $this->get('name');

				$db_option = $option;

				$db_ordering = 0;

				$db_admin_menu_img = "";

				$db_iscore = 0;

				$db_params = $this->parent->getParams();

				$db_enabled = 1;



				$query = 'INSERT INTO #__components' .

					' VALUES( "", '.$db->Quote($db_name).', '.$db->Quote($db_link).', '.(int) $db_menuid.',' .

					' '.(int) $db_parent.', '.$db->Quote($db_admin_menu_link).', '.$db->Quote($db_admin_menu_alt).',' .

					' '.$db->Quote($db_option).', '.(int) $db_ordering.', '.$db->Quote($db_admin_menu_img).',' .

					' '.(int) $db_iscore.', '.$db->Quote($db_params).', '.(int) $db_enabled.' )';

				$db->setQuery($query);

				if (!$db->query()) {

					// Install failed, rollback changes

					$this->parent->abort(JText::_('Component').' '.JText::_('Install').': '.$db->stderr(true));

					return false;

				}

				$menuid = $db->insertid();



				/*

				 * Since we have created a menu item, we add it to the installation step stack

				 * so that if we have to rollback the changes we can undo it.

				 */

				$this->parent->pushStep(array ('type' => 'menu', 'id' => $menuid));

			}

		}



		/*

		 * Process SubMenus

		 */



		// Initialize submenu ordering value

		$ordering = 0;

		$submenu = $this->adminElement->getElementByPath('submenu');

		if (!is_a($submenu, 'JSimpleXMLElement') || !count($submenu->children())) {

			return true;

		}

		foreach ($submenu->children() as $child)

		{

			if (is_a($child, 'JSimpleXMLElement') && $child->name() == 'menu') {



				$com =& JTable::getInstance('component');

				$com->name = $child->data();

				$com->link = '';

				$com->menuid = 0;

				$com->parent = $menuid;

				$com->iscore = 0;

				$com->admin_menu_alt = $child->data();

				$com->option = $option;

				$com->ordering = $ordering ++;



				// Set the sub menu link

				if ($child->attributes("link")) {

					$com->admin_menu_link = str_replace('&amp;', '&', $child->attributes("link"));

				} else {

					$request = array();

					if ($child->attributes('act')) {

						$request[] = 'act='.$child->attributes('act');

					}

					if ($child->attributes('task')) {

						$request[] = 'task='.$child->attributes('task');

					}

					if ($child->attributes('controller')) {

						$request[] = 'controller='.$child->attributes('controller');

					}

					if ($child->attributes('view')) {

						$request[] = 'view='.$child->attributes('view');

					}

					if ($child->attributes('layout')) {

						$request[] = 'layout='.$child->attributes('layout');

					}

					if ($child->attributes('sub')) {

						$request[] = 'sub='.$child->attributes('sub');

					}

					$qstring = (count($request)) ? '&'.implode('&',$request) : '';

					$com->admin_menu_link = "option=".$option.$qstring;

				}



				// Set the sub menu image

				if ($child->attributes("img")) {

					$com->admin_menu_img = $child->attributes("img");

				} else {

					$com->admin_menu_img = "js/ThemeOffice/component.png";

				}



				// Store the submenu

				if (!$com->store()) {

					// Install failed, rollback changes

					$this->parent->abort(JText::_('Component').' '.JText::_('Install').': '.JText::_('SQL Error')." ".$db->stderr(true));

					return false;

				}



				/*

				 * Since we have created a menu item, we add it to the installation step stack

				 * so that if we have to rollback the changes we can undo it.

				 */

				$this->parent->pushStep(array ('type' => 'menu', 'id' => $com->id));

			}

		}

	}



	/**

	 * Method to remove admin menu references to a component

	 *

	 * @access	private

	 * @param	object	$component	Component table object

	 * @return	boolean	True if successful

	 * @since	1.5

	 */

	function _removeAdminMenus(&$row)

	{

		// Get database connector object

		$db =& $this->parent->getDBO();

		$retval = true;



		// Delete the submenu items

		$sql = 'DELETE ' .

				' FROM #__components ' .

				'WHERE parent = '.(int)$row->id;



		$db->setQuery($sql);

		if (!$db->query()) {

			JError::raiseWarning(100, JText::_('Component').' '.JText::_('Uninstall').': '.$db->stderr(true));

			$retval = false;

		}



		// Next, we will delete the component object

		if (!$row->delete($row->id)) {

			JError::raiseWarning(100, JText::_('Component').' '.JText::_('Uninstall').': '.JText::_('Unable to delete the component from the database'));

			$retval = false;

		}

		return $retval;

	}



	/**

	 * Custom rollback method

	 * 	- Roll back the component menu item

	 *

	 * @access	public

	 * @param	array	$arg	Installation step to rollback

	 * @return	boolean	True on success

	 * @since	1.5

	 */

	function _rollback_menu($arg)

	{

		// Get database connector object

		$db =& $this->parent->getDBO;



		// Remove the entry from the #__components table

		$query = 'DELETE ' .

				' FROM `#__components` ' .

				' WHERE id='.(int)$arg['id'];

		$db->setQuery($query);

		return ($db->query() !== false);

	}

}