[4.0] Global Delete Trash - New Feature

It has been requested several times that there was a single place where you could go and "empty the trash" for all components.

This new component is based on com_checkin

At this stage
[ ] I am sure the code in the model can be improved
[ ] What should the default permissions be or should it be hard coded restricted to super users only like joomlaupdate is

### testing
Apply patch and then discover the component
You will then find it in the Maintenance section of the system dashboard

administrator/components/com_trash/Controller/DisplayController.php

@@ -0,0 +1,122 @@
+<?php
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_trash
+ *
+ * @copyright   Copyright (C) 2005 - 2019 Open Source Matters, Inc. All rights reserved.
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\Component\Trash\Administrator\Controller;
+
+defined('_JEXEC') or die;
+
+use Joomla\CMS\Factory;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\MVC\Controller\BaseController;
+use Joomla\CMS\Response\JsonResponse;
+
+/**
+ * Trash Controller
+ *
+ * @since  __DEPLOY_VERSION__
+ */
+class DisplayController extends BaseController
+{
+	/**
+	 * The default view.
+	 *
+	 * @var    string
+	 * @since  __DEPLOY_VERSION__
+	 */
+	protected $default_view = 'trash';
+
+	/**
+	 * Method to display a view.
+	 *
+	 * @param   boolean  $cachable   If true, the view output will be cached
+	 * @param   array    $urlparams  An array of safe URL parameters and their variable types, for valid values see {@link \JFilterInput::clean()}.
+	 *
+	 * @return  static  A \JControllerLegacy object to support chaining.
+	 */
+	public function display($cachable = false, $urlparams = array())
+	{
+		return parent::display();
+	}
+
+	/**
+	 * Trash a list of items.
+	 *
+	 * @return  void
+	 */
+	public function trash()
+	{
+		// Check for request forgeries
+		$this->checkToken();
+
+		$ids = $this->input->get('cid', array(), 'array');
+
+		if (empty($ids))
+		{
+			$this->app->enqueueMessage(Text::_('JLIB_HTML_PLEASE_MAKE_A_SELECTION_FROM_THE_LIST'), 'warning');
+		}
+		else
+		{
+			// Get the model.
+			/** @var \Joomla\Component\Trash\Administrator\Model\TrashModel $model */
+			$model = $this->getModel('Trash');
+
+			// Trash the items.
+			$this->setMessage(Text::plural('COM_TRASH_N_ITEMS_DELETED', $model->trash($ids)));
+		}
+
+		$this->setRedirect('index.php?option=com_trash');
+	}
+
+	/**
+	 * Provide the data for a badge in a menu item via JSON
+	 *
+	 * @return  void
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function getMenuBadgeData()
+	{
+		if (!Factory::getUser()->authorise('core.admin', 'com_trash'))
+		{
+			throw new \Exception(Text::_('JGLOBAL_AUTH_ACCESS_DENIED'));
+		}
+
+		$model = $this->getModel('Trash');
+
+		$amount = (int) count($model->getItems());
+
+		echo new JsonResponse($amount);
+	}
+
+	/**
+	 * Method to get the number of trashed items
+	 *
+	 * @return  void
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function getQuickiconContent()
+	{
+		if (!Factory::getUser()->authorise('core.admin', 'com_trash'))
+		{
+			throw new \Exception(Text::_('JGLOBAL_AUTH_ACCESS_DENIED'));
+		}
+
+		$model = $this->getModel('Trash');
+
+		$amount = (int) count($model->getItems());
+
+		$result = [];
+
+		$result['amount'] = $amount;
+		$result['sronly'] = Text::plural('COM_TRASH_N_QUICKICON_SRONLY', $amount);
+
+		echo new JsonResponse($result);
+	}
+}

administrator/components/com_trash/Model/TrashModel.php

@@ -0,0 +1,270 @@
+<?php
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_trash
+ *
+ * @copyright   Copyright (C) 2005 - 2019 Open Source Matters, Inc. All rights reserved.
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\Component\Trash\Administrator\Model;
+
+defined('_JEXEC') or die;
+
+use Joomla\CMS\Factory;
+use Joomla\CMS\MVC\Factory\MVCFactoryInterface;
+use Joomla\CMS\MVC\Model\ListModel;
+
+/**
+ * Trash Model
+ *
+ * @since  __DEPLOY_VERSION__
+ */
+class TrashModel extends ListModel
+{
+	/**
+	 * Count of the total items in trashed state
+	 *
+	 * @var  integer
+	 */
+	protected $total;
+
+	/**
+	 * Constructor.
+	 *
+	 * @param   array                $config   An optional associative array of configuration settings.
+	 * @param   MVCFactoryInterface  $factory  The factory.
+	 *
+	 * @see     \Joomla\CMS\MVC\Model\BaseDatabaseModel
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function __construct($config = array(), MVCFactoryInterface $factory = null)
+	{
+		if (empty($config['filter_fields']))
+		{
+			$config['filter_fields'] = array(
+				'table',
+				'count',
+			);
+		}
+
+		parent::__construct($config, $factory);
+	}
+
+	/**
+	 * Method to auto-populate the model state.
+	 *
+	 * Note: Calling getState in this method will result in recursion.
+	 *
+	 * @param   string  $ordering   An optional ordering field.
+	 * @param   string  $direction  An optional direction (asc|desc).
+	 *
+	 * @return  void
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	protected function populateState($ordering = 'table', $direction = 'asc')
+	{
+		// List state information.
+		parent::populateState($ordering, $direction);
+	}
+
+	/**
+	 * Deletes items in requested tables
+	 *
+	 * @param   array  $ids  An array of table names. Optional.
+	 *
+	 * @return  mixed  The database results or 0
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function trash($ids = array())
+	{
+		$db = $this->getDbo();
+
+		if (!is_array($ids))
+		{
+			return 0;
+		}
+
+		// This int will hold the trashed item count.
+		$results = 0;
+
+		$app = Factory::getApplication();
+
+		foreach ($ids as $tn)
+		{
+			// Make sure we get the right tables based on prefix.
+			if (stripos($tn, $app->get('dbprefix')) !== 0)
+			{
+				continue;
+			}
+
+			// Set the column name for the where clause
+			$fields = $db->getTableColumns($tn);
+
+			if (isset($fields['state']))
+			{
+				$column = 'state';
+			}
+			elseif (isset($fields['published']))
+			{
+				$column = 'published';
+			}
+
+			$query = $db->getQuery(true)
+					->delete($db->quoteName($tn))
+					->where( $column . ' = -2');
+
+			$db->setQuery($query);
+
+			if ($db->execute())
+			{
+				$results = $results + $db->getAffectedRows();
+				$app->triggerEvent('onAfterTrash', array($tn));
+			}
+		}
+
+		return $results;
+	}
+
+	/**
+	 * Get total of tables
+	 *
+	 * @return  integer  Total to trash tables
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function getTotal()
+	{
+		if (!isset($this->total))
+		{
+			$this->getItems();
+		}
+
+		return $this->total;
+	}
+
+	/**
+	 * Get tables
+	 *
+	 * @return  array  Table names as keys and item count as values.
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function getItems()
+	{
+		if (!isset($this->items))
+		{
+			$db     = $this->getDbo();
+			$tables = $db->getTableList();
+
+			// This array will hold table name as key and item count as value.
+			$results = array();
+
+			foreach ($tables as $i => $tn)
+			{
+				// Make sure we get the right tables based on prefix.
+				if (stripos($tn, Factory::getApplication()->get('dbprefix')) !== 0)
+				{
+					unset($tables[$i]);
+					continue;
+				}
+
+				if ($this->getState('filter.search') && stripos($tn, $this->getState('filter.search')) === false)
+				{
+					unset($tables[$i]);
+					continue;
+				}
+
+				$fields = $db->getTableColumns($tn);
+
+				// only work with the tables that have a state or published column
+				if (!(isset($fields['state'])) && !(isset($fields['published'])))
+				{
+					unset($tables[$i]);
+					continue;
+				}
+
+			}
+
+			foreach ($tables as $tn)
+			{
+				// Set the column name for the where clause
+				$fields = $db->getTableColumns($tn);
+
+				if (isset($fields['state']))
+				{
+					$column = 'state';
+				}
+				elseif (isset($fields['published']))
+				{
+					$column = 'published';
+				}
+
+				$query = $db->getQuery(true)
+					->select('COUNT(*)')
+					->from($db->quoteName($tn))
+					->where( $column . ' = -2');
+
+				$db->setQuery($query);
+
+				if ($db->execute())
+				{
+					$results[$tn] = $db->loadResult();
+
+					// Show only tables with items to trash.
+					if ((int) $results[$tn] === 0)
+					{
+						unset($results[$tn]);
+					}
+				}
+				else
+				{
+					continue;
+				}
+			}
+
+			$this->total = count($results);
+
+			// Order items by table
+			if ($this->getState('list.ordering') == 'table')
+			{
+				if (strtolower($this->getState('list.direction')) == 'asc')
+				{
+					ksort($results);
+				}
+				else
+				{
+					krsort($results);
+				}
+			}
+			// Order items by number of items
+			else
+			{
+				if (strtolower($this->getState('list.direction')) == 'asc')
+				{
+					asort($results);
+				}
+				else
+				{
+					arsort($results);
+				}
+			}
+
+			// Pagination
+			$limit = (int) $this->getState('list.limit');
+
+			if ($limit !== 0)
+			{
+				$this->items = array_slice($results, $this->getState('list.start'), $limit);
+			}
+			else
+			{
+				$this->items = $results;
+			}
+		}
+
+		return $this->items;
+	}
+}