Index: units/priorites/priorites_config.php
===================================================================
--- units/priorites/priorites_config.php	(revision 0)
+++ units/priorites/priorites_config.php	(revision 0)
@@ -0,0 +1,30 @@
+<?php
+
+	$config	= Array (
+		'Prefix' => 'priority',
+		'EventHandlerClass' => Array('class' => 'PriorityEventHandler', 'file' => 'priority_eh.php', 'build_event' => 'OnBuild'),
+
+		'QueryString'		=>	Array(
+			1	=>	'prefix',
+			2	=>	'event',
+		),
+
+		'Hooks' => Array(
+			Array(
+				'Mode' => hAFTER,
+				'Conditional' => false,
+				'HookToPrefix' => 'adm',
+				'HookToSpecial' => '*',
+				'HookToEvent' => Array('OnBeforeShutdown'),
+				'DoPrefix' => 'priority',
+				'DoSpecial' => '*',
+				'DoEvent' => 'OnBeforeShutdown',
+				'Conditional' => false,
+			),
+		),
+
+		'PermSection' => Array ('main' => 'custom',),
+
+		'ProcessPrefixes' => Array()
+	);
+?>
\ No newline at end of file
Index: units/priorites/priority_eh.php
===================================================================
--- units/priorites/priority_eh.php	(revision 0)
+++ units/priorites/priority_eh.php	(revision 0)
@@ -0,0 +1,316 @@
+<?php
+
+class PriorityEventHandler extends kDBEventHandler {
+
+	/**
+	 * Allows to override standart permission mapping
+	 *
+	 */
+	function mapPermissions()
+	{
+		parent::mapPermissions();
+		$permissions = Array(
+			'OnRecalculatePriorities'	=>	Array('self' => true),
+		);
+		$this->permMapping = array_merge($this->permMapping, $permissions);
+	}
+
+	function mapEvents()
+	{
+		parent::mapEvents();
+
+		$events_map = Array (
+			'OnMassMoveUp'		=>	'OnChangePriority',
+			'OnMassMoveDown'	=>	'OnChangePriority',
+		);
+
+		$this->eventMethods = array_merge($this->eventMethods, $events_map);
+	}
+
+	/**
+	 * Enter description here...
+	 *
+	 * @param kEvent $event
+	 */
+	function OnAfterConfigRead(&$event)
+	{
+		$hooks = Array(
+			Array(
+				'Mode' => hAFTER,
+				'Conditional' => false,
+				'HookToPrefix' => '',
+				'HookToSpecial' => '*',
+				'HookToEvent' => Array('OnAfterItemLoad', 'OnPreCreate', 'OnListBuild'),
+				'DoPrefix' => 'priority',
+				'DoSpecial' => '*',
+				'DoEvent' => 'OnPreparePriorities',
+				'Conditional' => false,
+			),
+			Array(
+				'Mode' => hBEFORE,
+				'Conditional' => false,
+				'HookToPrefix' => '',
+				'HookToSpecial' => '*',
+				'HookToEvent' => Array('OnPreSaveCreated'),
+				'DoPrefix' => 'priority',
+				'DoSpecial' => '*',
+				'DoEvent' => 'OnPreparePriorities',
+				'Conditional' => false,
+			),
+			Array(
+				'Mode' => hAFTER,
+				'Conditional' => false,
+				'HookToPrefix' => '',
+				'HookToSpecial' => '*',
+				'HookToEvent' => Array('OnPreSave', 'OnPreSaveCreated', 'OnSave', 'OnUpdate'),
+				'DoPrefix' => 'priority',
+				'DoSpecial' => '*',
+				'DoEvent' => 'OnSavePriorityChanges',
+				'Conditional' => false,
+			),
+			Array(
+				'Mode' => hAFTER,
+				'Conditional' => false,
+				'HookToPrefix' => '',
+				'HookToSpecial' => '*',
+				'HookToEvent' => Array('OnSave'),
+				'DoPrefix' => 'priority',
+				'DoSpecial' => '*',
+				'DoEvent' => 'OnSaveItems',
+				'Conditional' => false,
+			),
+			Array(
+				'Mode' => hBEFORE,
+				'Conditional' => false,
+				'HookToPrefix' => '',
+				'HookToSpecial' => '*',
+				'HookToEvent' => Array('OnBeforeItemCreate'),
+				'DoPrefix' => 'priority',
+				'DoSpecial' => '*',
+				'DoEvent' => 'OnItemCreate',
+				'Conditional' => false,
+			),
+			Array(
+				'Mode' => hBEFORE,
+				'Conditional' => false,
+				'HookToPrefix' => '',
+				'HookToSpecial' => '*',
+				'HookToEvent' => Array('OnAfterItemDelete'),
+				'DoPrefix' => 'priority',
+				'DoSpecial' => '*',
+				'DoEvent' => 'OnItemDelete',
+				'Conditional' => false,
+			)
+		);
+
+		$prefixes = $this->Application->getUnitOption($event->Prefix, 'ProcessPrefixes');
+		foreach ($prefixes as $prefix) {
+			foreach ($hooks as $hook) {
+				if (!is_array($hook['HookToEvent'])) {
+					$hook['HookToEvent'] = Array($hook['HookToEvent']);
+				}
+				foreach ($hook['HookToEvent'] as $hook_event) {
+					$this->Application->registerHook(
+						$prefix,
+						$hook['HookToSpecial'],
+						$hook_event,
+						$hook['Mode'],
+						$event->Prefix,
+						$hook['DoSpecial'],
+						$hook['DoEvent'],
+						$hook['Conditional']
+					);
+				}
+			}
+		}
+	}
+
+	/**
+	 * Should be hooked to OnAfterItemLoad, OnPreSaveCreated (why latter?)
+	 *
+	 * @param kEvent $event
+	 */
+	function OnPreparePriorities(&$event)
+	{
+		if (!$this->Application->IsAdmin()) return; 
+		$priority_helper =& $this->Application->recallObject('PriorityHelper');
+		/* @var $priority_helper kPriorityHelper */
+
+		$is_new = $event->MasterEvent->Name == 'OnPreCreate' || $event->MasterEvent->Name == 'OnPreSaveCreated';
+		$priority_helper->preparePriorities($event->MasterEvent, $is_new);
+	}
+
+	/**
+	 * Enter description here...
+	 *
+	 * @param kEvent $event
+	 */
+	function OnSavePriorityChanges(&$event)
+	{
+		$object =& $event->MasterEvent->getObject();
+
+		$tmp = $this->Application->RecallVar('priority_changes'.$this->Application->GetVar('m_wid'));
+		$changes = $tmp ? unserialize($tmp) : array();
+
+		if (!isset($changes[$object->GetID()])) {
+			$changes[$object->GetId()]['old'] = $object->GetID() == 0 ? 'new' : $object->GetDBField('OldPriority');
+		}
+
+		if ($changes[$object->GetId()]['old'] == $object->GetDBField('Priority')) return ;
+		$changes[$object->GetId()]['new'] = $object->GetDBField('Priority');
+
+		$this->Application->StoreVar('priority_changes'.$this->Application->GetVar('m_wid'), serialize($changes));
+	}
+
+	/**
+	 * Enter description here...
+	 *
+	 * @param kEvent $event
+	 */
+	function OnItemDelete(&$event)
+	{
+		// just store the prefix in which the items were deleted
+		$del = $this->Application->RecallVar('priority_deleted'.$this->Application->GetVar('m_wid'));
+		$del = $del ? unserialize($del) : array();
+		$del[] = $event->MasterEvent->Prefix;
+		$this->Application->StoreVar('priority_deleted'.$this->Application->GetVar('m_wid'), serialize(array_unique($del)));
+	}
+
+	/**
+	 * Called before script shut-down and recalculate all deleted prefixes, to avoid recalculation on each deleted item
+	 *
+	 * @param kEvent $event
+	 */
+	function OnBeforeShutDown(&$event)
+	{
+		$del = $this->Application->RecallVar('priority_deleted'.$this->Application->GetVar('m_wid'));
+		$del = $del ? unserialize($del) : array();
+
+		$priority_helper =& $this->Application->recallObject('PriorityHelper');
+		/* @var $priority_helper kPriorityHelper */
+
+		foreach ($del as $prefix) {
+			$dummy_event = new kEvent( array('prefix'=>$prefix, 'name'=>'Dummy' ) );
+
+			$ids = $priority_helper->recalculatePriorities($dummy_event);
+			if ($ids) {
+				$my_event = new kEvent('api:OnAddToQueue');
+				$my_event->setEventParam('prefix', $prefix);
+				$my_event->setEventParam('ids', array_unique($ids));
+				$this->Application->HandleEvent($my_event);
+			}
+		}
+		$this->Application->RemoveVar('priority_deleted'.$this->Application->GetVar('m_wid'));
+	}
+
+
+	/**
+	 * Enter description here...
+	 *
+	 * @param kEvent $event
+	 */
+	function OnSaveItems(&$event)
+	{
+		$tmp = $this->Application->RecallVar('priority_changes'.$this->Application->GetVar('m_wid'));
+		$changes = $tmp ? unserialize($tmp) : array();
+
+		$priority_helper =& $this->Application->recallObject('PriorityHelper');
+		/* @var $priority_helper kPriorityHelper */
+
+		$ids = $priority_helper->updatePriorities($event->MasterEvent, $changes, $event->MasterEvent->getEventParam('ids'));
+		if ($ids) {
+			$my_event = new kEvent('api:OnAddToQueue');
+			$my_event->setEventParam('prefix', $event->MasterEvent->Prefix);
+			$my_event->setEventParam('ids', array_unique($ids));
+			$this->Application->HandleEvent($my_event);
+		}
+	}
+
+	function OnItemCreate(&$event)
+	{
+		$obj =& $event->MasterEvent->getObject();
+		if ($obj->GetDBField('Priority') == 0) {
+			$priority_helper =& $this->Application->recallObject('PriorityHelper');
+			/* @var $priority_helper kPriorityHelper */
+
+			$priority_helper->preparePriorities($event->MasterEvent, true);
+		}
+	}
+
+	/**
+	 * Processes OnMassMoveUp, OnMassMoveDown events
+	 *
+	 * @param kEvent $event
+	 */
+	function OnChangePriority(&$event)
+	{
+		$prefix = $this->Application->GetVar('priority_prefix');
+		$dummy_event = new kEvent( array('prefix'=>$prefix, 'name'=>'Dummy' ) );
+
+		$ids = $this->StoreSelectedIDs($dummy_event);
+
+		if ($ids) {
+			$id_field = $this->Application->getUnitOption($prefix, 'IDField');
+			$table_name = $this->Application->getUnitOption($prefix, 'TableName');
+//			$parent_id = $this->Application->GetVar('m_cat_id');
+
+			$sql = 'SELECT Priority, '.$id_field.'
+					FROM '.$table_name.'
+					WHERE '.$id_field.' IN ('.implode(',', $ids).') ORDER BY Priority DESC';
+			$priorities = $this->Conn->GetCol($sql, $id_field);
+			$min_priorirty = $this->Conn->GetOne('SELECT IFNULL(MIN(Priority),-1) FROM '.$table_name);
+
+			$priority_helper =& $this->Application->recallObject('PriorityHelper');
+			/* @var $priority_helper kPriorityHelper */
+
+			foreach ($ids as $id) {
+				$new_priority = $priorities[$id] + ($event->Name == 'OnMassMoveUp' ? +1 : -1);
+				if ($new_priority > -1 || $new_priority < $min_priorirty) {
+					continue;
+				}
+
+				$changes = Array (
+					$id	=>	Array ('old' => $priorities[$id], 'new' => $new_priority),
+				);
+
+				$sql = 'UPDATE '.$table_name.'
+						SET Priority = '.$new_priority.'
+						WHERE '.$id_field.' = '.$id;
+				$this->Conn->Query($sql);
+
+				$ids = $priority_helper->updatePriorities($dummy_event, $changes, Array ($id => $id));
+				if ($ids) {
+					$my_event = new kEvent('api:OnAddToQueue');
+					$my_event->setEventParam('prefix', $prefix);
+					$my_event->setEventParam('ids', array_unique($ids));
+					$this->Application->HandleEvent($my_event);
+				}
+			}
+		}
+
+		$this->clearSelectedIDs($dummy_event);
+	}
+
+	/**
+	 * Completely recalculates priorities in current category
+	 *
+	 * @param kEvent $event
+	 */
+	function OnRecalculatePriorities(&$event)
+	{
+		$priority_helper =& $this->Application->recallObject('PriorityHelper');
+		/* @var $priority_helper kPriorityHelper */
+
+		$prefix = $this->Application->GetVar('priority_prefix');
+		$dummy_event = new kEvent( array('prefix'=>$prefix, 'name'=>'Dummy' ) );
+
+		$ids = $priority_helper->recalculatePriorities($dummy_event);
+		if ($ids) {
+			$my_event = new kEvent('api:OnAddToQueue');
+			$my_event->setEventParam('prefix', $prefix);
+			$my_event->setEventParam('ids', array_unique($ids));
+			$this->Application->HandleEvent($my_event);
+		}
+	}
+
+}
\ No newline at end of file