class.ilLuceneSearchResultFilter.php

Go to the documentation of this file.

<?php
/*
        +-----------------------------------------------------------------------------+
        | ILIAS open source                                                           |
        +-----------------------------------------------------------------------------+
        | Copyright (c) 1998-2006 ILIAS open source, University of Cologne            |
        |                                                                             |
        | This program is free software; you can redistribute it and/or               |
        | modify it under the terms of the GNU General Public License                 |
        | as published by the Free Software Foundation; either version 2              |
        | of the License, or (at your option) any later version.                      |
        |                                                                             |
        | This program is distributed in the hope that it will be useful,             |
        | but WITHOUT ANY WARRANTY; without even the implied warranty of              |
        | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               |
        | GNU General Public License for more details.                                |
        |                                                                             |
        | You should have received a copy of the GNU General Public License           |
        | along with this program; if not, write to the Free Software                 |
        | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. |
        +-----------------------------------------------------------------------------+
*/
 
class ilLuceneSearchResultFilter
{
        protected static $instance = null;
        
        protected $user_id = null;
        protected $result = array();
        protected $checked = array();
        protected $settings;
        protected $cache;
        protected $required_permission = 'visible';
        protected $limit_reached = false;
        protected $offset = 0;
        
        protected $filters = array();
 
 
        protected function __construct($a_user_id)
        {
                $this->user_id = $a_user_id;
                $this->settings = ilSearchSettings::getInstance();
 
                include_once('Services/Search/classes/class.ilUserSearchCache.php');
                $this->cache = ilUserSearchCache::_getInstance($this->getUserId());
                
                $this->offset = $this->settings->getMaxHits() * ($this->cache->getResultPageNumber() - 1);
        }
        
        public static function getInstance($a_user_id)
        {
                if(self::$instance == null)
                {
                        return self::$instance = new ilLuceneSearchResultFilter($a_user_id);
                }
                return self::$instance;
        }
        
        public function addFilter(ilLuceneResultFilter $filter)
        {
                $this->filters[] = $filter;
        }
        
        public function setCandidates($a_ids)
        {
                $this->result = $a_ids;
        }
        
        public function getCandidates()
        {
                return $this->result ? $this->result : array();
        }
        
        public function getUserId()
        {
                return $this->user_id;
        }
        
        public function getRequiredPermission()
        {
                return $this->required_permission;
        }
        
        public function isLimitReached()
        {
                return (bool) $this->limit_reached;
        }
        
        public function getResultIds()
        {
                return $this->checked ? $this->checked : array();
        }
        
        public function getResultObjIds()
        {
                foreach($this->checked as $obj_id)
                {
                        $obj_ids[] = $obj_id;
                }
                return $obj_ids ? $obj_ids : array();
        }
        
        public function getResults()
        {
                return $this->checked ? $this->checked : array();
        }
        
        public function getMaxHits()
        {
                return $this->settings->getMaxHits();            
        }
        
        public function loadFromDb()
        {
                $this->checked = $this->cache->getResults();
        }
        
        public function filter()
        {
                global $ilAccess,$tree;
 
                // get ref_ids and check access
                $counter = 0;
                $offset_counter = 0;
                
                foreach($this->getCandidates() as $obj_id)
                {
                        // Check referenced objects
                        foreach(ilObject::_getAllReferences($obj_id) as $ref_id)
                        {
                                // Check filter
                                if(!$this->checkFilter($ref_id))
                                {
                                        $this->cache->appendToFailed($ref_id);
                                        continue;
                                }
 
                                // Access failed by prior check
                                if($this->cache->isFailed($ref_id))
                                {
                                        continue;
                                }
                                // Offset check
                                if($this->cache->isChecked($ref_id) and !$this->isOffsetReached($offset_counter))
                                {
                                        ilLoggerFactory::getLogger('src')->debug('Result was checked');
                                        $offset_counter++;
                                        break;
                                }
                                
                                // RBAC check
                                if($ilAccess->checkAccessOfUser($this->getUserId(),
                                                                                                          $this->getRequiredPermission(),
                                                                                                          '',
                                                                                                          $ref_id,
                                                                                                          '',
                                                                                                          $obj_id))
                                {
                                        ++$counter;
                                        $offset_counter++;
                                        $this->append($ref_id,$obj_id);
                                        $this->cache->appendToChecked($ref_id,$obj_id);
                                        break;
                                }
                                else
                                {
                                        $this->cache->appendToFailed($ref_id);
                                }
                        }
                        if($counter >= $this->settings->getMaxHits())
                        {
                                $this->limit_reached = true;
                                $this->cache->setResults($this->getResultIds());
                                $this->cache->save();
                                return false;
                        }
                }
                $this->cache->setResults($this->getResultIds());
                $this->cache->save();
                return true;
        }
        
        protected function checkFilter($a_ref_id)
        {
                foreach($this->filters as $filter)
                {
                        if(!$filter->filter($a_ref_id))
                        {
                                return false;
                        }
                }
                return true;
        }
        
        protected function append($a_ref_id,$a_obj_id)
        {
                $this->checked[$a_ref_id] = $a_obj_id;
        }
        
        protected function isOffsetReached($a_current_nr)
        {
                return $a_current_nr < $this->offset ? false : true;
        }
}
?>