<?php



// +----------------------------------------------------------------------+

// | Copyright (c) 2001 Christchurch College of Education				  |

// +------------------------------------------------------------------------+

// | This file is part of Interact.											|

// |																	  	| 

// | 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 (version 2)							 	|

// |																	  	|	 

// | 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, you can view it at				  	|

// | http://www.opensource.org/licenses/gpl-license.php				   		|

// +------------------------------------------------------------------------+



/**

* Tag  functions

*

* Contains any functions related to adding, modifying, displaying tags

*

* @package Common

* @author Glen Davies <glen.davies@cce.ac.nz>

* @copyright Christchurch College of Education 2005 

* @version $Id: tags.inc.php,v 1.14 2007/05/09 03:02:51 glendavies Exp $

* 

*/



/**

* A class that contains methods related to tag functions 

* 

* This class is part of the Interact online learning and collaboration platform. 

* It contains methods for retrieving,displying and modifying tags

* 

* @package Tags

* @author Glen Davies <glen.davies@cce.ac.nz>

*/



class InteractTags {



	

	/**

	* A method of class Tags to add a new tag, first checks to see if tag already exists

	* @param  string $tag_string a string of tags separated by character other than space

	* @return array $tag_array an array of individual tags 

	*/

	

	function splitTags($tag_string) {

	

		return preg_split("/,|;/", $tag_string);

		

	} //end splitTags()

	

	/**

	* A method of class Tags to add a new tag, first checks to see if tag already exists

	* @param  string $text text string of tag to add

	* @return int $tag_key key of new tag 

	*/

	

	function addTag($text) {

	

		global $CONN, $CONFIG;



		//first see if tag already exists

		$text = strip_tags($text);

		$tag_key = $this->getTagKey($text);

		if ($tag_key!=false || empty($text)) {

			return $tag_key;	

		} else {

			$CONN->Execute("INSERT INTO {$CONFIG['DB_PREFIX']}tags(text) VALUES ('$text')");

			

			return $CONN->Insert_ID();

		}	

		

	} //end addTag()



	/**

	* A method of class Tags to get tag_key for an existing tag

	* @param  string $text text string to get tag key for

	* @return int $tag_key of tag, or false if tag does not exist 

	*/

	

	function getTagKey($text) {

	

		global $CONN, $CONFIG;



		

		$tag_key = $CONN->GetOne("SELECT tag_key FROM {$CONFIG['DB_PREFIX']}tags WHERE text='$text'");

		return $tag_key;	

		

	} //end getTagKey()

	/**

	* A method of class Tags to get tag_text for an existing tag

	* @param  int $tag_key text key to get tag key for

	* @return string $text of tag, or false if tag does not exist 

	*/

	

	function getTagText($tag_key) {

	

		global $CONN, $CONFIG;

		

		return $CONN->GetOne("SELECT text FROM {$CONFIG['DB_PREFIX']}tags WHERE tag_key='$tag_key'");

		

	} //end getTagKey()	



	/**

	* A method of class Tags to get tag_key for an existing tag

	* @param  int $tag_key tag_key of tag to add link for

	* @param  int $module_key key of module to add tage for

	* @param  int $user_key key of user to add tag for

	* @param  int $entry_key key of individual module entry to add tag for

	* @param  int $url_key key of url to add tag for * 

	* @return true  

	*/

	

	function addTaglink($tag_key, $module_key=0, $user_key=0, $entry_key=0, $url_key=0) {

	

		global $CONN, $CONFIG;



		$date_added = $CONN->DBDate(date('Y-m-d H:i:s'));

		$CONN->Execute("INSERT INTO {$CONFIG['DB_PREFIX']}tag_links(tag_key, module_key, user_key, entry_key, url_key, date_added) VALUES ('$tag_key', '$module_key', '$user_key', '$entry_key', '$url_key', $date_added)");

		return true;	

		

	} //end addTaglink()

	

	/**

	* A method of class Tags to add a string of tags

	* @param  int $tag_string string of tags to add

	* @param  int $module_key key of module to add tage for

	* @param  int $user_key key of user to add tag for

	* @param  int $entry_key key of individual module entry to add tag for	

	* @param  int $url_key key of url to add tag for 

	* @return true  

	*/

	

	function addTags($tag_string, $module_key=0, $user_key=0, $entry_key=0, $url_key=0) {

	

		global $CONN, $CONFIG;



		$tag_array = $this->splitTags($tag_string);

		if (is_array($tag_array)) {

			$count = count($tag_array);

			for ($i=0; $i<$count; $i++) {

				$tag_key = $this->addTag(trim(strtolower($tag_array[$i])));

				$this->addTaglink($tag_key, $module_key, $user_key, $entry_key, $url_key);

			}	

		}

		return true;	

		

	} //end addTags()

	

	/**

	* A method of class Tags to get an array of tags for given user or module

	* @param  int $module_key key of module to get tags for

	* @param  int $user_key key of user to get tags for

	* @param  int $entry_key key of individual module entry to get tags for

	* @return true  

	*/

	

	function getTags($module_key='', $user_key='', $entry_key='', $url_key='') {

	

		global $CONN, $CONFIG;



		if (isset($module_key) && $module_key!='') {

			$module_limit = "AND module_key='$module_key'";	

		} else {

			$module_limit = '';

		}

		if (isset($user_key) && $user_key!='') {

			$user_limit = "AND user_key='$user_key'";	

		} else {

			$user_limit = '';

		}

		if (isset($entry_key) && $entry_key!='') {

			$entry_limit = "AND entry_key='$entry_key'";	

		} else {

			$entry_limit = '';

		}

		if (isset($url_key) && $url_key!='') {

			$url_limit = "AND url_key='$url_key'";	

		} else {

			$url_limit = '';

		}

		$CONN->SetFetchMode('ADODB_FETCH_ASSOC');



		

		return $CONN->GetArray("SELECT {$CONFIG['DB_PREFIX']}tags.tag_key, text, COUNT(*) as count FROM {$CONFIG['DB_PREFIX']}tags, {$CONFIG['DB_PREFIX']}tag_links WHERE {$CONFIG['DB_PREFIX']}tags.tag_key={$CONFIG['DB_PREFIX']}tag_links.tag_key $module_limit $user_limit $entry_limit $url_limit GROUP BY {$CONFIG['DB_PREFIX']}tags.tag_key ORDER BY count DESC");

		

		$CONN->SetFetchMode('ADODB_FETCH_NUM');

				

	} //end getTags()



}

?>