/protected/modules/tag/components/ETaggableBehavior.php

<?php
/**
 * ETaggableBehavior class file.
 *
 * @author Alexander Makarov
 * @link http://code.google.com/p/yiiext/
 */
/**
 * Provides tagging ability for a model.
 *
 * @version 1.5
 * @package yiiext.behaviors.model.taggable
 */
class ETaggableBehavior extends CActiveRecordBehavior {
	/**
	 * @var string tags table name.
	 */
	public $tagTable = 'tag';
	/**
	 * @var string tag table field that contains tag name.
	 */
	public $tagTableName = 'name';
	/**
	 * @var string tag table PK name.
	 */
	public $tagTablePk = 'id';
	/**
	 * @var string tag to Model binding table name.
	 * Defaults to `{model table name}Tag`.
	 */
	public $tagBindingTable = 'page_nm_tag';
	/**
	 * @var string binding table tagId name.
	 */
	public $tagBindingTableTagId = 'tag_id';
	/**
	 * @var string|null tag table count field. If null don't uses database.
	 */
	public $tagTableCount;
	/**
	 * @var string binding table model FK name.
	 * Defaults to `{model table name with first lowercased letter}Id`.
	 */
	public $modelTableFk = 'page_id';
	/**
	 * @var boolean which create tags automatically or throw exception if tag does not exist.
	 */
	public $createTagsAutomatically = true;
	/**
	 * @var string|boolean caching component Id. If false don't use cache.
	 * Defaults to false.
	 */
	public $cacheID = 'cache';

	private $tags = array();
	private $originalTags = array();
	/**
	 * @var CDbConnection
	 */
	private $_conn;
	/**
	 * @var CCache
	 */
	protected $cache;
	/**
	 * @var array|CDbCriteria default scope criteria. Used as filter in find, load, create or update tags.
	 */
	public $scope = array();
	/**
	 * @var array these values are added on inserting tag into DB.
	 */
	public $insertValues = array();
	/**
	 * @var CDbCriteria|null scope CDbCriteria cache.
	 */
	private $scopeCriteria = null;
        
        /**
	 * Get DB connection.
	 * @return CDbConnection
	 */
	protected function getConnection() {
		if(!isset($this->_conn)){
			$this->_conn = $this->getOwner()->dbConnection;
		}
		return $this->_conn;
	}
	/**
	 * @throws CException
	 * @param CComponent $owner
	 * @return void
	 */
	public function attach($owner) {
		// Prepare cache component
		if($this->cacheID!==false)
			$this->cache = Yii::app()->getComponent($this->cacheID);
		if(!($this->cache instanceof ICache)){
			// If not set cache component, use dummy cache.
			$this->cache = new CDummyCache;
		}

		parent::attach($owner);
	}
	/**
	 * Allows to print object.
	 * @return string
	 */
	public function toString() {
		$this->loadTags();
		return implode(', ', $this->tags);
	}
	/**
	 * Get tag binding table name.
	 * @access private
	 * @return string
	 */
	private function getTagBindingTableName() {
		if($this->tagBindingTable === null){
			$this->tagBindingTable = $this->getOwner()->tableName().'Tag';
		}
		return $this->tagBindingTable;
	}
	/**
	 * Get model table FK name.
	 * @access private
	 * @return string
	 */
	private function getModelTableFkName() {
		if($this->modelTableFk === null){
			$tableName = $this->getOwner()->tableName();
			$tableName[0] = strtolower($tableName[0]);
			$this->modelTableFk = $tableName.'Id';
		}
		return $this->modelTableFk;
	}
	/**
	 * Set one or more tags.
	 * @param string|array $tags
	 * @return void
	 */
	public function setTags($tags) {
		$tags = $this->toTagsArray($tags);
		$this->tags = array_unique($tags);

		return $this->getOwner();
	}
	/**
	 * Add one or more tags.
	 * @param string|array $tags
	 * @return void
	 */
	public function addTags($tags) {
		$this->loadTags();

		$tags = $this->toTagsArray($tags);
		$this->tags = array_unique(array_merge($this->tags, $tags));

		return $this->getOwner();
	}
	/**
	 * Alias of {@link addTags()}.
	 * @param string|array $tags
	 * @return void
	 */
	public function addTag($tags) {
		return $this->addTags($tags);
	}
	/**
	 * Remove one or more tags.
	 * @param string|array $tags
	 * @return void
	 */
	public function removeTags($tags) {
		$this->loadTags();

		$tags = $this->toTagsArray($tags);
		$this->tags = array_diff($this->tags, $tags);

		return $this->getOwner();
	}
	/**
	 * Alias of {@link removeTags}.
	 * @param string|array $tags
	 * @return void
	 */
	public function removeTag($tags) {
		return $this->removeTags($tags);
	}
	/**
	 * Remove all tags.
	 * @return void
	 */
	public function removeAllTags() {
		$this->loadTags();
		$this->tags = array();
		return $this->getOwner();
	}
	/**
	 * Get default scope criteria.
	 * @return CDbCriteria
	 */
	protected function getScopeCriteria() {
		if(!$this->scopeCriteria){

			$scope = $this->scope;

			if(is_array($this->scope) && !empty($this->scope)){
				$scope = new CDbCriteria($this->scope);
			}
			if($scope instanceof CDbCriteria){
				$this->scopeCriteria = $scope;
			}
		}
		return $this->scopeCriteria;
	}
	/**
	 * Get tags.
	 * @return array
	 */
	public function getTags() {
		$this->loadTags();
		return $this->tags;
	}
	/**
	 * Get current model's tags with counts.
	 * @todo: quick implementation, rewrite!
	 * @param CDbCriteria $criteria
	 * @return array
	 */
	public function getTagsWithModelsCount($criteria = null) {
		if(!($tags = $this->cache->get($this->getCacheKey().'WithModelsCount'))){

			$builder = $this->getConnection()->getCommandBuilder();

			if($this->tagTableCount !== null){
				$findCriteria = new CDbCriteria(array(
					'select' => "t.{$this->tagTableName} as `name`, t.{$this->tagTableCount} as `count` ",
					'join' => "INNER JOIN {$this->getTagBindingTableName()} et on t.{$this->tagTablePk} = et.{$this->tagBindingTableTagId} ",
					'condition' => "et.{$this->getModelTableFkName()} = :ownerid ",
					'params' => array(
						':ownerid' => $this->getOwner()->primaryKey,
					)
				));
			} else{
				$findCriteria = new CDbCriteria(array(
					'select' => "t.{$this->tagTableName} as `name`, count(*) as `count` ",
					'join' => "INNER JOIN {$this->getTagBindingTableName()} et on t.{$this->tagTablePk} = et.{$this->tagBindingTableTagId} ",
					'condition' => "et.{$this->getModelTableFkName()} = :ownerid ",
					'group' => 't.'.$this->tagTablePk,
					'params' => array(
						':ownerid' => $this->getOwner()->primaryKey,
					)
				));
			}

			if($criteria){
				$findCriteria->mergeWith($criteria);
			}

			$tags = $builder->createFindCommand(
				$this->tagTable,
				$findCriteria
			)->queryAll();

			$this->cache->set($this->getCacheKey().'WithModelsCount', $tags);
		}

		return $tags;
	}
	/**
	 * Get tags array from comma separated tags string.
	 * @access private
	 * @param string|array $tags
	 * @return array
	 */
	protected function toTagsArray($tags) {
		if(!is_array($tags)){
			$tags = explode(',', trim(strip_tags($tags), ' ,'));
		}

		array_walk($tags, array($this, 'trim'));
		return $tags;
	}
	/**
	 * Used as a callback to trim tags.
	 * @access private
	 * @param string $item
	 * @param string $key
	 * @return string
	 */
	private function trim(&$item, $key) {
		$item = trim($item);
	}
	/**
	 * If we need to save tags.
	 * @access private
	 * @return boolean
	 */
	private function needToSave() {
		$diff = array_merge(
			array_diff($this->tags, $this->originalTags),
			array_diff($this->originalTags, $this->tags)
		);

		return !empty($diff);
	}
	/**
	 * Saves model tags on model save.
	 * @param CModelEvent $event
	 * @throw Exception
	 */
	public function afterSave($event) {
		if($this->needToSave()){

			$builder = $this->getConnection()->getCommandBuilder();

			if(!$this->createTagsAutomatically){
				// checking if all of the tags are existing ones
				foreach($this->tags as $tag){

					$findCriteria = new CDbCriteria(array(
						'select' => "t.".$this->tagTablePk,
						'condition' => "t.{$this->tagTableName} = :tag ",
						'params' => array(':tag' => $tag),
					));
					if($this->getScopeCriteria()){
						$findCriteria->mergeWith($this->getScopeCriteria());
					}
					$tagId = $builder->createFindCommand(
						$this->tagTable,
						$findCriteria
					)->queryScalar();

					if(!$tagId){
						throw new Exception("Tag \"$tag\" does not exist. Please add it before assigning or enable createTagsAutomatically.");
					}

				}
			}

			if(!$this->getOwner()->getIsNewRecord()){
				// delete all present tag bindings if record is existing one
				$this->deleteTags();
			}

			// add new tag bindings and tags if there are any
			if(!empty($this->tags)){
				foreach($this->tags as $tag){
					if(empty($tag)) return;

					// try to get existing tag
					$findCriteria = new CDbCriteria(array(
						'select' => "t.".$this->tagTablePk,
						'condition' => "t.{$this->tagTableName} = :tag ",
						'params' => array(':tag' => $tag),
					));
					if($this->getScopeCriteria()){
						$findCriteria->mergeWith($this->getScopeCriteria());
					}
					$tagId = $builder->createFindCommand(
						$this->tagTable,
						$findCriteria
					)->queryScalar();

					// if there is no existing tag, create one
					if(!$tagId){
						$this->createTag($tag);

						// reset all tags cache
						$this->resetAllTagsCache();
						$this->resetAllTagsWithModelsCountCache();

						$tagId = $this->getConnection()->getLastInsertID();
					}

					// bind tag to it's model
					$builder->createInsertCommand(
						$this->getTagBindingTableName(),
						array(
							$this->getModelTableFkName() => $this->getOwner()->primaryKey,
							$this->tagBindingTableTagId => $tagId
						)
					)->execute();
				}
				$this->updateCount(+1);
			}


			$this->cache->set($this->getCacheKey(), $this->tags);
		}

		parent::afterSave($event);
	}
	/**
	 * Reset cache used for {@link getAllTags()}.
	 * @return void
	 */
	public function resetAllTagsCache() {
		$this->cache->delete('Taggable'.$this->getOwner()->tableName().'All');
	}
	/**
	 * Reset cache used for {@link getAllTagsWithModelsCount()}.
	 * @return void
	 */
	public function resetAllTagsWithModelsCountCache() {
		$this->cache->delete('Taggable'.$this->getOwner()->tableName().'AllWithCount');
	}
	/**
	 * Deletes tag bindings on model delete.
	 * @param CModelEvent $event
	 * @return void
	 */
	public function afterDelete($event) {
		// delete all present tag bindings
		$this->deleteTags();

		$this->cache->delete($this->getCacheKey());
		$this->resetAllTagsWithModelsCountCache();

		parent::afterDelete($event);
	}
	/**
	 * Load tags into model.
	 * @params array|CDbCriteria $criteria, defaults to null.
	 * @access protected
	 * @return void
	 */
	protected function loadTags($criteria = null) {
		if($this->tags != null) return;
		if($this->getOwner()->getIsNewRecord()) return;

		if(!($tags = $this->cache->get($this->getCacheKey()))){

			$findCriteria = new CDbCriteria(array(
				'select' => "t.{$this->tagTableName} as `name`",
				'join' => "INNER JOIN {$this->getTagBindingTableName()} et ON t.{$this->tagTablePk} = et.{$this->tagBindingTableTagId} ",
				'condition' => "et.{$this->getModelTableFkName()} = :ownerid ",
				'params' => array(
					':ownerid' => $this->getOwner()->primaryKey,
				)
			));
			if($criteria){
				$findCriteria->mergeWith($criteria);
			}
			if($this->getScopeCriteria()){
				$findCriteria->mergeWith($this->getScopeCriteria());
			}

			$tags = $this->getConnection()->getCommandBuilder()->createFindCommand(
				$this->tagTable,
				$findCriteria
			)->queryColumn();
			$this->cache->set($this->getCacheKey(), $tags);
		}

		$this->originalTags = $this->tags = $tags;
	}
	/**
	 * Returns key for caching specific model tags.
	 * @return string
	 */
	private function getCacheKey() {
		return $this->getCacheKeyBase().$this->getOwner()->primaryKey;
	}
	/**
	 * Returns cache key base.
	 * @return string
	 */
	private function getCacheKeyBase() {
		return 'Taggable'.
			$this->getOwner()->tableName().
			$this->tagTable.
			$this->tagBindingTable.
			$this->tagTableName.
			$this->getModelTableFkName().
			$this->tagBindingTableTagId.
			json_encode($this->scope);
	}
	/**
	 * Get criteria to limit query by tags.
	 * @access private
	 * @param array $tags
	 * @return CDbCriteria
	 */
	protected function getFindByTagsCriteria($tags) {
		$criteria = new CDbCriteria();

		$pk = $this->getOwner()->tableSchema->primaryKey;

		if(!empty($tags)){
			$conn = $this->getConnection();
			$criteria->select = 't.*';
			for($i = 0, $count = count($tags); $i < $count; $i++){
				$tag = $conn->quoteValue($tags[$i]);
				$criteria->join .=
					"JOIN {$this->getTagBindingTableName()} bt$i ON t.{$pk} = bt$i.{$this->getModelTableFkName()}
					JOIN {$this->tagTable} tag$i ON tag$i.{$this->tagTablePk} = bt$i.{$this->tagBindingTableTagId} AND tag$i.`{$this->tagTableName}` = $tag";
			}
		}

		if($this->getScopeCriteria()){
			$criteria->mergeWith($this->getScopeCriteria());
		}

		return $criteria;
	}
	/**
	 * Get all possible tags for current model class.
	 * @param CDbCriteria $criteria
	 * @return array
	 */
	public function getAllTags($criteria = null) {
		if(!($tags = $this->cache->get('Taggable'.$this->getOwner()->tableName().'All'))){
			// getting associated tags
			$builder = $this->getOwner()->getCommandBuilder();
			$findCriteria = new CDbCriteria();
			$findCriteria->select = $this->tagTableName;
			if($criteria){
				$findCriteria->mergeWith($criteria);
			}
			if($this->getScopeCriteria()){
				$findCriteria->mergeWith($this->getScopeCriteria());
			}
			$tags = $builder->createFindCommand($this->tagTable, $findCriteria)->queryColumn();

			$this->cache->set('Taggable'.$this->getOwner()->tableName().'All', $tags);
		}

		return $tags;
	}
	/**
	 * Get all possible tags with models count for each for this model class.
	 * @param CDbCriteria $criteria
	 * @return array
	 */
	public function getAllTagsWithModelsCount($criteria = null) {
		if(!($tags = $this->cache->get('Taggable'.$this->getOwner()->tableName().'AllWithCount'))){
			// getting associated tags
			$builder = $this->getOwner()->getCommandBuilder();

			$tagsCriteria = new CDbCriteria();

			if($this->tagTableCount !== null){
				$tagsCriteria->select = sprintf(
					"t.%s as `name`, %s as `count`",
					$this->tagTableName,
					$this->tagTableCount
				);
			}
			else{
				$tagsCriteria->select = sprintf(
					"t.%s as `name`, count(*) as `count`",
					$this->tagTableName
				);
				$tagsCriteria->join = sprintf(
					"JOIN `%s` et ON t.{$this->tagTablePk} = et.%s",
					$this->getTagBindingTableName(),
					$this->tagBindingTableTagId
				);
				$tagsCriteria->group = 't.'.$this->tagTablePk;
			}

			if($criteria!==null)
				$tagsCriteria->mergeWith($criteria);

			if($this->getScopeCriteria())
				$tagsCriteria->mergeWith($this->getScopeCriteria());


			$tags = $builder->createFindCommand($this->tagTable, $tagsCriteria)->queryAll();

			$this->cache->set('Taggable'.$this->getOwner()->tableName().'AllWithCount', $tags);
		}

		return $tags;
	}
	/**
	 * Finds out if model has all tags specified.
	 * @param string|array $tags
	 * @return boolean
	 */
	public function hasTags($tags) {
		$this->loadTags();

		$tags = $this->toTagsArray($tags);
		foreach($tags as $tag){
			if(!in_array($tag, $this->tags)) return false;
		}
		return true;
	}
	/**
	 * Alias of {@link hasTags()}.
	 * @param string|array $tags
	 * @return boolean
	 */
	public function hasTag($tags) {
		return $this->hasTags($tags);
	}
	/**
	 * Limit current AR query to have all tags specified.
	 * @param string|array $tags
	 * @return CActiveRecord
	 */
	public function taggedWith($tags) {
		$tags = $this->toTagsArray($tags);

		if(!empty($tags)){
			$criteria = $this->getFindByTagsCriteria($tags);
			$this->getOwner()->getDbCriteria()->mergeWith($criteria);
		}

		return $this->getOwner();
	}
	/**
	 * Alias of {@link taggedWith()}.
	 * @param string|array $tags
	 * @return CActiveRecord
	 */
	public function withTags($tags) {
		return $this->taggedWith($tags);
	}
	/**
	 * Delete all present tag bindings.
	 * @return void
	 */
	protected function deleteTags() {
		$this->updateCount(-1);

		$conn = $this->getConnection();
		$conn->createCommand(
			sprintf(
				"DELETE
                 FROM `%s`
                 WHERE %s = %d",
				$this->getTagBindingTableName(),
				$this->getModelTableFkName(),
				$this->getOwner()->primaryKey
			)
		)->execute();
	}
	/**
	 * Creates a tag.
	 * Method is for future inheritance.
	 * @param string $tag tag name.
	 * @return void
	 */
	protected function createTag($tag) {

		$builder = $this->getConnection()->getCommandBuilder();

		$values = array(
			$this->tagTableName => $tag
		);
		if(is_array($this->insertValues)){
			$values = array_merge($this->insertValues, $values);
		}

		$builder->createInsertCommand($this->tagTable, $values)->execute();

	}
	/**
	 * Updates counter information in database.
	 * Used if {@link tagTableCount} is not null.
	 * @param int $count incremental ("1") or decremental ("-1") value.
	 * @return void
	 */
	protected function updateCount($count) {
		if($this->tagTableCount !== null){
			$conn = $this->getConnection();
			$conn->createCommand(
				sprintf(
					"UPDATE %s
					SET %s = %s + %s
					WHERE %s in (SELECT %s FROM %s WHERE %s = %d)",
					$this->tagTable,
					$this->tagTableCount,
					$this->tagTableCount,
					$count,
					$this->tagTablePk,
					$this->tagBindingTableTagId,
					$this->getTagBindingTableName(),
					$this->getModelTableFkName(),
					$this->getOwner()->primaryKey
				)
			)->execute();
		}
	}
}