AdjacencyListBehavior.php

<?php
/**
 * AdjacencyListBehavior
 *
 * @author Alexander Kochetov <creocoder@gmail.com>
 * @link https://github.com/yiiext/adjacency-list-behavior
 * @author Jon Langevin <intel352@gmail.com>
 * @link https://github.com/intel352/adjacency-list-behavior
 */

/**
 * Provides adjacency list functionality for a model.
 *
 * @version 0.30
 * @package yiiext.behaviors.model.trees.al
 */
class AdjacencyListBehavior extends CActiveRecordBehavior
{
	const PARENT='parent';
	const CHILDREN='children';
    const BOTH='both';
    
	public $hasLevel=false;
	public $hasWeight=false;
	public $parentAttribute='parent_id';
	public $levelAttribute='level';
	public $weightAttribute='weight';
	private $_ignoreEvent=false;
	private $_deleted=false;
	private $_id;

	/**
	 * Named scope. Gets ancestors for node.
	 * @param int depth
	 * @return CActiveRecord the owner
	 */
	public function ancestors($depth=null)
    {
        return $this->genealogy(self::PARENT, $depth);
    }

	/**
	 * Named scope. Gets descendants for node.
	 * @param int depth
	 * @return CActiveRecord the owner
	 */
	public function descendants($depth=null)
    {
        return $this->genealogy(self::CHILDREN, $depth);
    }
    
	/**
	 * Named scope. Gets genealogy (family tree) for node.
	 * @param int depth
	 * @return CActiveRecord the owner
	 */
	public function genealogy($type=self::BOTH, $depth=null)
	{
		/**
         * @todo check hasLevel if $depth===null
         */
        
        if($type==self::BOTH)
            $type=array(self::PARENT,self::CHILDREN);
        else
            $type=array($type);

		$owner=$this->getOwner();
		$db=$owner->getDbConnection();
		$criteria=$owner->getDbCriteria();
		$alias=$owner->getTableAlias(true);

        foreach($type AS $t)
		{
            if($owner->primaryKey==null) {
                $depth=1;
            }else{
                switch($t) {
                    case self::PARENT:
                        if($owner->{$this->parentAttribute}==null)
                            continue;
                        $criteria->addColumnCondition(array($alias.'.'.$db->quoteColumnName($this->owner->getTableSchema()->getTable()->primaryKey)=>$owner->{$this->parentAttribute}));
                        break;
                    case self::CHILDREN:
                        $criteria->addColumnCondition(array($alias.'.'.$db->quoteColumnName($this->parentAttribute)=>$owner->primaryKey));
                        break;
                }
            }

            if($depth>0)
                $with=array($t);
            if($depth>1)
			{
    			for($i=1;$i<$depth-1;$i++)
                {
                    $with=array(
                        $t=>array(
                            'with'=>$with,
                            'alias'=>$t.$i,
                        ),
                    );
                }
			}
            if(!empty($with))
                $criteria->mergeWith(array('with'=>$with));
		}

		return $owner;
	}

	/**
	 * Named scope. Gets children for node (direct descendants only).
	 * @return CActiveRecord the owner
	 */
	public function withChildren()
	{
		return $this->descendants(1);
	}
    
    public function roots()
    {
		$owner=$this->getOwner();
		$db=$owner->getDbConnection();
		$criteria=$owner->getDbCriteria();
		$alias=$owner->getTableAlias(true);
        
        $criteria->addColumnCondition(array($alias.'.'.$db->quoteColumnName($this->parentAttribute)=>null));
        return $owner;
    }

	/**
	 * Gets root node.
     * @todo Is the original intention here to get the root of the current tree? If so, this logic fails
     * @todo Using level, build query condition instead of looping records
	 * @return CActiveRecord the record found. Null if no record is found
	 */
	public function getRoot()
	{
		$owner=$this->getOwner();
		#$db=$owner->getDbConnection();
		#$owner->getDbCriteria()->addColumnCondition(array($owner->getTableAlias(true).'.'.$db->quoteColumnName($this->parentAttribute)=>null));
        
        if(!$this->getParent())
            return $owner;
        else
            return $this->getParent()->getRoot();
	}

	/**
	 * Gets record of node parent.
	 * @return CActiveRecord the record found. Null if no record is found
	 */
	public function getParent()
	{
        /**
         * Return the record using already defined relationship, fall back to Yii AR handling
         */
        return $this->getOwner()->{self::PARENT};
	}

	/**
	 * Gets record of node children.
	 * @return CActiveRecord the records found. Null if no record is found
	 */
	public function getChildren()
	{
        /**
         * Return the record using already defined relationship, fall back to Yii AR handling
         */
        return $this->getOwner()->{self::CHILDREN};
	}

	/**
	 * Gets record of previous sibling.
	 * @return CActiveRecord the record found. Null if no record is found
	 */
	public function getPrevSibling()
	{
		//only if level future is on
	}

	/**
	 * Gets record of next sibling.
	 * @return CActiveRecord the record found. Null if no record is found
	 */
	public function getNextSibling()
	{
		//only if level future is on
	}

	/**
	 * Update node if it's not new.
	 * @return boolean whether the saving succeeds
	 */
	public function save($runValidation=true,$attributes=null)
	{
		$owner=$this->getOwner();

		if($runValidation && !$owner->validate($attributes))
			return false;

		if($owner->getIsNewRecord())
            throw new CDbException(Yii::t('yiiext','Placeholder error'));

		$this->_ignoreEvent=true;
		$result=$owner->update($attributes);
		$this->_ignoreEvent=false;

		return $result;
	}

	public function saveNode($runValidation=true,$attributes=null)
	{
		return $this->save($runValidation,$attributes);
	}

	/**
	 * Deletes node and it's descendants.
	 * @return boolean whether the deletion is successful
	 */
	public function delete()
	{
		// cascad ?
	}

	public function deleteNode()
	{
		return $this->delete();
	}

	/**
	 * Appends node to target as last child.
	 * @return boolean whether the appending succeeds
	 */
	public function appendTo($target,$runValidation=true,$attributes=null)
	{
	}

	/**
	 * Appends target to node as last child.
	 * @return boolean whether the appending succeeds
	 */
	public function append($target,$runValidation=true,$attributes=null)
	{
		return $target->appendTo($this->getOwner(),$runValidation,$attributes);
	}

	/**
	 * Move node as last child of target.
	 * @return boolean whether the moving succeeds
	 */
	public function moveAsLast($target)
	{
		// check hasWeight
	}

	/**
	 * Determines if node is descendant of subject node.
	 * @return boolean
	 */
	public function isDescendantOf($subj)
	{
	}

	/**
	 * Determines if node is leaf.
	 * @return boolean
	 */
	public function isLeaf()
	{
	}

	public function getIsDeletedRecord()
	{
		return $this->_deleted;
	}

	public function setIsDeletedRecord($value)
	{
		$this->_deleted=$value;
	}
    
    public function attach($owner) {
        parent::attach($owner);
        
        $owner=$this->getOwner();
        /**
         * Adding relation types
         */
        $owner->getMetaData()->addRelation(self::PARENT,array(CActiveRecord::HAS_ONE,get_class($owner),$this->parentAttribute));
        $owner->getMetaData()->addRelation(self::CHILDREN,array(CActiveRecord::HAS_MANY,get_class($owner),$this->parentAttribute));
    }

	public function beforeSave($event)
	{
		if($this->_ignoreEvent)
			return true;
		else
			throw new CDbException(Yii::t('yiiext','You should not use CActiveRecord::save() method when AjacencyListBehavior attached.'));
	}

	public function beforeDelete($event)
	{
		if($this->_ignoreEvent)
			return true;
		else
			throw new CDbException(Yii::t('yiiext','You should not use CActiveRecord::delete() method when AjacencyListBehavior attached.'));
	}

	private function correctCachedOnDelete()
	{
	}

	private function correctCachedOnAddNode()
	{
	}
}