Yii DynamicRelationBehavior

DynamicRelationBehavior.php

class DynamicRelationBehavior extends CActiveRecordBehavior
{
    /**
     * @var string name of the relation which will be added to the owner dynamically
     */
    public $relationName = 'posts';
 
    public function afterFind($event)
    {
        $this->addRelation();
    }
 
    public function afterConstruct($event)
    {
        $this->addRelation();
    }
 
    protected function addRelation()
    {
        // quit if relation is already attached
        if ($this->owner->getMetaData()->hasRelation($this->relationName)) return;
 
        $this->owner->getMetaData()->addRelation($this->relationName, array(
            CActiveRecord::HAS_MANY,
            'Post',
            'author_id',
        ));
    }
}