Add "findBy" magic method to Zend_Db_Table objects

My_Db_Table.php

<?php

/**
 * My_Db_Table
 *
 * Adds "findBy" magic method to Zend_Db_Table objects
 *
 * @author Eric Clemmons
 **/

class My_Db_Table extends Zend_Db_Table
{
    
    /**
     * Inflector to transpose "ColumNames" into "column_names"
     *
     * @var Zend_Filter_Inflector
     **/
    protected $_inflector;
    
    /**
     * Last fetched rowset for future queries
     *
     * @var Zend_Db_Table_Rowset
     **/
    protected $_lastRowset;
    
    /**
     * Delimiters for "where" clauses.  Last piece of glue is the default ("and")
     *
     * @var Array
     **/
    protected $_glue = array('or', 'and');
    
    /**
     * Initializes the inflector & actual table name ("posts" -> "wp_posts")
     *
     * @return void
     **/
    public function __construct()
    {
        $this->_initInflector();
        
        $this->_name = WORDPRESS_TABLE_PREFIX . $this->_name;
        
        parent::__construct();
    }
    
    /**
     * Sets up CamelCaseToUnderscore+StringToLower inflector
     *
     * @return void
     **/
    public function _initInflector()
    {
        $this->_inflector = new Zend_Filter_Inflector(':name');
        $this->_inflector->setRules(array(
             ':name'  => array('Word_CamelCaseToUnderscore', 'StringToLower')
        ));
    }
    
    /**
     * Sets up {$model}->findByColumName functions with optional And/Or clauses
     *
     * e.g. findByPostId(1)
     *          Row where "post_id" is equal to "1".
     *
     *      findByTagAndCategory('css', 'html')
     *          Rows where both "tag" and "category" is "css" and "html", respectively.
     *
     *      findByTagOrCategory('css', 'html')
     *          Rows where "tag" is "css" or "category" is "html"
     *
     * @return Zend_Db_Table_Rowset
     */
    public function __call($method, $args)
    {
        if (is_callable($this, $method)) {
            return call_user_func(array($this, $method));
        }
        
        preg_match('/^findBy([\w]+)$/', $method, $matches);
        
        $columns = array();
        
        foreach ($this->_glue as $glue) {
            if (strpos($matches[1], ucfirst($glue)) !== false) {
                break;
            }
        }
        
        foreach (explode(ucfirst($glue), $matches[1]) as $index => $column) {
            $columnName = $this->_inflector->filter(array('name' => $column));
            $columns[$columnName] = $args[$index];
        }
        
        return $this->findBy($columns, $glue);
    }
    
    /**
     * Concatenates columns & defined values based on "glue" delimiter
     *
     * @return Zend_Db_Table_Rowset
     **/
    public function findBy($columns, $glue = 'and')
    {
        $select = $this->select();
        
        foreach($columns as $column => $criteria) {
            $where = ($glue === 'or')
                   ? "orWhere"
                   : "where";
            
            $select = $select->{$where}("$column = ?", $criteria);
        }
        
        $this->_lastRowset = $this->fetchAll($select);
        
        return $this->_lastRowset;
    }
}