<?php
/**
 * WBEvent_Handler_TableUpdate
 *
 *
 * $Id: TableUpdate.php 516 2009-04-17 16:15:25Z gerd $
 *
 * @author gERD Schaufelberger <gerd@php-tools.net>
 * @license PHP License
 * @package WB
 * @subpackage base
 */

WBClass::load('WBEvent_Handler');

/**
 * WBEvent_Handler_TableUpdate
 *
 * Update a column in table
 *
 * @version 0.1.0
 * @package Wombat
 * @subpackage base
 */
class WBEvent_Handler_TableLoad extends WBEvent_Handler
{    
    /**
     * handler config
     * 
     * - table name of table to update
     * - key primary key of row to update
     * - keyindex data index where to achieve the primary key from
     * - target name of event's data array to fill with table values
     * - prefix merge loaded data with event data using prefix
     * 
     * @var array
     */
    protected $config   =   array(
                                'table'         =>  '',
                                'key'           =>  '',
                                'keyindex'      =>  'id',
                                'target'        =>  '',
                                'prefix'        =>  ''
                                );
    
    
    /**
     * update column in table
     *
     * Update exactly one column in one table for one row using primary key 
     * Hence primary key is required, as well as column and table name.
     * 
     * @param WBEvent $e
     * @return bool true to continue, false to stop processing
     * @throws Exception in case of error
     */
    public function process(WBEvent $e)
    {
        if (empty($this->config['table'])) {
            WBClass::load('WBException_Config');
            throw new WBException_Config('Table must not be empty!', 1, __CLASS__);            
        }
        
        $key    =   $this->config['key'];
        if (empty($key) && !empty($this->config['keyindex'])) {
            $key    =   $e->get($this->config['keyindex']);
        }
        if (empty($key) || $key == '__new') {
            WBClass::load('WBException_Config');
            throw new WBException_Config('Key may not be empty or "__new"', 3, __CLASS__);
        }
                
        $table  =   WBClass::create('WBDatasource_Table');

        $data   =   $table->get($this->config['table'], $key);
        if (1 != count($data)) {
            return false;
        }
        $data   =   $data[0];

        // store in target
        if (!empty($this->config['target'])) {
            $e->set($this->config['target'], $data);
            return true;
        }

        // merge with event data
        foreach ($data as $k => $v) {
            if (!empty($this->config['prefix'])) {
                $k  =   $this->config['prefix'] . $k;
            }
            $e->set($k, $v);
        }
        return true;
    }    
}