<?php
/**
 * WBEvent_Handler_TableUpdate
 *
 *
 * $Id$
 *
 * @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 0.2.0
 * @package Wombat
 * @subpackage base
 */
class WBEvent_Handler_TableUpdate extends WBEvent_Handler
{    
    /**
     * handler config
     * 
     * - table name of table to update
     * - column name of column to update
     * - value new value
     * - valueindex data index where to load the value from
     * - key primary key of row to update
     * - keyindex data index where to achieve the primary key from
     * 
     * @var array
     */
    protected $config   =   array(
                                'table'         =>  '',
                                'column'        =>  '',
                                'value'         =>  '',
                                'valueindex'    =>  '',
                                'key'           =>  '',
                                'keyindex'      =>  '',
                                'dbconfig'      =>  ''
                                );
    
    
    /**
     * 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__);            
        }
        if (empty($this->config['column'])) {
            WBClass::load('WBException_Config');
            throw new WBException_Config('Column must not be empty!', 2, __CLASS__);            
        }
        if (empty($this->config['dbconfig'])) {
            $params['dbconfig'] =   'config';
        }

        $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__);
        }
                
        $value  =   $this->config['value'];
        if (empty($value) && !empty($this->config['valueindex'])) {
            $value  =   $e->get($this->config['valueindex']);
        }
        
        $params =   array(
                    'dbconfig'  =>  $this->config['dbconfig']
                );
        /** @var $table WBDatasource_Table */
        $table  =   WBClass::create('WBDatasource_Table', $params);
        

        WBClass::load('WBString');
        $value  =   WBString::populate($value, $e->get());
        // update
        $save   =   array(
                        $this->config['column'] => $value
                    );

        $table->save($this->config['table'], $key, $save);
        return true;
    }    
}