gistfile1.php

<?php
class AppModel extends Model {

	var $withFieldName = false;

	function beforeValidate(){
		foreach( $this->validate as $fieldname => $ruleSet ){
			foreach( $ruleSet as $rule => $rule_info ){

				if(!empty($this->validate[$fieldname][$rule]['rule'])) {
					$rule_option = $this->validate[$fieldname][$rule]['rule'];

				}

				if( $error_message = $this->_getErrorMessageI18n( $rule ) ) {
					$this->validate[$fieldname][$rule]['message'] = vsprintf($error_message, $rule_option);

				}elseif( !empty($this->validate[$fieldname][$rule]['message']) ){
					$this->validate[$fieldname][$rule]['message'] = __( $this->validate[$fieldname][$rule]['message'], true);
				}

				if( $this->withFieldName && !empty($this->validate[$fieldname][$rule]['message']) ){
					$this->validate[$fieldname][$rule]['message'] = __( $fieldname ,true) . ' : ' . $this->validate[$fieldname][$rule]['message'];
				}
			}
		}
		return true;
	}


	function _getErrorMessageI18n( $rule ){
		$error_messages = array(
			'require' 	=> 'Please be sure to input.',
			'email_invalid' => __('Invalid Email address.',true),
			'between' => __('Between %2$d and %3$d characters.',true),

		);

		if( array_key_exists($rule, $error_messages) ){
			return $error_messages[$rule];
		}else{
			return false;
		}
	}