app/modules/Application/Localization/GettextAdapter.php
<?php

/*
  +------------------------------------------------------------------------+
  | Phalcon Framework                                                      |
  +------------------------------------------------------------------------+
  | Copyright (c) 2011-2012 Phalcon Team (http://www.phalconphp.com)       |
  +------------------------------------------------------------------------+
  | This source file is subject to the New BSD License that is bundled     |
  | with this package in the file docs/LICENSE.txt.                        |
  |                                                                        |
  | If you did not receive a copy of the license and are unable to         |
  | obtain it through the world-wide-web, please send an email             |
  | to license@phalconphp.com so we can send you a copy immediately.       |
  +------------------------------------------------------------------------+
  | Authors: Andres Gutierrez <andres@phalconphp.com>                      |
  |          Eduar Carvajal <eduar@phalconphp.com>                         |
  +------------------------------------------------------------------------+
 */

namespace Application\Localization;

use Phalcon\Translate\Adapter,
    Phalcon\Translate\AdapterInterface,
    Phalcon\Translate\Exception;

class GettextAdapter extends Adapter implements AdapterInterface
{

    /**
     * Phalcon\Translate\Adapter\Gettext constructor
     *
     * @param array $options
     */
    public function __construct($options)
    {

        if (!is_array($options)) {
            throw new Exception('Invalid options');
        }

        if (!isset($options['locale'])) {
            throw new Exception('Parameter "locale" is required');
        }

        if (!isset($options['lang'])) {
            throw new Exception('Parameter "lang" is required');
        }

        if (!isset($options['file'])) {
            throw new Exception('Parameter "file" is required');
        }

        if (!isset($options['directory'])) {
            throw new Exception('Parameter "directory" is required');
        }

        putenv("LC_ALL=" . $options['locale']);
        putenv("LC_LANG=" . $options['lang']);
        setlocale(LC_ALL, $options['locale']);
        bindtextdomain($options['file'], $options['directory']);
        textdomain($options['file']);

        bind_textdomain_codeset($options['file'], 'UTF-8');

    }

    /**
     * Returns the translation related to the given key
     *
     * @param	string $index
     * @param	array $placeholders
     * @return	string
     */
    public function query($index, $placeholders = null)
    {
        if ($placeholders == null) {
            return gettext($index);
        }

        $translation = gettext($index);

        if (is_array($placeholders)) {
            foreach ($placeholders as $key => $value) {
                $translation = str_replace('%' . $key . '%', $value, $translation);
            }
        }

        return $translation;

    }

    /**
     * Check whether is defined a translation key in gettext
     *
     * @param 	string $index
     * @return	bool
     */
    public function exists($index)
    {
        return gettext($index) !== '';

    }

}