Initial Gettext support.

12 years ago · 124b153350
9 changed files with 728 additions and 0 deletions
--- a/tests/unit/data/i18n/test.mo
+++ b/tests/unit/data/i18n/test.mo
--- a/tests/unit/data/i18n/test.po
+++ b/tests/unit/data/i18n/test.po
@ -0,0 +1,64 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: \n"
+"POT-Creation-Date: \n"
+"PO-Revision-Date: \n"
+"Last-Translator: resurtm <resurtm@gmail.com>\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 1.5.5\n"
+
+msgctxt "context1"
+msgid ""
+"Aliquam tempus elit vel purus molestie placerat. In sollicitudin tincidunt\n"
+"aliquet. Integer tincidunt gravida tempor. In convallis blandit dui vel "
+"malesuada.\n"
+"Nunc vel sapien nunc, a pretium nulla."
+msgstr ""
+"Олицетворение однократно. Представленный лексико-семантический анализ "
+"является\n"
+"психолингвистическим в своей основе, но механизм сочленений полидисперсен. "
+"Впечатление\n"
+"однократно. Различное расположение выбирает сюжетный механизм сочленений."
+
+msgctxt "context1"
+msgid "String number two."
+msgstr "Строка номер два."
+
+msgctxt "context2"
+msgid ""
+"The other\n"
+"\n"
+"context.\n"
+msgstr ""
+"Другой\n"
+"\n"
+"контекст.\n"
+
+msgctxt "context1"
+msgid ""
+"Missing\n"
+"\r\t\"translation."
+msgstr ""
+
+msgctxt "context1"
+msgid ""
+"Nunc vel sapien nunc, a pretium nulla.\n"
+"Pellentesque habitant morbi tristique senectus et netus et malesuada fames "
+"ac turpis egestas."
+msgstr "Короткий перевод."
+
+msgid "contextless"
+msgstr ""
+
+msgctxt "context2"
+msgid ""
+"test1\\ntest2\n"
+"\\\n"
+"test3"
+msgstr ""
+"тест1\\nтест2\n"
+"\\\n"
+"тест3"
--- a/tests/unit/framework/i18n/GettextMessageSourceTest.php
+++ b/tests/unit/framework/i18n/GettextMessageSourceTest.php
@ -0,0 +1,14 @@
+<?php
+
+namespace yiiunit\framework\i18n;
+
+use yii\i18n\GettextMessageSource;
+use yiiunit\TestCase;
+
+class GettextMessageSourceTest extends TestCase
+{
+	public function testLoadMessages()
+	{
+		$this->markTestSkipped();
+	}
+}
--- a/tests/unit/framework/i18n/GettextMoFileTest.php
+++ b/tests/unit/framework/i18n/GettextMoFileTest.php
@ -0,0 +1,95 @@
+<?php
+
+namespace yiiunit\framework\i18n;
+
+use yii\i18n\GettextMoFile;
+use yiiunit\TestCase;
+
+class GettextMoFileTest extends TestCase
+{
+	public function testLoad()
+	{
+		$moFile = new GettextMoFile();
+		$moFilePath = __DIR__ . '/../../data/i18n/test.mo';
+		$context1 = $moFile->load($moFilePath, 'context1');
+		$context2 = $moFile->load($moFilePath, 'context2');
+
+		// item count
+		$this->assertCount(3, $context1);
+		$this->assertCount(2, $context2);
+
+		// original messages
+		$this->assertArrayNotHasKey("Missing\n\r\t\"translation.", $context1);
+		$this->assertArrayHasKey("Aliquam tempus elit vel purus molestie placerat. In sollicitudin tincidunt\naliquet. Integer tincidunt gravida tempor. In convallis blandit dui vel malesuada.\nNunc vel sapien nunc, a pretium nulla.", $context1);
+		$this->assertArrayHasKey("String number two.", $context1);
+		$this->assertArrayHasKey("Nunc vel sapien nunc, a pretium nulla.\nPellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas.", $context1);
+
+		$this->assertArrayHasKey("The other\n\ncontext.\n", $context2);
+		$this->assertArrayHasKey("test1\\ntest2\n\\\ntest3", $context2);
+
+		// translated messages
+		$this->assertFalse(in_array("", $context1));
+		$this->assertTrue(in_array("Олицетворение однократно. Представленный лексико-семантический анализ является\nпсихолингвистическим в своей основе, но механизм сочленений полидисперсен. Впечатление\nоднократно. Различное расположение выбирает сюжетный механизм сочленений.", $context1));
+		$this->assertTrue(in_array('Строка номер два.', $context1));
+		$this->assertTrue(in_array('Короткий перевод.', $context1));
+
+		$this->assertTrue(in_array("Другой\n\nконтекст.\n", $context2));
+		$this->assertTrue(in_array("тест1\\nтест2\n\\\nтест3", $context2));
+	}
+
+	public function testSave()
+	{
+		// initial data
+		$s = chr(4);
+		$messages = array(
+			'Hello!' => 'Привет!',
+			"context1{$s}Hello?" => 'Привет?',
+			'Hello!?' => '',
+			"context1{$s}Hello!?!" => '',
+			"context2{$s}\"Quotes\"" => '"Кавычки"',
+			"context2{$s}\nNew lines\n" => "\nПереносы строк\n",
+			"context2{$s}\tTabs\t" => "\tТабы\t",
+			"context2{$s}\rCarriage returns\r" => "\rВозвраты кареток\r",
+		);
+
+		// create temporary directory and dump messages
+		$poFileDirectory = __DIR__ . '/../../runtime/i18n';
+		if (!is_dir($poFileDirectory)) {
+			mkdir($poFileDirectory);
+		}
+		if (is_file($poFileDirectory . '/test.mo')) {
+			unlink($poFileDirectory . '/test.mo');
+		}
+
+		$moFile = new GettextMoFile();
+		$moFile->save($poFileDirectory . '/test.mo', $messages);
+
+		// load messages
+		$context1 = $moFile->load($poFileDirectory . '/test.mo', 'context1');
+		$context2 = $moFile->load($poFileDirectory . '/test.mo', 'context2');
+
+		// context1
+		$this->assertCount(2, $context1);
+
+		$this->assertArrayHasKey('Hello?', $context1);
+		$this->assertTrue(in_array('Привет?', $context1));
+
+		$this->assertArrayHasKey('Hello!?!', $context1);
+		$this->assertTrue(in_array('', $context1));
+
+		// context2
+		$this->assertCount(4, $context2);
+
+		$this->assertArrayHasKey("\"Quotes\"", $context2);
+		$this->assertTrue(in_array('"Кавычки"', $context2));
+
+		$this->assertArrayHasKey("\nNew lines\n", $context2);
+		$this->assertTrue(in_array("\nПереносы строк\n", $context2));
+
+		$this->assertArrayHasKey("\tTabs\t", $context2);
+		$this->assertTrue(in_array("\tТабы\t", $context2));
+
+		$this->assertArrayHasKey("\rCarriage returns\r", $context2);
+		$this->assertTrue(in_array("\rВозвраты кареток\r", $context2));
+	}
+}
--- a/tests/unit/framework/i18n/GettextPoFileTest.php
+++ b/tests/unit/framework/i18n/GettextPoFileTest.php
@ -0,0 +1,95 @@
+<?php
+
+namespace yiiunit\framework\i18n;
+
+use yii\i18n\GettextPoFile;
+use yiiunit\TestCase;
+
+class GettextPoFileTest extends TestCase
+{
+	public function testLoad()
+	{
+		$poFile = new GettextPoFile();
+		$poFilePath = __DIR__ . '/../../data/i18n/test.po';
+		$context1 = $poFile->load($poFilePath, 'context1');
+		$context2 = $poFile->load($poFilePath, 'context2');
+
+		// item count
+		$this->assertCount(4, $context1);
+		$this->assertCount(2, $context2);
+
+		// original messages
+		$this->assertArrayHasKey("Missing\n\r\t\"translation.", $context1);
+		$this->assertArrayHasKey("Aliquam tempus elit vel purus molestie placerat. In sollicitudin tincidunt\naliquet. Integer tincidunt gravida tempor. In convallis blandit dui vel malesuada.\nNunc vel sapien nunc, a pretium nulla.", $context1);
+		$this->assertArrayHasKey("String number two.", $context1);
+		$this->assertArrayHasKey("Nunc vel sapien nunc, a pretium nulla.\nPellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas.", $context1);
+
+		$this->assertArrayHasKey("The other\n\ncontext.\n", $context2);
+		$this->assertArrayHasKey("test1\\\ntest2\n\\\\\ntest3", $context2);
+
+		// translated messages
+		$this->assertTrue(in_array("", $context1));
+		$this->assertTrue(in_array("Олицетворение однократно. Представленный лексико-семантический анализ является\nпсихолингвистическим в своей основе, но механизм сочленений полидисперсен. Впечатление\nоднократно. Различное расположение выбирает сюжетный механизм сочленений.", $context1));
+		$this->assertTrue(in_array('Строка номер два.', $context1));
+		$this->assertTrue(in_array('Короткий перевод.', $context1));
+
+		$this->assertTrue(in_array("Другой\n\nконтекст.\n", $context2));
+		$this->assertTrue(in_array("тест1\\\nтест2\n\\\\\nтест3", $context2));
+	}
+
+	public function testSave()
+	{
+		// initial data
+		$s = chr(4);
+		$messages = array(
+			'Hello!' => 'Привет!',
+			"context1{$s}Hello?" => 'Привет?',
+			'Hello!?' => '',
+			"context1{$s}Hello!?!" => '',
+			"context2{$s}\"Quotes\"" => '"Кавычки"',
+			"context2{$s}\nNew lines\n" => "\nПереносы строк\n",
+			"context2{$s}\tTabs\t" => "\tТабы\t",
+			"context2{$s}\rCarriage returns\r" => "\rВозвраты кареток\r",
+		);
+
+		// create temporary directory and dump messages
+		$poFileDirectory = __DIR__ . '/../../runtime/i18n';
+		if (!is_dir($poFileDirectory)) {
+			mkdir($poFileDirectory);
+		}
+		if (is_file($poFileDirectory . '/test.po')) {
+			unlink($poFileDirectory . '/test.po');
+		}
+
+		$poFile = new GettextPoFile();
+		$poFile->save($poFileDirectory . '/test.po', $messages);
+
+		// load messages
+		$context1 = $poFile->load($poFileDirectory . '/test.po', 'context1');
+		$context2 = $poFile->load($poFileDirectory . '/test.po', 'context2');
+
+		// context1
+		$this->assertCount(2, $context1);
+
+		$this->assertArrayHasKey('Hello?', $context1);
+		$this->assertTrue(in_array('Привет?', $context1));
+
+		$this->assertArrayHasKey('Hello!?!', $context1);
+		$this->assertTrue(in_array('', $context1));
+
+		// context2
+		$this->assertCount(4, $context2);
+
+		$this->assertArrayHasKey("\"Quotes\"", $context2);
+		$this->assertTrue(in_array('"Кавычки"', $context2));
+
+		$this->assertArrayHasKey("\nNew lines\n", $context2);
+		$this->assertTrue(in_array("\nПереносы строк\n", $context2));
+
+		$this->assertArrayHasKey("\tTabs\t", $context2);
+		$this->assertTrue(in_array("\tТабы\t", $context2));
+
+		$this->assertArrayHasKey("\rCarriage returns\r", $context2);
+		$this->assertTrue(in_array("\rВозвраты кареток\r", $context2));
+	}
+}
--- a/yii/i18n/GettextFile.php
+++ b/yii/i18n/GettextFile.php
@ -0,0 +1,37 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\i18n;
+
+use yii\base\Component;
+
+/**
+ * GettextFile is the base class for representing a Gettext message file.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @since 2.0
+ */
+abstract class GettextFile extends Component
+{
+	/**
+	 * Loads messages from a file.
+	 * @param string $filePath file path
+	 * @param string $context message context
+	 * @return array message translations. Array keys are source messages and array values are translated messages:
+	 * source message => translated message.
+	 */
+	abstract public function load($filePath, $context);
+
+	/**
+	 * Saves messages to a file.
+	 * @param string $filePath file path
+	 * @param array $messages message translations. Array keys are source messages and array values are
+	 * translated messages: source message => translated message. Note if the message has a context,
+	 * the message ID must be prefixed with the context with chr(4) as the separator.
+	 */
+	abstract public function save($filePath, $messages);
+}
--- a/yii/i18n/GettextMessageSource.php
+++ b/yii/i18n/GettextMessageSource.php
@ -0,0 +1,59 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\i18n;
+
+use Yii;
+
+class GettextMessageSource extends MessageSource
+{
+	const MO_FILE_EXT = '.mo';
+	const PO_FILE_EXT = '.po';
+
+	/**
+	 * @var string
+	 */
+	public $basePath = '@app/messages';
+	/**
+	 * @var string
+	 */
+	public $catalog = 'messages';
+	/**
+	 * @var boolean
+	 */
+	public $useMoFile = true;
+	/**
+	 * @var boolean
+	 */
+	public $useBigEndian = false;
+
+	protected function loadMessages($category, $language)
+	{
+		$messageFile = Yii::getAlias($this->basePath) . '/' . $language . '/' . $this->catalog;
+		if ($this->useMoFile) {
+			$messageFile .= static::MO_FILE_EXT;
+		} else {
+			$messageFile .= static::PO_FILE_EXT;
+		}
+
+		if (is_file($messageFile)) {
+			if ($this->useMoFile) {
+				$gettextFile = new GettextMoFile(array('useBigEndian' => $this->useBigEndian));
+			} else {
+				$gettextFile = new GettextPoFile();
+			}
+			$messages = $gettextFile->load($messageFile, $category);
+			if (!is_array($messages)) {
+				$messages = array();
+			}
+			return $messages;
+		} else {
+			Yii::error("The message file for category '$category' does not exist: $messageFile", __METHOD__);
+			return array();
+		}
+	}
+}
--- a/yii/i18n/GettextMoFile.php
+++ b/yii/i18n/GettextMoFile.php
@ -0,0 +1,267 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\i18n;
+
+use yii\base\Exception;
+
+/**
+ * GettextMoFile represents an MO Gettext message file.
+ *
+ * This class is written by adapting Michael's Gettext_MO class in PEAR.
+ * Please refer to the following license terms.
+ *
+ * Copyright (c) 2004-2005, Michael Wallner <mike@iworks.at>.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *     * Redistributions of source code must retain the above copyright notice,
+ *       this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @since 2.0
+ */
+class GettextMoFile extends GettextFile
+{
+	/**
+	 * @var boolean whether to use big-endian when reading and writing an integer.
+	 */
+	public $useBigEndian = false;
+
+	/**
+	 * Loads messages from an MO file.
+	 * @param string $filePath file path
+	 * @param string $context message context
+	 * @return array message translations. Array keys are source messages and array values are translated messages:
+	 * source message => translated message.
+	 */
+	public function load($filePath, $context)
+	{
+		if (false === ($fileHandle = @fopen($filePath, 'rb'))) {
+			throw new Exception('Unable to read file "' . $filePath . '".');
+		}
+		if (false === @flock($fileHandle, LOCK_SH)) {
+			throw new Exception('Unable to lock file "' . $filePath . '" for reading.');
+		}
+
+		// magic
+		$array = unpack('c', $this->readBytes($fileHandle, 4));
+		$magic = current($array);
+		if ($magic == -34) {
+			$this->useBigEndian = false;
+		} elseif ($magic == -107) {
+			$this->useBigEndian = true;
+		} else {
+			throw new Exception('Invalid MO file: ' . $filePath . ' (magic: ' . $magic . ').');
+		}
+
+		// revision
+		$revision = $this->readInteger($fileHandle);
+		if ($revision != 0) {
+			throw new Exception('Invalid MO file revision: ' . $revision . '.');
+		}
+
+		$count = $this->readInteger($fileHandle);
+		$sourceOffset = $this->readInteger($fileHandle);
+		$targetOffset = $this->readInteger($fileHandle);
+
+		$sourceLengths = array();
+		$sourceOffsets = array();
+		fseek($fileHandle, $sourceOffset);
+		for ($i = 0; $i < $count; ++$i) {
+			$sourceLengths[] = $this->readInteger($fileHandle);
+			$sourceOffsets[] = $this->readInteger($fileHandle);
+		}
+
+		$targetLengths = array();
+		$targetOffsets = array();
+		fseek($fileHandle, $targetOffset);
+		for ($i = 0; $i < $count; ++$i) {
+			$targetLengths[] = $this->readInteger($fileHandle);
+			$targetOffsets[] = $this->readInteger($fileHandle);
+		}
+
+		$messages = array();
+		for ($i = 0; $i < $count; ++$i) {
+			$id = $this->readString($fileHandle, $sourceLengths[$i], $sourceOffsets[$i]);
+			$separatorPosition = strpos($id, chr(4));
+
+			if (($context && $separatorPosition !== false && substr($id, 0, $separatorPosition) === $context) ||
+				(!$context && $separatorPosition === false)) {
+				if ($separatorPosition !== false) {
+					$id = substr($id,$separatorPosition+1);
+				}
+
+				$message = $this->readString($fileHandle, $targetLengths[$i], $targetOffsets[$i]);
+				$messages[$id] = $message;
+			}
+		}
+
+		@flock($fileHandle, LOCK_UN);
+		@fclose($fileHandle);
+		return $messages;
+	}
+
+	/**
+	 * Saves messages to an MO file.
+	 * @param string $filePath file path
+	 * @param array $messages message translations. Array keys are source messages and array values are
+	 * translated messages: source message => translated message. Note if the message has a context,
+	 * the message ID must be prefixed with the context with chr(4) as the separator.
+	 */
+	public function save($filePath, $messages)
+	{
+		if (false === ($fileHandle = @fopen($filePath, 'wb'))) {
+			throw new Exception('Unable to write file "' . $filePath . '".');
+		}
+		if (false === @flock($fileHandle, LOCK_EX)) {
+			throw new Exception('Unable to lock file "' . $filePath . '" for reading.');
+		}
+
+		// magic
+		if ($this->useBigEndian) {
+			$this->writeBytes($fileHandle, pack('c*', 0x95, 0x04, 0x12, 0xde)); // -107
+		} else {
+			$this->writeBytes($fileHandle, pack('c*', 0xde, 0x12, 0x04, 0x95)); // -34
+		}
+
+		// revision
+		$this->writeInteger($fileHandle, 0);
+
+		// message count
+		$messageCount = count($messages);
+		$this->writeInteger($fileHandle, $messageCount);
+
+		// offset of source message table
+		$offset = 28;
+		$this->writeInteger($fileHandle, $offset);
+		$offset += $messageCount * 8;
+		$this->writeInteger($fileHandle, $offset);
+
+		// hashtable size, omitted
+		$this->writeInteger($fileHandle, 0);
+		$offset += $messageCount * 8;
+		$this->writeInteger($fileHandle, $offset);
+
+		// length and offsets for source messages
+		foreach (array_keys($messages) as $id) {
+			$length = strlen($id);
+			$this->writeInteger($fileHandle, $length);
+			$this->writeInteger($fileHandle, $offset);
+			$offset += $length + 1;
+		}
+
+		// length and offsets for target messages
+		foreach ($messages as $message) {
+			$length = strlen($message);
+			$this->writeInteger($fileHandle, $length);
+			$this->writeInteger($fileHandle, $offset);
+			$offset += $length + 1;
+		}
+
+		// source messages
+		foreach (array_keys($messages) as $id) {
+			$this->writeString($fileHandle, $id);
+		}
+
+		// target messages
+		foreach ($messages as $message) {
+			$this->writeString($fileHandle, $message);
+		}
+
+		@flock($fileHandle, LOCK_UN);
+		@fclose($fileHandle);
+	}
+
+	/**
+	 * Reads one or several bytes.
+	 * @param resource $fileHandle to read from
+	 * @param integer $byteCount to be read
+	 * @return string bytes
+	 */
+	protected function readBytes($fileHandle, $byteCount = 1)
+	{
+		if ($byteCount > 0) {
+			return fread($fileHandle, $byteCount);
+		}
+	}
+
+	/**
+	 * Write bytes.
+	 * @param resource $fileHandle to write to
+	 * @param string $bytes to be written
+	 * @return integer how many bytes are written
+	 */
+	protected function writeBytes($fileHandle, $bytes)
+	{
+		return fwrite($fileHandle, $bytes);
+	}
+
+	/**
+	 * Reads a 4-byte integer.
+	 * @param resource $fileHandle to read from
+	 * @return integer the result
+	 */
+	protected function readInteger($fileHandle)
+	{
+		$array = unpack($this->useBigEndian ? 'N' : 'V', $this->readBytes($fileHandle, 4));
+		return current($array);
+	}
+
+	/**
+	 * Writes a 4-byte integer.
+	 * @param resource $fileHandle to write to
+	 * @param integer $integer to be written
+	 * @return integer how many bytes are written
+	 */
+	protected function writeInteger($fileHandle, $integer)
+	{
+		return $this->writeBytes($fileHandle, pack($this->useBigEndian ? 'N' : 'V', (int)$integer));
+	}
+
+	/**
+	 * Reads a string.
+	 * @param resource $fileHandle file handle
+	 * @param integer $length of the string
+	 * @param integer $offset of the string in the file. If null, it reads from the current position.
+	 * @return string the result
+	 */
+	protected function readString($fileHandle, $length, $offset = null)
+	{
+		if ($offset !== null) {
+			fseek($fileHandle, $offset);
+		}
+		return $this->readBytes($fileHandle, $length);
+	}
+
+	/**
+	 * Writes a string.
+	 * @param resource $fileHandle to write to
+	 * @param string $string to be written
+	 * @return integer how many bytes are written
+	 */
+	protected function writeString($fileHandle, $string)
+	{
+		return $this->writeBytes($fileHandle, $string. "\0");
+	}
+}
--- a/yii/i18n/GettextPoFile.php
+++ b/yii/i18n/GettextPoFile.php
@ -0,0 +1,97 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\i18n;
+
+use Yii;
+
+/**
+ * GettextPoFile represents a PO Gettext message file.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @since 2.0
+ */
+class GettextPoFile extends GettextFile
+{
+	/**
+	 * Loads messages from a PO file.
+	 * @param string $filePath file path
+	 * @param string $context message context
+	 * @return array message translations. Array keys are source messages and array values are translated messages:
+	 * source message => translated message.
+	 */
+	public function load($filePath, $context)
+	{
+		$pattern = '/(msgctxt\s+"(.*?(?<!\\\\))")?\s+' // context
+			. 'msgid\s+((?:".*(?<!\\\\)"\s*)+)\s+' // message ID, i.e. original string
+			. 'msgstr\s+((?:".*(?<!\\\\)"\s*)+)/'; // translated string
+		$content = file_get_contents($filePath);
+		$matches = array();
+		$matchCount = preg_match_all($pattern, $content, $matches);
+
+		$messages = array();
+		for ($i = 0; $i < $matchCount; ++$i) {
+			if ($matches[2][$i] == $context) {
+				$id = $this->decode($matches[3][$i]);
+				$message = $this->decode($matches[4][$i]);
+				$messages[$id] = $message;
+			}
+		}
+		return $messages;
+	}
+
+	/**
+	 * Saves messages to a PO file.
+	 * @param string $filePath file path
+	 * @param array $messages message translations. Array keys are source messages and array values are
+	 * translated messages: source message => translated message. Note if the message has a context,
+	 * the message ID must be prefixed with the context with chr(4) as the separator.
+	 */
+	public function save($filePath, $messages)
+	{
+		$content = '';
+		foreach ($messages as $id => $message) {
+			$separatorPosition = strpos($id, chr(4));
+			if ($separatorPosition !== false) {
+				$content .= 'msgctxt "' . substr($id, 0, $separatorPosition) . "\"\n";
+				$id = substr($id, $separatorPosition + 1);
+			}
+			$content .= 'msgid "' . $this->encode($id) . "\"\n";
+			$content .= 'msgstr "' . $this->encode($message) . "\"\n\n";
+		}
+		file_put_contents($filePath, $content);
+	}
+
+	/**
+	 * Encodes special characters in a message.
+	 * @param string $string message to be encoded
+	 * @return string the encoded message
+	 */
+	protected function encode($string)
+	{
+		return str_replace(
+			array('"', "\n", "\t", "\r"),
+			array('\\"', '\\n', '\\t', '\\r'),
+			$string
+		);
+	}
+
+	/**
+	 * Decodes special characters in a message.
+	 * @param string $string message to be decoded
+	 * @return string the decoded message
+	 */
+	protected function decode($string)
+	{
+		$string = preg_replace(
+			array('/"\s+"/', '/\\\\n/', '/\\\\r/', '/\\\\t/', '/\\\\"/'),
+			array('', "\n", "\r", "\t", '"'),
+			$string
+		);
+		return substr(rtrim($string), 1, -1);
+	}
+}