Added an ICU string formatter that uses the MessageFormatter class

src/I18n/Formatter/IcuFormatter.php

@@ -0,0 +1,66 @@
+<?php
+/**
+ * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
+ * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
+ *
+ * Licensed under The MIT License
+ * For full copyright and license information, please see the LICENSE.txt
+ * Redistributions of files must retain the above copyright notice.
+ *
+ * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
+ * @link          http://cakephp.org CakePHP(tm) Project
+ * @since         3.0.0
+ * @license       http://www.opensource.org/licenses/mit-license.php MIT License
+ */
+namespace Cake\I18n\Formatter;
+
+use Aura\Intl\Exception;
+use Aura\Intl\FormatterInterface;
+use Cake\I18n\PluralRules;
+use MessageFormatter;
+
+/**
+ * A formatter that will interpolate variables using the MessageFormatter class
+ */
+class IcuFormatter implements FormatterInterface {
+
+/**
+ * Returns a string with all passed variables interpolated into the original
+ * message. Variables are interpolated using the MessageFormatter class.
+ *
+ * If an array is passed in `$message`, it will trigger the plural selection
+ * routine. Plural forms are selected depending on the locale and the `_count`
+ * key passed in `$vars`.
+ *
+ * @param string $locale The locale in which the message is presented.
+ * @param string|array $message The message to be translated
+ * @return string The formatted message
+ */
+	public function format($locale, $message, array $vars) {
+		if (!is_string($message)) {
+			$count = isset($vars['_count']) ? $vars['_count'] : 0;
+			$form = PluralRules::calculate($locale, $vars['_count']);
+			$message = $message[$form];
+		}
+
+		$formatter = new MessageFormatter($locale, $message);
+
+		if (!$formatter) {
+			throw new Exception\CannotInstantiateFormatter(
+				intl_get_error_message(),
+				intl_get_error_code()
+			);
+		}
+
+		$result = $formatter->format($vars);
+        if ($result === false) {
+            throw new Exception\CannotFormat(
+                $formatter->getErrorMessage(),
+                $formatter->getErrorCode()
+            );
+        }
+
+		return $result;
+	}
+
+}

tests/TestCase/I18n/Formatter/IcuFormatterTest.php

@@ -0,0 +1,102 @@
+<?php
+/**
+ * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
+ * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
+ *
+ * Licensed under The MIT License
+ * For full copyright and license information, please see the LICENSE.txt
+ * Redistributions of files must retain the above copyright notice.
+ *
+ * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
+ * @link          http://cakephp.org CakePHP(tm) Project
+ * @since         3.0.0
+ * @license       http://www.opensource.org/licenses/mit-license.php MIT License
+ */
+namespace Cake\Test\TestCase\I18n;
+
+use Cake\I18n\Formatter\IcuFormatter;
+use Cake\TestSuite\TestCase;
+
+/**
+ * IcuFormatter tests
+ *
+ */
+class IcuFormatterTest extends TestCase {
+
+/**
+ * Tests that variables are interpolated correctly
+ *
+ * @return void
+ */
+	public function testFormatSimple() {
+		$formatter = new IcuFormatter();
+		$this->assertEquals('Hello José', $formatter->format('en_US', 'Hello {0}', ['José']));
+		$result = $formatter->format(
+			'1 Orange',
+			'{count, number} {fruit}',
+			['count' => 1.0, 'fruit' => 'Orange']
+		);
+		$this->assertEquals('1 Orange', $result);
+	}
+
+/**
+ * Tests that plural forms can be selected using the PO file format plural forms
+ *
+ * @return void
+ */
+	public function testFormatPlural() {
+		$formatter = new IcuFormatter();
+		$messages = [
+			'{0} is 0',
+			'{0} is 1',
+			'{0} is 2',
+			'{0} is 3',
+			'{0} > 11'
+		];
+		$this->assertEquals('1 is 1', $formatter->format('ar', $messages, ['_count' => 1, 1]));
+		$this->assertEquals('2 is 2', $formatter->format('ar', $messages, ['_count' => 2, 2]));
+		$this->assertEquals('20 > 11', $formatter->format('ar', $messages, ['_count' => 20, 20]));
+	}
+
+/**
+ * Tests that plurals can instead be selected using ICU's native selector
+ *
+ * @return void
+ */
+	public function testNativePluralSelection() {
+		$formatter = new IcuFormatter();
+		$locale = 'en_US';
+		$string = '{fruits,plural,'
+			. '=0{No fruits.}'
+			. '=1{We have one fruit}'
+			. 'other{We have {count} fruits}'
+			. '}';
+
+		$params = ['fruits' => 0];
+		$expect = 'No fruits.';
+		$actual = $formatter->format($locale, $string, $params);
+		$this->assertSame($expect, $actual);
+
+		$params = ['fruits' => 1];
+		$expect = 'We have one fruit';
+		$actual = $formatter->format($locale, $string, $params);
+		$this->assertSame($expect, $actual);
+
+		$params = ['fruits' => 10, 'count' => 10];
+		$expect = 'We have 10 fruits';
+		$actual = $formatter->format($locale, $string, $params);
+		$this->assertSame($expect, $actual);
+	}
+
+/**
+ * Tests that passing a message in the wrong format will throw an exception
+ * 
+ * @expectedException Aura\Intl\Exception\CannotInstantiateFormatter
+ * @return void
+ */ 
+	public function testBadMessageFormat() {
+		$formatter = new IcuFormatter();
+		$formatter->format('en_US', '{crazy format', ['some', 'vars']);
+	}
+
+}