Enhanced parsing the accept header.

framework/web/Request.php

@@ -885,9 +885,23 @@ class Request extends \yii\base\Request
 
 	/**
 	 * Returns the content types acceptable by the end user.
-	 * This is determined by the `Accept` HTTP header.
-	 * @return array the content types ordered by the preference level. The first element
-	 * represents the most preferred content type.
+	 * This is determined by the `Accept` HTTP header. For example,
+	 *
+	 * ```php
+	 * $_SERVER['HTTP_ACCEPT'] = 'text/plain; q=0.5, application/json; version=1.0, application/xml; version=2.0;';
+	 * $types = $request->getAcceptableContentTypes();
+	 * print_r($types);
+	 * // displays:
+	 * // [
+	 * //     'application/json' => ['q' => 1, 'version' => '1.0'],
+	 * //      'application/xml' => ['q' => 1, 'version' => '2.0'],
+	 * //           'text/plain' => ['q' => 0.5],
+	 * // ]
+	 * ```
+	 *
+	 * @return array the content types ordered by the quality score. Types with the highest scores
+	 * will be returned first. The array keys are the content types, while the array values
+	 * are the corresponding quality score and other parameters as given in the header.
 	 */
 	public function getAcceptableContentTypes()
 	{
@@ -902,8 +916,12 @@ class Request extends \yii\base\Request
 	}
 
 	/**
+	 * Sets the acceptable content types.
+	 * Please refer to [[getAcceptableContentTypes()]] on the format of the parameter.
 	 * @param array $value the content types that are acceptable by the end user. They should
 	 * be ordered by the preference level.
+	 * @see getAcceptableContentTypes()
+	 * @see parseAcceptHeader()
 	 */
 	public function setAcceptableContentTypes($value)
 	{
@@ -937,7 +955,7 @@ class Request extends \yii\base\Request
 	{
 		if ($this->_languages === null) {
 			if (isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
-				$this->_languages = $this->parseAcceptHeader($_SERVER['HTTP_ACCEPT_LANGUAGE']);
+				$this->_languages = array_keys($this->parseAcceptHeader($_SERVER['HTTP_ACCEPT_LANGUAGE']));
 			} else {
 				$this->_languages = [];
 			}
@@ -956,45 +974,86 @@ class Request extends \yii\base\Request
 
 	/**
 	 * Parses the given `Accept` (or `Accept-Language`) header.
-	 * This method will return the acceptable values ordered by their preference level.
+	 *
+	 * This method will return the acceptable values with their quality scores and the corresponding parameters
+	 * as specified in the given `Accept` header. The array keys of the return value are the acceptable values,
+	 * while the array values consisting of the corresponding quality scores and parameters. The acceptable
+	 * values with the highest quality scores will be returned first. For example,
+	 *
+	 * ```php
+	 * $header = 'text/plain; q=0.5, application/json; version=1.0, application/xml; version=2.0;';
+	 * $accepts = $request->parseAcceptHeader($header);
+	 * print_r($accepts);
+	 * // displays:
+	 * // [
+	 * //     'application/json' => ['q' => 1, 'version' => '1.0'],
+	 * //      'application/xml' => ['q' => 1, 'version' => '2.0'],
+	 * //           'text/plain' => ['q' => 0.5],
+	 * // ]
+	 * ```
+	 *
 	 * @param string $header the header to be parsed
-	 * @return array the accept values ordered by their preference level.
+	 * @return array the acceptable values ordered by their quality score. The values with the highest scores
+	 * will be returned first.
 	 */
-	protected function parseAcceptHeader($header)
+	public function parseAcceptHeader($header)
 	{
 		$accepts = [];
-		$n = preg_match_all('/\s*([\w\/\-\*]+)\s*(?:;\s*q\s*=\s*([\d\.]+))?[^,]*/', $header, $matches, PREG_SET_ORDER);
-		for ($i = 0; $i < $n; ++$i) {
-			if (!empty($matches[$i][1])) {
-				$accepts[] = [$matches[$i][1], isset($matches[$i][2]) ? (float)$matches[$i][2] : 1, $i];
+		foreach (explode(',', $header) as $i => $part) {
+			$params = preg_split('/\s*;\s*/', trim($part), -1, PREG_SPLIT_NO_EMPTY);
+			if (empty($params)) {
+				continue;
+			}
+			$values = [
+				'q' => [$i, array_shift($params), 1],
+			];
+			foreach ($params as $param) {
+				if (strpos($param, '=') !== false) {
+					list ($key, $value) = explode('=', $param, 2);
+					if ($key === 'q') {
+						$values['q'][2] = (double)$value;
+					} else {
+						$values[$key] = $value;
+					}
+				} else {
+					$values[] = $param;
+				}
 			}
+			$accepts[] = $values;
 		}
+
 		usort($accepts, function ($a, $b) {
-			if ($a[1] > $b[1]) {
+			$a = $a['q']; // index, name, q
+			$b = $b['q'];
+			if ($a[2] > $b[2]) {
 				return -1;
-			} elseif ($a[1] < $b[1]) {
+			} elseif ($a[2] < $b[2]) {
 				return 1;
-			} elseif ($a[0] === $b[0]) {
-				return $a[2] > $b[2] ? 1 : -1;
-			} elseif ($a[0] === '*/*') {
+			} elseif ($a[1] === $b[1]) {
+				return $a[0] > $b[0] ? 1 : -1;
+			} elseif ($a[1] === '*/*') {
 				return 1;
-			} elseif ($b[0] === '*/*') {
+			} elseif ($b[1] === '*/*') {
 				return -1;
 			} else {
-				$wa = $a[0][strlen($a[0]) - 1] === '*';
-				$wb = $b[0][strlen($b[0]) - 1] === '*';
+				$wa = $a[1][strlen($a[1]) - 1] === '*';
+				$wb = $b[1][strlen($b[1]) - 1] === '*';
 				if ($wa xor $wb) {
 					return $wa ? 1 : -1;
 				} else {
-					return $a[2] > $b[2] ? 1 : -1;
+					return $a[0] > $b[0] ? 1 : -1;
 				}
 			}
 		});
+
 		$result = [];
 		foreach ($accepts as $accept) {
-			$result[] = $accept[0];
+			$name = $accept['q'][1];
+			$accept['q'] = $accept['q'][2];
+			$result[$name] = $accept;
 		}
-		return array_unique($result);
+
+		return $result;
 	}
 
 	/**

tests/unit/framework/web/RequestTest.php

+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yiiunit\framework\web;
+
+use yii\web\Request;
+use yiiunit\TestCase;
+
+/**
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @since 2.0
+ */
+class RequestTest extends TestCase
+{
+	public function testParseAcceptHeader()
+	{
+		$request = new Request;
+
+		$this->assertEquals([], $request->parseAcceptHeader(' '));
+
+		$this->assertEquals([
+			'audio/basic' => ['q' => 1],
+			'audio/*' => ['q' => 0.2],
+		], $request->parseAcceptHeader('audio/*; q=0.2, audio/basic'));
+
+		$this->assertEquals([
+			'application/json' => ['q' => 1, 'version' => '1.0'],
+			'application/xml' => ['q' => 1, 'version' => '2.0', 'x'],
+			'text/x-c' => ['q' => 1],
+			'text/x-dvi' => ['q' => 0.8],
+			'text/plain' => ['q' => 0.5],
+		], $request->parseAcceptHeader('text/plain; q=0.5,
+			application/json; version=1.0,
+			application/xml; version=2.0; x,
+			text/x-dvi; q=0.8, text/x-c'));
+	}
+}