MediaWiki 1.30.2

[autoinstallsdev/mediawiki.git] / includes / libs / http / HttpAcceptParser.php

diff --git a/includes/libs/http/HttpAcceptParser.php b/includes/libs/http/HttpAcceptParser.php
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+<?php
+
+/**
+ * Utility for parsing a HTTP Accept header value into a weight map. May also be used with
+ * other, similar headers like Accept-Language, Accept-Encoding, etc.
+ *
+ * @license GPL-2.0+
+ * @author Daniel Kinzler
+ */
+
+namespace Wikimedia\Http;
+
+class HttpAcceptParser {
+
+       /**
+        * Parses an HTTP header into a weight map, that is an associative array
+        * mapping values to their respective weights. Any header name preceding
+        * weight spec is ignored for convenience.
+        *
+        * This implementation is partially based on the code at
+        * http://www.thefutureoftheweb.com/blog/use-accept-language-header
+        *
+        * Note that type parameters and accept extension like the "level" parameter
+        * are not supported, weights are derived from "q" values only.
+        *
+        * @todo: If additional type parameters are present, ignore them cleanly.
+        *        At present, they often confuse the result.
+        *
+        * See HTTP/1.1 section 14 for details.
+        *
+        * @param string $rawHeader
+        *
+        * @return array
+        */
+       public function parseWeights( $rawHeader ) {
+               //FIXME: The code below was copied and adapted from WebRequest::getAcceptLang.
+               //       Move this utility class into core for reuse!
+
+               // first, strip header name
+               $rawHeader = preg_replace( '/^[-\w]+:\s*/', '', $rawHeader );
+
+               // Return values in lower case
+               $rawHeader = strtolower( $rawHeader );
+
+               // Break up string into pieces (values and q factors)
+               $value_parse = null;
+               preg_match_all( '@([a-z\d*]+([-+/.][a-z\d*]+)*)\s*(;\s*q\s*=\s*(1(\.0{0,3})?|0(\.\d{0,3})?)?)?@',
+                       $rawHeader, $value_parse );
+
+               if ( !count( $value_parse[1] ) ) {
+                       return [];
+               }
+
+               $values = $value_parse[1];
+               $qvalues = $value_parse[4];
+               $indices = range( 0, count( $value_parse[1] ) - 1 );
+
+               // Set default q factor to 1
+               foreach ( $indices as $index ) {
+                       if ( $qvalues[$index] === '' ) {
+                               $qvalues[$index] = 1;
+                       } elseif ( $qvalues[$index] == 0 ) {
+                               unset( $values[$index], $qvalues[$index], $indices[$index] );
+                       } else {
+                               $qvalues[$index] = (float)$qvalues[$index];
+                       }
+               }
+
+               // Sort list. First by $qvalues, then by order. Reorder $values the same way
+               array_multisort( $qvalues, SORT_DESC, SORT_NUMERIC, $indices, $values );
+
+               // Create a list like "en" => 0.8
+               $weights = array_combine( $values, $qvalues );
+
+               return $weights;
+       }
+
+}