Merge "Title: Refactor JS/CSS page handling to be more sane"

[lhc/web/wiklou.git] / languages / LanguageCode.php

diff --git a/languages/LanguageCode.php b/languages/LanguageCode.php
index 3fa3dc1..f50c55f 100644 (file)
--- a/languages/LanguageCode.php
+++ b/languages/LanguageCode.php
@@ -80,4 +80,36 @@ class LanguageCode {
                }
                return $code;
        }
+
+       /**
+        * Get the normalised IETF language tag
+        * See unit test for examples.
+        * See mediawiki.language.bcp47 for the JavaScript implementation.
+        *
+        * @param string $code The language code.
+        * @return string The language code which complying with BCP 47 standards.
+        *
+        * @since 1.31
+        */
+       public static function bcp47( $code ) {
+               $codeSegment = explode( '-', $code );
+               $codeBCP = [];
+               foreach ( $codeSegment as $segNo => $seg ) {
+                       // when previous segment is x, it is a private segment and should be lc
+                       if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
+                               $codeBCP[$segNo] = strtolower( $seg );
+                       // ISO 3166 country code
+                       } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
+                               $codeBCP[$segNo] = strtoupper( $seg );
+                       // ISO 15924 script code
+                       } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
+                               $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
+                       // Use lowercase for other cases
+                       } else {
+                               $codeBCP[$segNo] = strtolower( $seg );
+                       }
+               }
+               $langCode = implode( '-', $codeBCP );
+               return $langCode;
+       }
 }