Improve documentation of the PageContentLanguage hook

Clarify that the type of second parameter that is being passed
to the hooks can be anything because one hook can change it and
then it is passed to another hook without the hook caller having
possibility to check or modify the value.

Clarify that hooks should only return Language objects.

Rename $wgLang to $userLang in the hook parameter documentation to
avoid false posivite matches for the global.

Fix some typos, use Title::inNamespace and add a test assertion.

Also, the $content parameter is unused by all implementations of
this method, and on quick look never passed by any caller. I kept
it for now, however.

Bug: T214358
Change-Id: Iae49d2998c2b762565d232c0337d84d43a4a900c

diff --git a/docs/hooks.txt b/docs/hooks.txt
index 8b5e4d7..645c0cd 100644 (file)
--- a/docs/hooks.txt
+++ b/docs/hooks.txt
@@ -2441,10 +2441,12 @@ $flags: Flags passed to WikiPage::doEditContent()
 $revision: New Revision of the article
 
 'PageContentLanguage': Allows changing the language in which the content of a
-page is written. Defaults to the wiki content language ($wgContLang).
+page is written. Defaults to the wiki content language.
 $title: Title object
-&$pageLang: the page content language (either an object or a language code)
-$wgLang: the user language
+&$pageLang: the page content language. Input can be anything (under control of
+  hook subscribers), but hooks should return Language objects. Language code
+  strings are deprecated.
+$userLang: the user language (Language or StubUserLang object)
 
 'PageContentSave': Before an article is saved.
 $wikiPage: the WikiPage (object) being saved

diff --git a/includes/content/ContentHandler.php b/includes/content/ContentHandler.php
index 49e3132..decbb0c 100644 (file)
--- a/includes/content/ContentHandler.php
+++ b/includes/content/ContentHandler.php
@@ -667,7 +667,7 @@ abstract class ContentHandler {
         * This default implementation just returns the content language (except for pages
         * in the MediaWiki namespace)
         *
-        * Note that the pages language is not cacheable, since it may in some
+        * Note that the page's language is not cacheable, since it may in some
         * cases depend on user settings.
         *
         * Also note that the page language may or may not depend on the actual content of the page,
@@ -684,7 +684,7 @@ abstract class ContentHandler {
                global $wgLang;
                $pageLang = MediaWikiServices::getInstance()->getContentLanguage();
 
-               if ( $title->getNamespace() == NS_MEDIAWIKI ) {
+               if ( $title->inNamespace( NS_MEDIAWIKI ) ) {
                        // Parse mediawiki messages with correct target language
                        list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $title->getText() );
                        $pageLang = Language::factory( $lang );

diff --git a/tests/phpunit/includes/content/ContentHandlerTest.php b/tests/phpunit/includes/content/ContentHandlerTest.php
index a8ea3f0..f42f8b4 100644 (file)
--- a/tests/phpunit/includes/content/ContentHandlerTest.php
+++ b/tests/phpunit/includes/content/ContentHandlerTest.php
@@ -158,6 +158,7 @@ class ContentHandlerTest extends MediaWikiTestCase {
                $handler = ContentHandler::getForTitle( $title );
                $lang = $handler->getPageLanguage( $title );
 
+               $this->assertInstanceOf( Language::class, $lang );
                $this->assertEquals( $expected->getCode(), $lang->getCode() );
        }