LanguageSelectorHooks.php

<?php

use MediaWiki\MediaWikiServices;

class LanguageSelectorHooks {
	public static function onRegistration() {
		global $wgLanguageSelectorDetectLanguage, $wgLanguageSelectorLocation, $wgParserOutputHooks;

		define( 'LANGUAGE_SELECTOR_USE_CONTENT_LANG', 0 ); # no detection
		define( 'LANGUAGE_SELECTOR_PREFER_CONTENT_LANG', 1 ); # use content language if accepted by the client
		define( 'LANGUAGE_SELECTOR_PREFER_CLIENT_LANG', 2 ); # use language most preferred by the client

		/**
		 * Language detection mode for anonymous visitors.
		 * Possible values:
		 * * LANGUAGE_SELECTOR_USE_CONTENT_LANG - use the $wgLanguageCode setting (default content language)
		 * * LANGUAGE_SELECTOR_PREFER_CONTENT_LANG - use the $wgLanguageCode setting, if accepted by the client
		 * * LANGUAGE_SELECTOR_PREFER_CLIENT_LANG - use the client's preferred language, if in $wgLanguageSelectorLanguages
		 */
		$wgLanguageSelectorDetectLanguage = LANGUAGE_SELECTOR_PREFER_CLIENT_LANG;

		define( 'LANGUAGE_SELECTOR_MANUAL', 0 ); # don't place anywhere
		define( 'LANGUAGE_SELECTOR_AT_TOP_OF_TEXT', 1 ); # put at the top of page content
		define( 'LANGUAGE_SELECTOR_IN_TOOLBOX', 2 ); # put into toolbox
		define( 'LANGUAGE_SELECTOR_AS_PORTLET', 3 ); # as portlet
		define( 'LANGUAGE_SELECTOR_INTO_SITENOTICE', 11 ); # put after sitenotice text
		define( 'LANGUAGE_SELECTOR_INTO_TITLE', 12 ); # put after title text
		define( 'LANGUAGE_SELECTOR_INTO_SUBTITLE', 13 ); # put after subtitle text
		define( 'LANGUAGE_SELECTOR_INTO_CATLINKS', 14 ); # put after catlinks text

		$wgLanguageSelectorLocation = LANGUAGE_SELECTOR_AT_TOP_OF_TEXT;

		$wgParserOutputHooks['languageselector'] = 'LanguageSelectorHooks::addJavascript';
	}

	public static function extension() {
		// We'll probably be beaten to this by the call in onUserGetLanguageObject(),
		// but just in case, call this to make sure the global is properly initialised
		self::getLanguageSelectorLanguages();
	}

	/**
	 * @param Parser $parser
	 */
	public static function onParserFirstCallInit( Parser $parser ) {
		$parser->setHook( 'languageselector', [ __CLASS__, 'languageSelectorTag' ] );
	}

	/**
	 * @return array
	 */
	public static function getLanguageSelectorLanguages() {
		global $wgLanguageSelectorLanguages, $wgLanguageSelectorShowAll;

		if ( $wgLanguageSelectorLanguages === null ) {
			$wgLanguageSelectorLanguages = array_keys( Language::fetchLanguageNames(
				null,
				$wgLanguageSelectorShowAll === true ? 'mw' : 'mwfile'
			) );
			sort( $wgLanguageSelectorLanguages );
		}

		return $wgLanguageSelectorLanguages;
	}

	/**
	 * @param User $user
	 * @param string &$code
	 */
	public static function onUserGetLanguageObject( $user, &$code ) {
		global $wgLanguageSelectorDetectLanguage,
			$wgCommandLineMode, $wgRequest;

		if ( $wgCommandLineMode ) {
			return;
		}

		$setlang = $wgRequest->getRawVal( 'setlang' );
		if ( $setlang && !in_array( $setlang, self::getLanguageSelectorLanguages() ) ) {
			$setlang = null; // ignore invalid
		}

		if ( $setlang ) {
			$wgRequest->response()->setcookie( 'LanguageSelectorLanguage', $setlang );
			$requestedLanguage = $setlang;
		} else {
			$requestedLanguage = $wgRequest->getCookie( 'LanguageSelectorLanguage' );
		}

		if ( $setlang && !$user->isAnon() ) {
			$userOptionsManager = MediaWikiServices::getInstance()->getUserOptionsManager();
			if ( $setlang != $userOptionsManager->getOption( $user, 'language' ) ) {
				$userOptionsManager->setOption( $user, 'language', $requestedLanguage );
				$userOptionsManager->saveOptions( $user );
				$code = $requestedLanguage;
			}
		}

		if ( !$wgRequest->getRawVal( 'uselang' ) && $user->isAnon() ) {
			if ( $wgLanguageSelectorDetectLanguage != LANGUAGE_SELECTOR_USE_CONTENT_LANG ) {
				if ( $requestedLanguage ) {
					$code = $requestedLanguage;
				} else {
					$languages = $wgRequest->getAcceptLang();

					// see if the content language is accepted by the client.
					if ( $wgLanguageSelectorDetectLanguage != LANGUAGE_SELECTOR_PREFER_CONTENT_LANG
						|| !array_key_exists( MediaWikiServices::getInstance()->getContentLanguage()->getCode(), $languages ) ) {

						$supported = self::getLanguageSelectorLanguages();
						// look for a language that is acceptable to the client
						// and known to the wiki.
						foreach ( $languages as $reqCode => $q ) {
							if ( in_array( $reqCode, $supported ) ) {
								$code = $reqCode;
								break;
							}
						}

						// Apparently Safari sends stupid things like "de-de" only.
						// Try again with stripped codes.
						foreach ( $languages as $reqCode => $q ) {
							$stupidPHP = explode( '-', $reqCode, 2 );
							$bareCode = array_shift( $stupidPHP );
							if ( in_array( $bareCode, $supported ) ) {
								$code = $bareCode;
								break;
							}
						}
					}
				}
			}
		}
	}

	/**
	 * @param OutputPage $out
	 * @param array &$cookies
	 */
	public static function onGetCacheVaryCookies( $out, &$cookies ) {
		global $wgCookiePrefix;

		$cookies[] = $wgCookiePrefix . 'LanguageSelectorLanguage';
	}

	/**
	 * @param string $input
	 * @param array $args
	 * @param Parser $parser
	 * @return string
	 */
	public static function languageSelectorTag( $input, $args, $parser ) {
		$style = $args['style'] ?? null;
		$class = $args['class'] ?? null;
		$selectorstyle = $args['selectorstyle'] ?? null;
		$buttonstyle = $args['buttonstyle'] ?? null;
		$showcode = $args['showcode'] ?? null;

		if ( $style ) {
			$style = htmlspecialchars( $style, ENT_QUOTES );
		}

		if ( $class ) {
			$class = htmlspecialchars( $class, ENT_QUOTES );
		}

		if ( $selectorstyle ) {
			$selectorstyle = htmlspecialchars( $selectorstyle, ENT_QUOTES );
		}

		if ( $buttonstyle ) {
			$buttonstyle = htmlspecialchars( $buttonstyle, ENT_QUOTES );
		}

		if ( $showcode ) {
			$showcode = strtolower( $showcode );

			if ( $showcode == 'true' || $showcode == 'yes' || $showcode == 'on' ) {
				$showcode = true;
			} elseif ( $showcode == 'false' || $showcode == 'no' || $showcode == 'off' ) {
				$showcode = false;
			} else {
				$showcode = null;
			}
		} else {
			$showcode = null;
		}

		# So that this also works with parser cache
		$parser->getOutput()->addOutputHook( 'languageselector' );

		return self::languageSelectorHTML( $parser->getTitle(), $style, $class, $selectorstyle, $buttonstyle, $showcode );
	}

	/**
	 * @param User $user
	 * @param bool $autocreated
	 */
	public static function onLocalUserCreated( $user, $autocreated ) {
		$context = RequestContext::getMain();

		// inherit language;
		// if the context user is the created user this means remembering what the user selected
		// otherwise, it would mean inheriting the language from the user creating the account.
		if ( $context->getUser() === $user ) {
			$userOptionsManager = MediaWikiServices::getInstance()->getUserOptionsManager();
			$userOptionsManager->setOption( $user, 'language', $context->getLanguage()->getCode() );
		}
	}

	/**
	 * @param OutputPage $outputPage
	 * @param ParserOutput $parserOutput
	 * @param mixed $data
	 */
	public static function addJavascript( $outputPage, $parserOutput, $data ) {
		$outputPage->addModules( 'ext.languageSelector' );
	}

	/**
	 * @param Title $title
	 * @param null|string $style
	 * @param null|string $class
	 * @param null|string $selectorstyle
	 * @param null|string $buttonstyle
	 * @param null|bool $showCode
	 * @return string
	 */
	public static function languageSelectorHTML( Title $title, $style = null, $class = null, $selectorstyle = null, $buttonstyle = null, $showCode = null ) {
		global $wgLang, $wgScript, $wgLanguageSelectorShowCode;

		if ( $showCode === null ) {
			$showCode = $wgLanguageSelectorShowCode;
		}

		static $id = 0;
		$id += 1;

		$code = $wgLang->getCode();

		$html = '';
		$html .= Xml::openElement( 'span', [
			'id' => 'languageselector-box-' . $id,
			'class' => 'languageselector ' . $class,
			'style' => $style
		] );

		$html .= Xml::openElement( 'form', [
			'name' => 'languageselector-form-' . $id,
			'id' => 'languageselector-form-' . $id,
			'method' => 'get',
			'action' => $wgScript,
			'style' => 'display:inline;'
		] );

		$html .= Html::hidden( 'title', $title->getPrefixedDBkey() );
		$html .= Xml::openElement( 'select', [
			'name' => 'setlang',
			'id' => 'languageselector-select-' . $id,
			'style' => $selectorstyle
		] );

		foreach ( self::getLanguageSelectorLanguages() as $ln ) {
			$name = Language::fetchLanguageName( $ln );
			if ( $showCode ) {
				$name = LanguageCode::bcp47( $ln ) . ' - ' . $name;
			}

			$html .= Xml::option( $name, $ln, $ln == $code );
		}

		$html .= Xml::closeElement( 'select' );
		$html .= Xml::submitButton( wfMessage( 'languageselector-setlang' )->text(),
			[ 'id' => 'languageselector-commit-' . $id, 'style' => $buttonstyle ] );
		$html .= Xml::closeElement( 'form' );
		$html .= Xml::closeElement( 'span' );

		return $html;
	}

	public static function onMenuSidebarAfterBuild( Skin $skin, &$bar ) {
		$lines = [];
		$code = $skin->getLanguage()->getCode();

		foreach ( self::getLanguageSelectorLanguages() as $ln ) {
			$lines[] = [
				$href = $skin->getTitle()->getFullURL( 'setlang=' . $ln ),
				'text' => Language::fetchLanguageName( $ln ),
				'href' => $href,
				'id' => 'n-languageselector',
				'active' => ( $code === $ln ),
			];
		}

		$bar['languageselector'] = $lines;

		return true;
	}
}