Current File : /home/jvzmxxx/wiki/extensions/Wikibase/repo/includes/Hooks/LinkBeginHookHandler.php

<?php

namespace Wikibase\Repo\Hooks;

use Action;
use DummyLinker;
use Language;
use Linker;
use RequestContext;
use SpecialPageFactory;
use Title;
use Wikibase\DataModel\Services\Lookup\TermLookup;
use Wikibase\LanguageFallbackChain;
use Wikibase\Lib\Store\StorageException;
use Wikibase\Repo\EntityNamespaceLookup;
use Wikibase\Repo\WikibaseRepo;
use Wikibase\Store\EntityIdLookup;

/**
 * Handler for the LinkBegin hook, used to change the default link text of links to wikibase Entity
 * pages to the respective entity's label. This is used mainly for listings on special pages or for
 * edit summaries, where it is useful to see pages listed by label rather than their entity ID.
 *
 * Label lookups are relatively expensive if done repeatedly for individual labels. If possible,
 * labels should be pre-loaded and buffered for later use via the LinkBegin hook.
 *
 * @see LabelPrefetchHookHandlers
 *
 * @since 0.5
 *
 * @license GPL-2.0+
 * @author Katie Filbert < aude.wiki@gmail.com >
 */
class LinkBeginHookHandler {

	/**
	 * @var EntityIdLookup
	 */
	private $entityIdLookup;

	/**
	 * @var TermLookup
	 */
	private $termLookup;

	/**
	 * @var EntityNamespaceLookup
	 */
	private $entityNamespaceLookup;

	/**
	 * @var LanguageFallbackChain
	 */
	private $languageFallback;

	/**
	 * @var Language
	 */
	private $pageLanguage;

	/**
	 * @return self
	 */
	private static function newFromGlobalState() {
		$wikibaseRepo = WikibaseRepo::getDefaultInstance();
		$languageFallbackChainFactory = $wikibaseRepo->getLanguageFallbackChainFactory();
		// NOTE: keep in sync with fallback chain construction in LabelPrefetchHookHandler::newFromGlobalState
		$context = RequestContext::getMain();
		$languageFallbackChain = $languageFallbackChainFactory->newFromContext( $context );

		return new self(
			$wikibaseRepo->getEntityIdLookup(),
			$wikibaseRepo->getTermLookup(),
			$wikibaseRepo->getEntityNamespaceLookup(),
			$languageFallbackChain,
			$context->getLanguage()
		);
	}

	/**
	 * Special page handling where we want to display meaningful link labels instead of just the items ID.
	 * This is only handling special pages right now and gets disabled in normal pages.
	 * @see https://www.mediawiki.org/wiki/Manual:Hooks/LinkBegin
	 *
	 * @param DummyLinker $skin
	 * @param Title $target
	 * @param string $html
	 * @param array $customAttribs
	 * @param string $query
	 * @param array $options
	 * @param mixed $ret
	 * @return bool true
	 */
	public static function onLinkBegin( $skin, $target, &$html, array &$customAttribs, &$query,
		&$options, &$ret
	) {
		$context = RequestContext::getMain();
		if ( !$context->hasTitle() ) {
			// Short-circuit this hook if no title is
			// set in the main context (T131176)
			return true;
		}

		$handler = self::newFromGlobalState();
		$handler->doOnLinkBegin( $target, $html, $customAttribs, $context );

		return true;
	}

	/**
	 * @param EntityIdLookup $entityIdLookup
	 * @param TermLookup $termLookup
	 * @param EntityNamespaceLookup $entityNamespaceLookup
	 * @param LanguageFallbackChain $languageFallback
	 * @param Language $pageLanguage
	 *
	 * @todo: Would be nicer to take a LabelDescriptionLookup instead of TermLookup + FallbackChain.
	 */
	public function __construct(
		EntityIdLookup $entityIdLookup,
		TermLookup $termLookup,
		EntityNamespaceLookup $entityNamespaceLookup,
		LanguageFallbackChain $languageFallback,
		Language $pageLanguage
	) {
		$this->entityIdLookup = $entityIdLookup;
		$this->termLookup = $termLookup;
		$this->entityNamespaceLookup = $entityNamespaceLookup;
		$this->languageFallback = $languageFallback;
		$this->pageLanguage = $pageLanguage;
	}

	/**
	 * @param Title $target
	 * @param string &$html
	 * @param array &$customAttribs
	 * @param RequestContext $context
	 */
	public function doOnLinkBegin( Title $target, &$html, array &$customAttribs, RequestContext $context ) {
		$out = $context->getOutput();

		if ( !$this->entityNamespaceLookup->isEntityNamespace( $target->getNamespace() ) ) {
			return;
		}

		// Only continue on pages with edit summaries (histories / diffs) or on special pages.
		// Don't run this code when accessing it through the api (eg. for parsing) as the title is
		// set to a special page dummy in api.php, see https://phabricator.wikimedia.org/T111346
		if ( defined( 'MW_API' ) || !$this->shouldConvert( $out->getTitle(), $context ) ) {
			return;
		}

		$targetText = $target->getText();

		// Handle "fake" titles for new entities as generated by
		// EditEntity::getContextForEditFilter(). For instance, a link to Property:NewProperty
		// would be replaced by a link to Special:NewProperty. This is useful in logs,
		// to indicate that the logged action occurred while creating an entity.
		if ( SpecialPageFactory::exists( $targetText ) ) {
			$target = Title::makeTitle( NS_SPECIAL, $targetText );
			$html = Linker::linkKnown( $target );

			return;
		}

		if ( !$target->exists() ) {
			// The link points to a non-existing item.
			return;
		}

		// if custom link text is given, there is no point in overwriting it
		// but not if it is similar to the plain title
		if ( $html !== null && $target->getFullText() !== $html ) {
			return;
		}

		$entityId = $this->entityIdLookup->getEntityIdForTitle( $target );

		if ( !$entityId ) {
			return;
		}

		// @todo: this re-implements the logic in LanguageFallbackLabelDescriptionLookup,
		// as that didn't support descriptions back when this code was written.

		// NOTE: keep in sync with with fallback languages in LabelPrefetchHookHandler::newFromGlobalState

		try {
			$labels = $this->termLookup->getLabels( $entityId, $this->languageFallback->getFetchLanguageCodes() );
			$descriptions = $this->termLookup->getDescriptions( $entityId, $this->languageFallback->getFetchLanguageCodes() );
		} catch ( StorageException $ex ) {
			// This shouldn't happen if $target->exists() return true!
			return;
		}

		$labelData = $this->getPreferredTerm( $labels );
		$descriptionData = $this->getPreferredTerm( $descriptions );

		$html = $this->getHtml( $target, $labelData );

		$customAttribs['title'] = $this->getTitleAttribute(
			$target,
			$labelData,
			$descriptionData
		);

		// add wikibase styles in all cases, so we can format the link properly:
		$out->addModuleStyles( array( 'wikibase.common' ) );
	}

	/**
	 * @param array $termsByLanguage
	 *
	 * @return string[]|null
	 */
	private function getPreferredTerm( array $termsByLanguage ) {
		if ( empty( $termsByLanguage ) ) {
			return null;
		}

		return $this->languageFallback->extractPreferredValueOrAny(
			$termsByLanguage
		);
	}

	/**
	 * Whether we should try to convert links on this page.
	 * This caches that result within a static variable,
	 * thus it can't change (except in phpunit tests).
	 *
	 * @param Title|null $currentTitle
	 * @param RequestContext $context
	 * @return bool
	 */
	private function shouldConvert( Title $currentTitle = null, RequestContext $context ) {
		static $shouldConvert = null;
		if ( $shouldConvert !== null && !defined( 'MW_PHPUNIT_TEST' ) ) {
			return $shouldConvert;
		}

		$actionName = Action::getActionName( $context );
		 // This is how Article detects diffs
		$isDiff = $actionName === 'view' && $context->getRequest()->getCheck( 'diff' );

		// Only continue on pages with edit summaries (histories / diffs) or on special pages.
		if (
			( $currentTitle === null || !$currentTitle->isSpecialPage() )
			&& $actionName !== 'history'
			&& !$isDiff
		) {
			// Note: this may not work right with special page transclusion. If $out->getTitle()
			// doesn't return the transcluded special page's title, the transcluded text will
			// not have entity IDs resolved to labels.
			$shouldConvert = false;
			return false;
		}

		$shouldConvert = true;
		return true;
	}

	/**
	 * @param string[]|null $termData A term record as returned by
	 * LanguageFallbackChain::extractPreferredValueOrAny(),
	 * containing the 'value' and 'language' fields, or null
	 * or an empty array.
	 *
	 * @see LanguageFallbackChain::extractPreferredValueOrAny
	 *
	 * @return array list( string $text, Language $language )
	 */
	private function extractTextAndLanguage( array $termData = null ) {
		if ( $termData ) {
			return array(
				$termData['value'],
				Language::factory( $termData['language'] )
			);
		} else {
			return array(
				'',
				$this->pageLanguage
			);
		}
	}

	private function getHtml( Title $title, array $labelData = null ) {
		/** @var Language $labelLang */
		list( $labelText, $labelLang ) = $this->extractTextAndLanguage( $labelData );

		$idHtml = '<span class="wb-itemlink-id">'
			. wfMessage(
				'wikibase-itemlink-id-wrapper',
				$title->getText()
			)->inContentLanguage()->escaped()
			. '</span>';

		$labelHtml = '<span class="wb-itemlink-label"'
				. ' lang="' . htmlspecialchars( $labelLang->getHtmlCode() ) . '"'
				. ' dir="' . htmlspecialchars( $labelLang->getDir() ) . '">'
			. htmlspecialchars( $labelText )
			. '</span>';

		return '<span class="wb-itemlink">'
			. wfMessage( 'wikibase-itemlink' )->rawParams(
				$labelHtml,
				$idHtml
			)->inContentLanguage()->escaped()
			. '</span>';
	}

	private function getTitleAttribute( Title $title, array $labelData = null, array $descriptionData = null ) {
		/** @var Language $labelLang */
		/** @var Language $descriptionLang */

		list( $labelText, $labelLang ) = $this->extractTextAndLanguage( $labelData );
		list( $descriptionText, $descriptionLang ) = $this->extractTextAndLanguage( $descriptionData );

		// Set title attribute for constructed link, and make tricks with the directionality to get it right
		$titleText = ( $labelText !== '' )
			? $labelLang->getDirMark() . $labelText
				. $this->pageLanguage->getDirMark()
			: $title->getPrefixedText();

		$descriptionText = $descriptionLang->getDirMark() . $descriptionText
			. $this->pageLanguage->getDirMark();

		return ( $descriptionText !== '' ) ?
			wfMessage(
				'wikibase-itemlink-title',
				$titleText,
				$descriptionText
			)->inContentLanguage()->text() :
			$titleText; // no description, just display the title then
	}

}