mediawiki-extensions-RelatedArticles/includes/Hooks.php

<?php

namespace RelatedArticles;

use MediaWiki\Extension\Disambiguator\Hooks as DisambiguatorHooks;
use MediaWiki\MediaWikiServices;
use OutputPage;
use Parser;
use ParserOutput;
use Skin;
use Title;
use User;

class Hooks {

	/**
	 * Handler for the <code>MakeGlobalVariablesScript</code> hook.
	 *
	 * Sets the value of the <code>wgRelatedArticles</code> global variable
	 * to the list of related articles in the cached parser output.
	 *
	 * @param array &$vars variables to be added into the output of OutputPage::headElement.
	 * @param OutputPage $out OutputPage instance calling the hook
	 */
	public static function onMakeGlobalVariablesScript( &$vars, OutputPage $out ) {
		$editorCuratedPages = $out->getProperty( 'RelatedArticles' );
		if ( $editorCuratedPages ) {
			$vars['wgRelatedArticles'] = $editorCuratedPages;
		}
	}

	/**
	 * Uses the Disambiguator extension to test whether the page is a disambiguation page.
	 *
	 * If the Disambiguator extension isn't installed, then the test always fails, i.e. the page is
	 * never a disambiguation page.
	 *
	 * @param Title $title
	 * @return bool
	 */
	private static function isDisambiguationPage( Title $title ) {
		return \ExtensionRegistry::getInstance()->isLoaded( 'Disambiguator' ) &&
			DisambiguatorHooks::isDisambiguationPage( $title );
	}

	/**
	 * Check whether the output page is a diff page
	 *
	 * @param OutputPage $out
	 * @return bool
	 */
	private static function isDiffPage( OutputPage $out ) {
		$request = $out->getRequest();
		$type = $request->getText( 'type' );
		$diff = $request->getText( 'diff' );
		$oldId = $request->getText( 'oldid' );
		$isSpecialMobileDiff = $out->getTitle()->isSpecial( 'MobileDiff' );

		return $type === 'revision' || $diff || $oldId || $isSpecialMobileDiff;
	}

	/**
	 * Is ReadMore allowed on skin?
	 *
	 * Some wikis may want to only enable the feature on some skins, so we'll only
	 * show it if the allow list (`RelatedArticlesFooterAllowedSkins`
	 * configuration variable) is empty or the skin is listed.
	 *
	 * @param User $user
	 * @param Skin $skin
	 * @return bool
	 */
	private static function isReadMoreAllowedOnSkin( User $user, Skin $skin ) {
		$config = MediaWikiServices::getInstance()->getConfigFactory()
			->makeConfig( 'RelatedArticles' );
		$skins = $config->get( 'RelatedArticlesFooterAllowedSkins' );
		$skinName = $skin->getSkinName();
		return empty( $skins ) || in_array( $skinName, $skins );
	}

	/**
	 * Can the page show related articles?
	 *
	 * @param Skin $skin
	 * @return bool
	 */
	private static function hasRelatedArticles( Skin $skin ): bool {
		$out = $skin->getOutput();
		$title = $out->getContext()->getTitle();
		$action = $out->getRequest()->getText( 'action', 'view' );
		return $title->inNamespace( NS_MAIN ) &&
			// T120735
			$action === 'view' &&
			!$title->isMainPage() &&
			$title->exists() &&
			!self::isDisambiguationPage( $title ) &&
			!self::isDiffPage( $out ) &&
			self::isReadMoreAllowedOnSkin( $out->getUser(), $out->getSkin() );
	}

	/**
	 * Handler for the <code>BeforePageDisplay</code> hook.
	 *
	 * Adds the <code>ext.relatedArticles.readMore.bootstrap</code> module
	 * to the output when:
	 *
	 * <ol>
	 *   <li>On mobile, the output is being rendered with
	 *     <code>SkinMinervaBeta<code></li>
	 *   <li>The page is in mainspace</li>
	 *   <li>The action is 'view'</li>
	 *   <li>The page is not the Main Page</li>
	 *   <li>The page is not a disambiguation page</li>
	 *   <li>The page is not a diff page</li>
	 *   <li>The feature is allowed on the skin (see isReadMoreAllowedOnSkin() above)</li>
	 * </ol>
	 *
	 * @param OutputPage $out The OutputPage object
	 * @param Skin $skin Skin object that will be used to generate the page
	 * @return bool Always <code>true</code>
	 */
	public static function onBeforePageDisplay( OutputPage $out, Skin $skin ) {
		if ( self::hasRelatedArticles( $skin ) ) {
			$out->addModules( [ 'ext.relatedArticles.readMore.bootstrap' ] );
			$out->addModuleStyles( [ 'ext.relatedArticles.styles' ] );
		}

		return true;
	}

	/**
	 * ResourceLoaderGetConfigVars hook handler for setting a config variable
	 * @see https://www.mediawiki.org/wiki/Manual:Hooks/ResourceLoaderGetConfigVars
	 *
	 * @param array &$vars Array of variables to be added into the output of the startup module.
	 * @return bool
	 */
	public static function onResourceLoaderGetConfigVars( &$vars ) {
		$config = MediaWikiServices::getInstance()->getConfigFactory()
			->makeConfig( 'RelatedArticles' );

		$limit = $config->get( 'RelatedArticlesCardLimit' );
		$vars['wgRelatedArticlesCardLimit'] = $limit;
		if ( $limit < 1 || $limit > 20 ) {
			throw new \RuntimeException(
				'The value of wgRelatedArticlesCardLimit is not valid. It should be between 1 and 20.'
			);
		}
		return true;
	}

	/**
	 * Handler for the <code>ParserFirstCallInit</code> hook.
	 *
	 * Registers the <code>related</code> parser function (see
	 * {@see Hooks::onFuncRelated}).
	 *
	 * @param Parser $parser Parser object
	 * @return bool Always <code>true</code>
	 */
	public static function onParserFirstCallInit( Parser $parser ) {
		$parser->setFunctionHook( 'related', 'RelatedArticles\\Hooks::onFuncRelated' );

		return true;
	}

	/**
	 * The <code>related</code> parser function.
	 *
	 * Appends the arguments to the internal list so that it can be used
	 * more that once per page.
	 * We don't use setProperty here is there is no need
	 * to store it as a page prop in the database, only in the cache.
	 *
	 * @todo Test for uniqueness
	 * @param Parser $parser Parser object
	 * @param string ...$args
	 *
	 * @return string Always <code>''</code>
	 */
	public static function onFuncRelated( Parser $parser, ...$args ) {
		$parserOutput = $parser->getOutput();
		$relatedPages = $parserOutput->getExtensionData( 'RelatedArticles' );
		if ( !$relatedPages ) {
			$relatedPages = [];
		}

		// Add all the related pages passed by the parser function
		// {{#related:Test with read more|Foo|Bar}}
		foreach ( $args as $relatedPage ) {
			$relatedPages[] = $relatedPage;
		}
		$parserOutput->setExtensionData( 'RelatedArticles', $relatedPages );

		return '';
	}

	/**
	 * Passes the related pages list from the cached parser output
	 * object to the output page for rendering.
	 *
	 * The list of related pages will be retrieved using
	 * <code>ParserOutput#getExtensionData</code>.
	 *
	 * @param OutputPage $out the OutputPage object
	 * @param ParserOutput $parserOutput ParserOutput object
	 * @return bool Always <code>true</code>
	 */
	public static function onOutputPageParserOutput( OutputPage $out, ParserOutput $parserOutput ) {
		$related = $parserOutput->getExtensionData( 'RelatedArticles' );

		if ( $related ) {
			$out->setProperty( 'RelatedArticles', $related );
		}

		return true;
	}

	/**
	 * Create container for ReadMore cards so that they're correctly placed in all skins.
	 *
	 * @param string &$data
	 * @param Skin $skin
	 */
	public static function onSkinAfterContent( &$data, Skin $skin ) {
		if ( self::hasRelatedArticles( $skin ) ) {
			$data .= \Html::element( 'div', [ 'class' => 'read-more-container' ] );
		}
	}
}