mediawiki-extensions-DiscussionTools/includes/Hooks/PageHooks.php

<?php
/**
 * DiscussionTools page hooks
 *
 * @file
 * @ingroup Extensions
 * @license MIT
 */

namespace MediaWiki\Extension\DiscussionTools\Hooks;

use Html;
use IContextSource;
use MediaWiki\Actions\Hook\GetActionNameHook;
use MediaWiki\Extension\DiscussionTools\CommentFormatter;
use MediaWiki\Extension\DiscussionTools\SubscriptionStore;
use MediaWiki\Hook\BeforePageDisplayHook;
use MediaWiki\Hook\OutputPageBeforeHTMLHook;
use MediaWiki\MediaWikiServices;
use OutputPage;
use Skin;
use VisualEditorHooks;

class PageHooks implements
	BeforePageDisplayHook,
	GetActionNameHook,
	OutputPageBeforeHTMLHook
{
	/** @var SubscriptionStore */
	protected $subscriptionStore;

	/**
	 * @param SubscriptionStore $subscriptionStore
	 */
	public function __construct( SubscriptionStore $subscriptionStore ) {
		$this->subscriptionStore = $subscriptionStore;
	}

	/**
	 * Adds DiscussionTools JS to the output.
	 *
	 * This is attached to the MediaWiki 'BeforePageDisplay' hook.
	 *
	 * @param OutputPage $output
	 * @param Skin $skin
	 * @return void This hook must not abort, it must return no value
	 */
	public function onBeforePageDisplay( $output, $skin ): void {
		$user = $output->getUser();
		// Load style modules if the tools can be available for the title
		// as this means the DOM may have been modified in the parser cache.
		if ( HookUtils::isAvailableForTitle( $output->getTitle() ) ) {
			$output->addModuleStyles( [
				'ext.discussionTools.init.styles',
			] );
		}
		// Load modules if any DT feature is enabled for this user
		if ( HookUtils::isFeatureEnabledForOutput( $output ) ) {
			$output->addModules( [
				'ext.discussionTools.init'
			] );

			$enabledVars = [];
			foreach ( HookUtils::FEATURES as $feature ) {
				$enabledVars[$feature] = HookUtils::isFeatureEnabledForOutput( $output, $feature );
			}
			$output->addJsConfigVars( 'wgDiscussionToolsFeaturesEnabled', $enabledVars );

			$services = MediaWikiServices::getInstance();
			$optionsLookup = $services->getUserOptionsLookup();
			$req = $output->getRequest();
			$editor = $optionsLookup->getOption( $user, 'discussiontools-editmode' );
			// User has no preferred editor yet
			// If the user has a preferred editor, this will be evaluated in the client
			if ( !$editor ) {
				// Check which editor we would use for articles
				// VE pref is 'visualeditor'/'wikitext'. Here we describe the mode,
				// not the editor, so 'visual'/'source'
				$editor = VisualEditorHooks::getPreferredEditor( $user, $req ) === 'visualeditor' ?
					'visual' : 'source';
				$output->addJsConfigVars(
					'wgDiscussionToolsFallbackEditMode',
					$editor
				);
			}
			$dtConfig = $services->getConfigFactory()->makeConfig( 'discussiontools' );
			$abstate = $dtConfig->get( 'DiscussionToolsABTest' ) ?
				$optionsLookup->getOption( $user, 'discussiontools-abtest' ) :
				false;
			if ( $abstate ) {
				$output->addJsConfigVars(
					'wgDiscussionToolsABTestBucket',
					$abstate
				);
			}
		}

		// Replace the action=edit&section=new form with the new topic tool.
		if ( HookUtils::shouldUseNewTopicTool( $output->getContext() ) ) {
			$output->addJsConfigVars( 'wgDiscussionToolsStartNewTopicTool', true );

			// For no-JS compatibility, redirect to the old new section editor if JS is unavailable.
			// This isn't great, because the user has to load the page twice. But making a page that is
			// both a view mode and an edit mode seems difficult, so I'm cutting some corners here.
			// (Code below adapted from VisualEditor.)
			$params = $output->getRequest()->getValues();
			$params['dtenable'] = '0';
			$url = wfScript() . '?' . wfArrayToCgi( $params );
			$escapedUrl = htmlspecialchars( $url );

			// Redirect if the user has no JS (<noscript>)
			$output->addHeadItem(
				'dt-noscript-fallback',
				"<noscript><meta http-equiv=\"refresh\" content=\"0; url=$escapedUrl\"></noscript>"
			);
			// Redirect if the user has no ResourceLoader
			$output->addScript( Html::inlineScript(
				"(window.NORLQ=window.NORLQ||[]).push(" .
					"function(){" .
						"location.href=\"$url\";" .
					"}" .
				");"
			) );
		}
	}

	/**
	 * OutputPageBeforeHTML hook handler
	 * @see https://www.mediawiki.org/wiki/Manual:Hooks/OutputPageBeforeHTML
	 *
	 * @param OutputPage $output OutputPage object that corresponds to the page
	 * @param string &$text Text that will be displayed, in HTML
	 * @return bool|void This hook must not abort, it must return true or null.
	 */
	public function onOutputPageBeforeHTML( $output, &$text ) {
		$lang = $output->getLanguage();
		// Check after the parser cache if tools need to be added for
		// non-cacheable reasons i.e. query string or cookie
		// The addDiscussionTools method is responsible for ensuring that
		// tools aren't added twice.
		foreach ( CommentFormatter::USE_WITH_FEATURES as $feature ) {
			if ( HookUtils::isFeatureEnabledForOutput( $output, $feature ) ) {
				CommentFormatter::addDiscussionTools( $text );
				break;
			}
		}

		foreach ( HookUtils::FEATURES as $feature ) {
			// Add a CSS class for each enabled feature
			if ( HookUtils::isFeatureEnabledForOutput( $output, $feature ) ) {
				$output->addBodyClasses( "ext-discussiontools-$feature-enabled" );
			}
		}

		if ( HookUtils::isFeatureEnabledForOutput( $output, HookUtils::TOPICSUBSCRIPTION ) ) {
			$text = CommentFormatter::postprocessTopicSubscription(
				$text, $lang, $this->subscriptionStore, $output->getUser()
			);
		}
		if ( HookUtils::isFeatureEnabledForOutput( $output, HookUtils::REPLYTOOL ) ) {
			$text = CommentFormatter::postprocessReplyTool(
				$text, $lang
			);
		}

		return true;
	}

	/**
	 * GetActionName hook handler
	 *
	 * @param IContextSource $context Request context
	 * @param string &$action Default action name, reassign to change it
	 * @return void This hook must not abort, it must return no value
	 */
	public function onGetActionName( IContextSource $context, string &$action ): void {
		if ( $action === 'edit' && HookUtils::shouldUseNewTopicTool( $context ) ) {
			$action = 'view';
		}
	}
}