Track when (relevant) changes are made to <templatedata> tags

Bug: T267926
Change-Id: I55f72500b7bad7e648238560b516e870bc9130c8

.phan/stubs/eventlogging.php

@@ -0,0 +1,16 @@
+<?php
+
+class EventLogging {
+
+	/**
+	 * @param string $schemaName
+	 * @param int $revId
+	 * @param array $event
+	 * @param int $options
+	 * @return bool
+	 */
+	public static function logEvent( $schemaName, $revId, $event, $options = 0 ) {
+		return true;
+	}
+
+}

.phpcs.xml

@@ -6,4 +6,5 @@
 	<file>.</file>
 	<arg name="extensions" value="php" />
 	<arg name="encoding" value="UTF-8" />
+	<exclude-pattern>.phan/stubs</exclude-pattern>
 </ruleset>

extension.json

@@ -27,6 +27,7 @@
 		"ApiTemplateData": "includes/api/ApiTemplateData.php"
 	},
 	"Hooks": {
+		"EditPage::showEditForm:fields": "TemplateDataHooks::onEditPageShowEditFormFields",
 		"ParserFirstCallInit": "TemplateDataHooks::onParserFirstCallInit",
 		"PageContentSave": "TemplateDataHooks::onPageContentSave",
 		"ResourceLoaderRegisterModules": "TemplateDataHooks::onResourceLoaderRegisterModules",
@@ -217,7 +218,7 @@
 	"attributes": {
 		"EventLogging": {
 			"Schemas": {
-				"TemplateDataEditor": 20735408
+				"TemplateDataEditor": 20759032
 			}
 		},
 		"VisualEditor": {

includes/TemplateDataHooks.php

@@ -1,4 +1,7 @@
 <?php
+
+use MediaWiki\MediaWikiServices;
+
 /**
  * Hooks for TemplateData extension
  *
@@ -7,6 +10,19 @@
  */
 
 class TemplateDataHooks {
+
+	/**
+	 * @param EditPage $editPage
+	 * @param OutputPage $out
+	 */
+	public static function onEditPageShowEditFormFields( EditPage $editPage, OutputPage $out ) {
+		// TODO: Remove when not needed any more, see T267926
+		if ( $out->getRequest()->getBool( 'TemplateDataGeneratorUsed' ) ) {
+			// Recreate the dynamically created field after the user clicked "preview"
+			$out->addHTML( Html::hidden( 'TemplateDataGeneratorUsed', true ) );
+		}
+	}
+
 	/**
 	 * Register parser hooks
 	 * @param Parser $parser
@@ -67,16 +83,63 @@ class TemplateDataHooks {
 		// Specify format the same way the API and EditPage do to avoid extra parsing
 		$format = $content->getContentHandler()->getDefaultFormat();
 		$editInfo = $page->prepareContentForEdit( $content, null, $user, $format );
+		$parserOutput = $editInfo->getOutput();
 
-		$templateDataStatus = self::getStatusFromParserOutput( $editInfo->output );
+		$templateDataStatus = self::getStatusFromParserOutput( $parserOutput );
 		if ( $templateDataStatus instanceof Status && !$templateDataStatus->isOK() ) {
 			// Abort edit, show error message from TemplateDataBlob::getStatus
 			$status->merge( $templateDataStatus );
 			return false;
 		}
+
+		// TODO: Remove when not needed any more, see T267926
+		self::logChangeEvent( $page, $parserOutput->getProperty( 'templatedata' ), $user );
+
 		return true;
 	}
 
+	/**
+	 * @param WikiPage $page
+	 * @param string|false $newPageProperty
+	 * @param User $user
+	 */
+	private static function logChangeEvent( WikiPage $page, $newPageProperty, User $user ) {
+		if ( !ExtensionRegistry::getInstance()->isLoaded( 'EventLogging' ) ) {
+			return;
+		}
+
+		$services = MediaWikiServices::getInstance();
+		$title = $page->getTitle();
+		$pageId = $page->getId();
+		$props = $services->getPageProps()->getProperties( $title, 'templatedata' );
+		// The JSON strings here are guaranteed to be normalized (and possibly compressed) the same
+		// way. No need to normalize them again for this comparison.
+		if ( $newPageProperty === ( $props[$pageId] ?? false ) ) {
+			return;
+		}
+
+		$generatorUsed = RequestContext::getMain()->getRequest()->getBool( 'TemplateDataGeneratorUsed' );
+		$revision = $page->getRevisionRecord();
+
+		// Note: We know that irrelevant changes (e.g. whitespace changes) aren't logged here
+		EventLogging::logEvent(
+			'TemplateDataEditor',
+			// See https://meta.wikimedia.org/w/?oldid=20746997, keep in sync with extension.json!
+			20746997,
+			[
+				// Note: The "Done" button is disabled unless something changed, which means it's
+				// very likely (but not guaranteed) the generator was used to make the changes
+				'action' => $generatorUsed ? 'save-tag-edit-generator-used' : 'save-tag-edit-no-generator',
+				'page_id' => $pageId,
+				'page_namespace' => $title->getNamespace(),
+				'page_title' => $title->getText(),
+				'rev_id' => $revision ? $revision->getId() : 0,
+				'user_edit_count' => $user->getEditCount() ?? 0,
+				'user_id' => $user->getId(),
+			]
+		);
+	}
+
 	/**
 	 * Parser hook registering the GUI module only in edit pages.
 	 *

modules/ext.templateDataGenerator.editTemplatePage/Target.js

@@ -277,6 +277,16 @@ Target.prototype.onDialogApply = function ( templateData ) {
 			}
 		} );
 	}
+
+	// TODO: Remove when not needed any more, see T267926
+	// eslint-disable-next-line no-jquery/no-global-selector
+	if ( !$( 'input[name="TemplateDataGeneratorUsed"]' ).length ) {
+		$( '<input>' ).attr( {
+			type: 'hidden',
+			value: 1,
+			name: 'TemplateDataGeneratorUsed'
+		} ).insertAfter( '#wpTextbox1' );
+	}
 };
 
 module.exports = Target;