Sync: Introduce helper function and CPT for Activity Log entries

projects/packages/sync/changelog/add-sync-custom-post-types-for-activity-log

@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+Allow an Activity Log specific custom post type, plus a helper function to simplify adding entries. 

projects/packages/sync/src/class-actions.php

@@ -126,6 +126,9 @@ public static function init() {
 		// Sync connected user role changes to WordPress.com.
 		Users::init();
 
+		// Activity Log custom events.
+		Activity_Log_Event::init();
+
 		// Publicize filter to prevent publicizing blacklisted post types.
 		add_filter( 'publicize_should_publicize_published_post', array( __CLASS__, 'prevent_publicize_blacklisted_posts' ), 10, 2 );
 

projects/packages/sync/src/class-activity-log-event.php

@@ -0,0 +1,255 @@
+<?php
+/**
+ * Activity Log custom event support.
+ *
+ * @package automattic/jetpack-sync
+ */
+
+namespace Automattic\Jetpack\Sync;
+
+/**
+ * Handles Activity Log custom event creation and validation.
+ */
+class Activity_Log_Event {
+
+	/**
+	 * Post type name for Activity Log custom entries.
+	 */
+	const POST_TYPE = 'jp_act_log_event';
+
+	/**
+	 * Default event severity.
+	 */
+	const DEFAULT_SEVERITY = 'info';
+
+	/**
+	 * Allowed event severities.
+	 */
+	const ALLOWED_SEVERITIES = array(
+		'info'    => true,
+		'success' => true,
+		'warning' => true,
+		'error'   => true,
+	);
+
+	/**
+	 * Maximum title length.
+	 */
+	const MAX_TITLE_LENGTH = 200;
+
+	/**
+	 * Maximum content length.
+	 */
+	const MAX_CONTENT_LENGTH = 5000;
+
+	/**
+	 * Maximum source length.
+	 */
+	const MAX_SOURCE_LENGTH = 100;
+
+	/**
+	 * Initialize Activity Log custom event hooks.
+	 */
+	public static function init() {
+		add_action( 'init', array( __CLASS__, 'register_post_type' ) );
+		add_filter( 'publicize_should_publicize_published_post', array( __CLASS__, 'prevent_publicize' ), 10, 2 );
+		add_filter( 'jetpack_sitemap_post_types', array( __CLASS__, 'filter_sitemap_post_types' ) );
+	}
+
+	/**
+	 * Registers the Activity Log CPT with hardened defaults that prevent leakage
+	 * to front-end queries, RSS, REST, search, sitemaps, and exports.
+	 */
+	public static function register_post_type() {
+		register_post_type(
+			self::POST_TYPE,
+			array(
+				'labels'              => array(
+					'name'          => __( 'Activity Log Events', 'jetpack-sync' ),
+					'singular_name' => __( 'Activity Log Event', 'jetpack-sync' ),
+				),
+				'public'              => false,
+				'publicly_queryable'  => false,
+				'show_ui'             => false,
+				'show_in_menu'        => false,
+				'show_in_nav_menus'   => false,
+				'show_in_rest'        => false,
+				'show_in_admin_bar'   => false,
+				'exclude_from_search' => true,
+				'has_archive'         => false,
+				'rewrite'             => false,
+				'query_var'           => false,
+				'can_export'          => false,
+				'supports'            => array( 'title', 'editor' ),
+			)
+		);
+	}
+
+	/**
+	 * Logs a custom event to the Jetpack Activity Log.
+	 *
+	 * Call this on or after the `init` action so the Activity Log post type and Sync listeners are registered.
+	 *
+	 * @param array $args {
+	 *     Activity log event arguments.
+	 *
+	 *     @type string $title       Required. Plain-text title, truncated to 200 chars.
+	 *     @type string $content     Required. Plain-text body, truncated to 5000 chars.
+	 *     @type string $source      Optional. Identifier for the source of the event, e.g. 'mc'.
+	 *     @type string $severity    Optional. 'info', 'success', 'warning', or 'error'. Defaults to 'info'.
+	 * }
+	 * @return int|false Post ID on success, false if validation fails.
+	 */
+	public static function create( array $args ) {
+		$payload = self::build_payload( $args );
+		if ( false === $payload ) {
+			return false;
+		}
+
+		$post_id = wp_insert_post(
+			wp_slash(
+				array(
+					'post_type'    => self::POST_TYPE,
+					'post_title'   => $payload['title'],
+					'post_content' => wp_json_encode( $payload, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE ),
+					'post_status'  => 'publish',
+				)
+			),
+			true
+		);
+
+		return is_wp_error( $post_id ) ? false : $post_id;
+	}
+
+	/**
+	 * Checks that an Activity Log custom event has the minimum payload shape before enqueueing it for sync,
+	 * in case data bypasses the Activity_Log_Event::create() helper.
+	 *
+	 * @param \WP_Post $post Activity Log post.
+	 * @return bool
+	 */
+	public static function is_valid_post( $post ) {
+		if ( ! $post instanceof \WP_Post || self::POST_TYPE !== $post->post_type ) {
+			return false;
+		}
+
+		$data = json_decode( $post->post_content, true );
+		if ( ! is_array( $data ) ) {
+			$data = json_decode( wp_unslash( $post->post_content ), true );
+		}
+
+		if ( ! is_array( $data ) ) {
+			return false;
+		}
+
+		foreach ( array( 'title', 'content' ) as $field ) {
+			if (
+				! isset( $data[ $field ] )
+				|| is_array( $data[ $field ] )
+				|| is_object( $data[ $field ] )
+				|| '' === trim( (string) $data[ $field ] )
+			) {
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	 * Never auto-share Activity Log entries via Jetpack Social,
+	 * even if a third party adds 'publicize' post-type support to this CPT.
+	 *
+	 * @param bool     $should_publicize Publicize status prior to this filter running.
+	 * @param \WP_Post $post             The post to test for Publicizability.
+	 * @return bool
+	 */
+	public static function prevent_publicize( $should_publicize, $post ) {
+		return ( $post && self::POST_TYPE === $post->post_type ) ? false : $should_publicize;
+	}
+
+	/**
+	 * Never include Activity Log entries in Jetpack sitemaps,
+	 * even if a third party adds this CPT to the sitemap post-type list.
+	 *
+	 * @param string[] $types Sitemap post types.
+	 * @return string[]
+	 */
+	public static function filter_sitemap_post_types( $types ) {
+		return array_values( array_diff( (array) $types, array( self::POST_TYPE ) ) );
+	}
+
+	/**
+	 * Builds an Activity Log event payload from raw input.
+	 *
+	 * @param array $args Raw event arguments.
+	 * @return array|false Sanitized payload, or false if validation fails.
+	 */
+	private static function build_payload( array $args ) {
+		$title   = self::sanitize_string( $args['title'] ?? '', self::MAX_TITLE_LENGTH );
+		$content = self::sanitize_string( $args['content'] ?? '', self::MAX_CONTENT_LENGTH );
+
+		if ( '' === $title || '' === $content ) {
+			return false;
+		}
+
+		$severity = self::sanitize_severity( $args['severity'] ?? self::DEFAULT_SEVERITY );
+		if ( false === $severity ) {
+			return false;
+		}
+
+		$payload = array(
+			'title'    => $title,
+			'content'  => $content,
+			'severity' => $severity,
+		);
+
+		$source = self::sanitize_string( $args['source'] ?? '', self::MAX_SOURCE_LENGTH );
+		if ( '' !== $source ) {
+			$payload['source'] = $source;
+		}
+
+		return $payload;
+	}
+
+	/**
+	 * Strips HTML/PHP from a value and truncates it to a maximum character length, multibyte-safe.
+	 *
+	 * @param mixed $value Raw value.
+	 * @param int   $max   Maximum length in characters.
+	 * @return string
+	 */
+	private static function sanitize_string( $value, $max ) {
+		if ( is_array( $value ) || is_object( $value ) ) {
+			return '';
+		}
+
+		$value = wp_strip_all_tags( (string) $value, true );
+		$value = trim( preg_replace( '/[^\P{C}\t\r\n]/u', '', $value ) );
+
+		if ( function_exists( 'mb_substr' ) ) {
+			return mb_substr( $value, 0, $max );
+		}
+
+		return substr( $value, 0, $max );
+	}
+
+	/**
+	 * Sanitizes an Activity Log severity value.
+	 *
+	 * @param mixed $severity Raw severity.
+	 * @return string|false Sanitized severity, or false if invalid.
+	 */
+	private static function sanitize_severity( $severity ) {
+		if ( is_array( $severity ) || is_object( $severity ) ) {
+			return false;
+		}
+
+		$severity = strtolower( trim( (string) $severity ) );
+		if ( '' === $severity ) {
+			return self::DEFAULT_SEVERITY;
+		}
+
+		return isset( self::ALLOWED_SEVERITIES[ $severity ] ) ? $severity : false;
+	}
+}

projects/packages/sync/src/modules/class-posts.php

@@ -9,6 +9,7 @@
 
 use Automattic\Jetpack\Constants as Jetpack_Constants;
 use Automattic\Jetpack\Roles;
+use Automattic\Jetpack\Sync\Activity_Log_Event;
 use Automattic\Jetpack\Sync\Modules;
 use Automattic\Jetpack\Sync\Settings;
 
@@ -500,6 +501,11 @@ public function filter_jetpack_sync_before_enqueue_jetpack_published_post( $args
 		}
 
 		list( $post_id, $flags, $post ) = $args;
+
+		if ( Activity_Log_Event::POST_TYPE === $post->post_type && ! Activity_Log_Event::is_valid_post( $post ) ) {
+			return false;
+		}
+
 		return array( (int) $post_id, $flags, $this->filter_post_content_and_add_links( $post ) );
 	}