Add Attachments processor class for handling ActivityPub media

.github/changelog/2311-from-description

@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+Added a new ap_object post type and taxonomies for storing and managing incoming ActivityPub objects, with updated handlers

includes/class-attachments.php

@@ -0,0 +1,258 @@
+<?php
+/**
+ * Attachments processing file.
+ *
+ * @package Activitypub
+ */
+
+namespace Activitypub;
+
+/**
+ * Attachments processor class.
+ */
+class Attachments {
+
+	/**
+	 * Process attachments from an ActivityPub object and attach them to a post.
+	 *
+	 * @param array $attachments Array of ActivityPub attachment objects.
+	 * @param int   $post_id     The post ID to attach files to.
+	 * @param int   $author_id   Optional. User ID to set as attachment author. Default 0.
+	 *
+	 * @return array Array of attachment IDs.
+	 */
+	public static function process( $attachments, $post_id, $author_id = 0 ) {
+		if ( empty( $attachments ) || ! is_array( $attachments ) ) {
+			return array();
+		}
+
+		$attachment_ids = array();
+		foreach ( $attachments as $attachment ) {
+			$attachment_data = self::normalize_attachment( $attachment );
+
+			if ( empty( $attachment_data['url'] ) ) {
+				continue;
+			}
+
+			$attachment_id = self::save_attachment( $attachment_data, $post_id, $author_id );
+
+			if ( ! \is_wp_error( $attachment_id ) ) {
+				$attachment_ids[] = $attachment_id;
+			}
+		}
+
+		// Append media markup to post content.
+		if ( ! empty( $attachment_ids ) ) {
+			self::append_media_to_content( $post_id, $attachment_ids );
+		}
+
+		return $attachment_ids;
+	}
+
+	/**
+	 * Normalize an ActivityPub attachment object to a standard format.
+	 *
+	 * @param mixed $attachment The attachment data (array or object).
+	 *
+	 * @return array|false Normalized attachment data or false on failure.
+	 */
+	private static function normalize_attachment( $attachment ) {
+		// Convert object to array if needed.
+		if ( is_object( $attachment ) ) {
+			$attachment = get_object_vars( $attachment );
+		}
+
+		if ( ! is_array( $attachment ) || empty( $attachment['url'] ) ) {
+			return false;
+		}
+
+		return array(
+			'url'       => $attachment['url'],
+			'mediaType' => $attachment['mediaType'] ?? '',
+			'name'      => $attachment['name'] ?? '',
+			'type'      => $attachment['type'] ?? 'Document',
+		);
+	}
+
+	/**
+	 * Save an attachment (local file or remote URL) to the media library.
+	 *
+	 * @param array $attachment_data The normalized attachment data.
+	 * @param int   $post_id         The post ID to attach to.
+	 * @param int   $author_id       Optional. User ID to set as attachment author. Default 0.
+	 *
+	 * @return int|\WP_Error The attachment ID or WP_Error on failure.
+	 */
+	private static function save_attachment( $attachment_data, $post_id, $author_id = 0 ) {
+		$is_local = ! preg_match( '#^https?://#i', $attachment_data['url'] );
+
+		if ( $is_local ) {
+			// Read local file from disk.
+			\WP_Filesystem();
+			global $wp_filesystem;
+
+			if ( ! $wp_filesystem->exists( $attachment_data['url'] ) ) {
+				/* translators: %s: file path */
+				return new \WP_Error( 'file_not_found', sprintf( \__( 'File not found: %s', 'activitypub' ), $attachment_data['url'] ) );
+			}
+
+			// Copy to temp file so media_handle_sideload doesn't move the original.
+			$tmp_file = \wp_tempnam( \basename( $attachment_data['url'] ) );
+			$wp_filesystem->copy( $attachment_data['url'], $tmp_file, true );
+		} else {
+			// Download remote URL.
+			$tmp_file = \download_url( $attachment_data['url'] );
+
+			if ( \is_wp_error( $tmp_file ) ) {
+				return $tmp_file;
+			}
+		}
+
+		// Prepare file array for WordPress.
+		$file_array = array(
+			'name'     => \basename( $attachment_data['url'] ),
+			'tmp_name' => $tmp_file,
+		);
+
+		// Prepare attachment post data.
+		$post_data = array(
+			'post_mime_type' => $attachment_data['mediaType'] ?? '',
+			'post_title'     => $attachment_data['name'] ?? '',
+			'post_content'   => $attachment_data['name'] ?? '',
+			'post_status'    => 'inherit',
+			'post_author'    => $author_id,
+			'meta_input'     => array(
+				'_activitypub_source_url' => $attachment_data['url'],
+			),
+		);
+
+		// Add alt text for images.
+		if ( ! empty( $attachment_data['name'] ) ) {
+			$mime_type = $attachment_data['mediaType'] ?? '';
+			if ( 'image' === strtok( $mime_type, '/' ) ) {
+				$post_data['meta_input']['_wp_attachment_image_alt'] = $attachment_data['name'];
+			}
+		}
+
+		// Ensure required WordPress functions are loaded.
+		if ( ! function_exists( 'media_handle_sideload' ) ) {
+			require_once ABSPATH . 'wp-admin/includes/media.php';
+			require_once ABSPATH . 'wp-admin/includes/file.php';
+			require_once ABSPATH . 'wp-admin/includes/image.php';
+		}
+
+		// Sideload the attachment into WordPress.
+		$attachment_id = \media_handle_sideload( $file_array, $post_id, '', $post_data );
+
+		// Clean up temp file if there was an error.
+		if ( \is_wp_error( $attachment_id ) ) {
+			\wp_delete_file( $tmp_file );
+		}
+
+		return $attachment_id;
+	}
+
+	/**
+	 * Append media to post content.
+	 *
+	 * @param int   $post_id        The post ID.
+	 * @param array $attachment_ids Array of attachment IDs.
+	 */
+	private static function append_media_to_content( $post_id, $attachment_ids ) {
+		$post = \get_post( $post_id );
+		if ( ! $post ) {
+			return;
+		}
+
+		$media     = self::generate_media_markup( $attachment_ids );
+		$separator = "\n\n";
+
+		// Don't add separator if content is empty.
+		if ( empty( trim( $post->post_content ) ) ) {
+			$separator = '';
+		}
+
+		\wp_update_post(
+			array(
+				'ID'           => $post_id,
+				'post_content' => $post->post_content . $separator . $media,
+			)
+		);
+	}
+
+	/**
+	 * Generate media markup for attachments.
+	 *
+	 * @param array $attachment_ids Array of attachment IDs.
+	 *
+	 * @return string The generated markup.
+	 */
+	private static function generate_media_markup( $attachment_ids ) {
+		if ( empty( $attachment_ids ) ) {
+			return '';
+		}
+
+		/**
+		 * Filters the media markup for ActivityPub attachments.
+		 *
+		 * Allows plugins to provide custom markup for attachments.
+		 * If this filter returns a non-empty string, it will be used instead of
+		 * the default block markup.
+		 *
+		 * @param string $markup         The custom markup. Default empty string.
+		 * @param array  $attachment_ids Array of attachment IDs.
+		 */
+		$custom_markup = \apply_filters( 'activitypub_attachments_media_markup', '', $attachment_ids );
+
+		if ( ! empty( $custom_markup ) ) {
+			return $custom_markup;
+		}
+
+		// Default to block markup.
+		$type = strtok( \get_post_mime_type( $attachment_ids[0] ), '/' );
+
+		// Single video or audio file.
+		if ( 1 === \count( $attachment_ids ) && ( 'video' === $type || 'audio' === $type ) ) {
+			return sprintf(
+				'<!-- wp:%1$s {"id":"%2$s"} --><figure class="wp-block-%1$s"><%1$s controls src="%3$s"></%1$s></figure><!-- /wp:%1$s -->',
+				\esc_attr( $type ),
+				\esc_attr( $attachment_ids[0] ),
+				\esc_url( \wp_get_attachment_url( $attachment_ids[0] ) )
+			);
+		}
+
+		// Multiple attachments or images: use gallery block.
+		return self::get_gallery_block( $attachment_ids );
+	}
+
+	/**
+	 * Get gallery block markup.
+	 *
+	 * @param array $attachment_ids The attachment IDs to use.
+	 *
+	 * @return string The gallery block markup.
+	 */
+	private static function get_gallery_block( $attachment_ids ) {
+		$gallery  = '<!-- wp:gallery {"ids":[' . \implode( ',', $attachment_ids ) . '],"linkTo":"none"} -->' . "\n";
+		$gallery .= '<figure class="wp-block-gallery has-nested-images columns-default is-cropped">';
+
+		foreach ( $attachment_ids as $id ) {
+			$image_src = \wp_get_attachment_image_src( $id, 'large' );
+			if ( ! $image_src ) {
+				continue;
+			}
+
+			$caption  = \get_post_field( 'post_content', $id );
+			$gallery .= "\n<!-- wp:image {\"id\":{$id},\"sizeSlug\":\"large\",\"linkDestination\":\"none\"} -->\n";
+			$gallery .= '<figure class="wp-block-image size-large">';
+			$gallery .= '<img src="' . \esc_url( $image_src[0] ) . '" alt="' . \esc_attr( $caption ) . '" class="' . \esc_attr( 'wp-image-' . $id ) . '"/>';
+			$gallery .= '</figure>';
+			$gallery .= "\n<!-- /wp:image -->\n";
+		}
+
+		$gallery .= "</figure>\n";
+		$gallery .= '<!-- /wp:gallery -->';
+
+		return $gallery;
+	}
+}

includes/class-post-types.php

@@ -12,6 +12,7 @@
 use Activitypub\Collection\Followers;
 use Activitypub\Collection\Inbox;
 use Activitypub\Collection\Outbox;
+use Activitypub\Collection\Posts;
 use Activitypub\Collection\Remote_Actors;
 
 /**
@@ -25,6 +26,7 @@ public static function init() {
 		\add_action( 'init', array( self::class, 'register_remote_actors_post_type' ), 11 );
 		\add_action( 'init', array( self::class, 'register_inbox_post_type' ), 11 );
 		\add_action( 'init', array( self::class, 'register_outbox_post_type' ), 11 );
+		\add_action( 'init', array( self::class, 'register_object_post_type' ), 11 );
 		\add_action( 'init', array( self::class, 'register_extra_fields_post_types' ), 11 );
 		\add_action( 'init', array( self::class, 'register_activitypub_post_meta' ), 11 );
 
@@ -345,6 +347,65 @@ public static function register_outbox_post_type() {
 		);
 	}
 
+	/**
+	 * Register the Object post type.
+	 */
+	public static function register_object_post_type() {
+		\register_post_type(
+			Posts::POST_TYPE,
+			array(
+				'labels'              => array(
+					'name'          => \_x( 'Posts', 'post_type plural name', 'activitypub' ),
+					'singular_name' => \_x( 'Post', 'post_type single name', 'activitypub' ),
+				),
+				'capabilities'        => array(
+					'create_posts' => false,
+				),
+				'map_meta_cap'        => true,
+				'public'              => false,
+				'show_in_rest'        => true,
+				'rewrite'             => false,
+				'query_var'           => false,
+				'supports'            => array( 'title', 'editor', 'author', 'custom-fields', 'excerpt', 'comments' ),
+				'delete_with_user'    => true,
+				'can_export'          => true,
+				'exclude_from_search' => true,
+				'taxonomies'          => array( 'ap_tag', 'ap_object_type' ),
+			)
+		);
+
+		\register_taxonomy(
+			'ap_tag',
+			array( Posts::POST_TYPE ),
+			array(
+				'public'       => false,
+				'query_var'    => true,
+				'show_in_rest' => true,
+			)
+		);
+
+		\register_taxonomy(
+			'ap_object_type',
+			array( Posts::POST_TYPE ),
+			array(
+				'public'       => false,
+				'query_var'    => true,
+				'show_in_rest' => true,
+			)
+		);
+
+		\register_post_meta(
+			Posts::POST_TYPE,
+			'_activitypub_remote_actor_id',
+			array(
+				'type'              => 'integer',
+				'single'            => true,
+				'description'       => 'The local ID of the remote actor that created the object.',
+				'sanitize_callback' => 'absint',
+			)
+		);
+	}
+
 	/**
 	 * Register the Extra Fields post types.
 	 */

includes/class-sanitize.php

@@ -182,4 +182,19 @@ public static function webfinger( $value ) {
 
 		return $value;
 	}
+
+	/**
+	 * Sanitize content for ActivityPub.
+	 *
+	 * @param string $content The content to convert.
+	 *
+	 * @return string The converted content.
+	 */
+	public static function content( $content ) {
+		$content = \make_clickable( $content );
+		$content = \wpautop( $content );
+		$content = \wp_kses_post( $content );
+
+		return $content;
+	}
 }

includes/collection/class-inbox.php

@@ -20,6 +20,11 @@
  * @link https://www.w3.org/TR/activitypub/#inbox
  */
 class Inbox {
+	/**
+	 * The post type for the objects.
+	 *
+	 * @var string
+	 */
 	const POST_TYPE = 'ap_inbox';
 
 	/**

includes/collection/class-outbox.php

@@ -20,6 +20,11 @@
  * @link https://www.w3.org/TR/activitypub/#outbox
  */
 class Outbox {
+	/**
+	 * The post type for the objects.
+	 *
+	 * @var string
+	 */
 	const POST_TYPE = 'ap_outbox';
 
 	/**