Emoji: First pass at support in Interactions

assets/css/activitypub-admin.css

@@ -248,6 +248,10 @@ input.blog-user-identifier {
 	margin-right: 8px;
 }
 
+.edit-comments-php .column-author img.emoji {
+	float: none;
+}
+
 .contextual-help-tabs-wrap dt {
 	font-weight: 600;
 }

includes/class-comment.php

@@ -33,6 +33,8 @@ public static function init() {
 		\add_action( 'update_option_activitypub_allow_likes', array( self::class, 'maybe_update_comment_counts' ), 10, 2 );
 		\add_action( 'update_option_activitypub_allow_reposts', array( self::class, 'maybe_update_comment_counts' ), 10, 2 );
 		\add_filter( 'pre_wp_update_comment_count_now', array( static::class, 'pre_wp_update_comment_count_now' ), 10, 3 );
+		\add_filter( 'get_comment_author', array( static::class, 'render_emoji' ), 10, 3 );
+		\add_filter( 'comment_author', array( static::class, 'unescape_emoji' ), 20 ); // After esc_html().
 	}
 
 	/**
@@ -815,4 +817,49 @@ public static function pre_wp_update_comment_count_now( $new_count, $old_count,
 	public static function is_comment_type_enabled( $comment_type ) {
 		return '1' === get_option( "activitypub_allow_{$comment_type}s", '1' );
 	}
+
+	/**
+	 * Render emoji in comment author name.
+	 *
+	 * Replaces emoji shortcodes with img tags on the get_comment_author filter.
+	 *
+	 * @param string           $author     The comment author name.
+	 * @param string           $comment_id The comment ID as a numeric string.
+	 * @param \WP_Comment|null $comment    The comment object.
+	 * @return string The comment author name with rendered emoji.
+	 */
+	public static function render_emoji( $author, $comment_id, $comment = null ) { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.FoundAfterLastUsed, VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+		$emoji_data = \get_comment_meta( $comment_id, 'activitypub_author_emoji', true );
+
+		if ( empty( $emoji_data ) ) {
+			return $author;
+		}
+
+		$emoji_tags = \json_decode( $emoji_data, true );
+		if ( ! is_array( $emoji_tags ) ) {
+			return $author;
+		}
+
+		// Build activity array for emoji replacement.
+		$activity = array( 'tag' => $emoji_tags );
+
+		return Emoji::replace_custom_emoji( $author, $activity );
+	}
+
+	/**
+	 * Selectively unescape emoji images in comment author.
+	 *
+	 * This runs at priority 20 after WordPress's esc_html() filter on comment_author.
+	 *
+	 * @param string $author The comment author name (already escaped by WordPress).
+	 * @return string The comment author name with emoji images unescaped.
+	 */
+	public static function unescape_emoji( $author ) {
+		// Only unescape if there are emoji images present.
+		if ( false !== strpos( $author, 'class="emoji"' ) ) {
+			$author = \html_entity_decode( $author, ENT_QUOTES | ENT_HTML5, 'UTF-8' );
+		}
+
+		return $author;
+	}
 }

includes/class-emoji.php

@@ -0,0 +1,225 @@
+<?php
+/**
+ * ActivityPub Emoji file.
+ *
+ * @package Activitypub
+ */
+
+namespace Activitypub;
+
+/**
+ * Handles custom emoji processing for ActivityPub content.
+ */
+class Emoji {
+
+	/**
+	 * Replace custom emoji shortcodes with their corresponding emoji.
+	 *
+	 * @param string $text     The text to process.
+	 * @param array  $activity The activity array containing emoji definitions.
+	 *
+	 * @return string The processed text with emoji replacements.
+	 */
+	public static function replace_custom_emoji( $text, $activity ) {
+		$emoji_data = self::extract_emoji_data( $activity );
+		if ( empty( $emoji_data ) ) {
+			return $text;
+		}
+
+		$emoji_attachments = self::get_emoji_attachments( $emoji_data );
+
+		foreach ( $emoji_data as $emoji ) {
+			$attachment_id = self::get_or_create_emoji_attachment( $emoji, $emoji_attachments );
+			$text          = self::replace_emoji_in_text( $text, $emoji, $attachment_id );
+		}
+
+		return $text;
+	}
+
+	/**
+	 * Extract emoji data from activity tags.
+	 *
+	 * @param array $activity The activity array containing emoji definitions.
+	 *
+	 * @return array {
+	 *      Array of emoji data with url and name keys.
+	 *
+	 *      @type string $url  The URL of the emoji image.
+	 *      @type string $name The shortcode name of the emoji (e.g., ":emoji:").
+	 *  }
+	 */
+	private static function extract_emoji_data( $activity ) {
+		if ( empty( $activity['tag'] ) || ! is_array( $activity['tag'] ) ) {
+			return array();
+		}
+
+		$emoji_data = array();
+
+		foreach ( $activity['tag'] as $tag ) {
+			if ( isset( $tag['type'] ) && 'Emoji' === $tag['type'] && ! empty( $tag['name'] ) && ! empty( $tag['icon']['url'] ) ) {
+				$emoji_data[] = array(
+					'url'  => $tag['icon']['url'],
+					'name' => $tag['name'],
+				);
+			}
+		}
+
+		return $emoji_data;
+	}
+
+	/**
+	 * Get existing emoji attachments for the given emoji data.
+	 *
+	 * @param array $emoji_data {
+	 *      Array of emoji data with url and name keys.
+	 *
+	 *      @type string $url  The URL of the emoji image.
+	 *      @type string $name The shortcode name of the emoji (e.g., ":emoji:").
+	 * }
+	 *
+	 * @return array {
+	 *      Array containing two lookup arrays:
+	 *
+	 *      @type array $url_to_attachment  Lookup array mapping emoji URLs to attachment IDs.
+	 *      @type array $name_to_attachment Lookup array mapping emoji names to attachment IDs.
+	 * }
+	 */
+	private static function get_emoji_attachments( $emoji_data ) {
+		// Single query for all emoji at once.
+		$meta_query = array( 'relation' => 'OR' );
+
+		foreach ( $emoji_data as $emoji ) {
+			$meta_query[] = array(
+				'key'   => 'activitypub_emoji_source_url',
+				'value' => $emoji['url'],
+			);
+			$meta_query[] = array(
+				'key'   => 'activitypub_emoji_placeholder',
+				'value' => $emoji['name'],
+			);
+		}
+
+		$existing_attachments = \get_posts(
+			array(
+				'post_type'      => 'attachment',
+				'posts_per_page' => -1,
+				'fields'         => 'ids',
+
+				// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
+				'meta_query'     => $meta_query,
+			)
+		);
+
+		// Build lookup arrays for fast access.
+		$url_to_attachment  = array();
+		$name_to_attachment = array();
+
+		foreach ( $existing_attachments as $post_id ) {
+			$source_url  = \get_post_meta( $post_id, 'activitypub_emoji_source_url', true );
+			$placeholder = \get_post_meta( $post_id, 'activitypub_emoji_placeholder', true );
+
+			if ( $source_url ) {
+				$url_to_attachment[ $source_url ] = $post_id;
+			}
+			if ( $placeholder ) {
+				$name_to_attachment[ $placeholder ] = $post_id;
+			}
+		}
+
+		return array(
+			'url_to_attachment'  => $url_to_attachment,
+			'name_to_attachment' => $name_to_attachment,
+		);
+	}
+
+	/**
+	 * Get existing emoji attachment or create a new one.
+	 *
+	 * @param array $emoji             Single emoji data with url and name.
+	 * @param array $emoji_attachments Lookup arrays from get_emoji_attachments.
+	 *
+	 * @return int Attachment ID or 0 if failed.
+	 */
+	private static function get_or_create_emoji_attachment( $emoji, $emoji_attachments ) {
+		$existing_attachment  = $emoji_attachments['url_to_attachment'][ $emoji['url'] ] ?? 0;
+		$existing_placeholder = $emoji_attachments['name_to_attachment'][ $emoji['name'] ] ?? 0;
+
+		// If we have a different image for this placeholder, or no existing image, download the new one.
+		if ( empty( $existing_attachment ) || ! empty( $existing_placeholder ) ) {
+			return self::download_emoji( $emoji['name'], $emoji['url'] );
+		}
+
+		return $existing_attachment;
+	}
+
+	/**
+	 * Download and store emoji as attachment.
+	 *
+	 * @param string $emoji_name The emoji placeholder name.
+	 * @param string $emoji_url  The emoji source URL.
+	 *
+	 * @return int Attachment ID or 0 if failed.
+	 */
+	private static function download_emoji( $emoji_name, $emoji_url ) {
+		if ( ! function_exists( '\download_url' ) ) {
+			require_once \ABSPATH . 'wp-admin/includes/file.php';
+		}
+
+		$temp_file = \download_url( $emoji_url, 10 ); // 10 second timeout for emoji downloads.
+		if ( \is_wp_error( $temp_file ) ) {
+			return 0;
+		}
+
+		$file_array = array(
+			'name'     => \wp_basename( $emoji_url ),
+			'tmp_name' => $temp_file,
+		);
+
+		if ( ! function_exists( '\media_handle_sideload' ) ) {
+			require_once \ABSPATH . 'wp-admin/includes/media.php';
+			require_once \ABSPATH . 'wp-admin/includes/image.php';
+		}
+
+		$attachment_id = \media_handle_sideload( $file_array, 0, $emoji_name );
+
+		// Clean up temp file after processing.
+		if ( \is_file( $temp_file ) ) {
+			\wp_delete_file( $temp_file );
+		}
+
+		if ( \is_wp_error( $attachment_id ) ) {
+			return 0;
+		}
+
+		\update_post_meta( $attachment_id, 'activitypub_emoji_source_url', $emoji_url );
+		\update_post_meta( $attachment_id, 'activitypub_emoji_placeholder', $emoji_name );
+
+		return $attachment_id;
+	}
+
+	/**
+	 * Replace emoji shortcode in text with image or fallback.
+	 *
+	 * @param string $text          The text to process.
+	 * @param array  $emoji         Single emoji data with url and name.
+	 * @param int    $attachment_id The attachment ID or 0 if none.
+	 *
+	 * @return string The processed text.
+	 */
+	private static function replace_emoji_in_text( $text, $emoji, $attachment_id ) {
+		$emoji_url = $emoji['url'];
+		if ( $attachment_id ) {
+			$emoji_url = \wp_get_attachment_url( $attachment_id );
+		}
+
+		return str_replace(
+			$emoji['name'],
+			sprintf(
+				'<img src="%s" alt="%s" class="emoji" />',
+				\esc_url( $emoji_url ),
+				\esc_attr( trim( $emoji['name'], ':' ) )
+			),
+			$text
+		);
+	}
+}

includes/collection/class-interactions.php

@@ -8,6 +8,7 @@
 namespace Activitypub\Collection;
 
 use Activitypub\Comment;
+use Activitypub\Emoji;
 use Activitypub\Webfinger;
 use WP_Comment_Query;
 
@@ -81,6 +82,14 @@ public static function update_comment( $activity ) {
 		$comment_data['comment_author']  = \esc_attr( $meta['name'] ?? $meta['preferredUsername'] );
 		$comment_data['comment_content'] = \addslashes( $activity['object']['content'] );
 
+		add_filter(
+			'pre_comment_content',
+			function ( $comment_content ) use ( $activity ) {
+				return Emoji::replace_custom_emoji( $comment_content, $activity['object'] );
+			},
+			20 // After wp_filter_post_kses().
+		);
+
 		return self::persist( $comment_data, self::UPDATE );
 	}
 
@@ -283,6 +292,19 @@ public static function activity_to_comment( $activity ) {
 			$comment_data['comment_meta']['source_url'] = \esc_url_raw( object_to_uri( $activity['object']['url'] ) );
 		}
 
+		// Store emoji data for display-time replacement.
+		if ( ! empty( $actor['tag'] ) ) {
+			$comment_data['comment_meta']['activitypub_author_emoji'] = \wp_json_encode( $actor['tag'] );
+		}
+
+		add_filter(
+			'pre_comment_content',
+			function ( $comment_content ) use ( $activity ) {
+				return Emoji::replace_custom_emoji( $comment_content, $activity['object'] );
+			},
+			20
+		);
+
 		return $comment_data;
 	}