Add support for W3-Total-Cache

integration/class-w3-total-cache.php

@@ -0,0 +1,61 @@
+<?php
+/**
+ * W3 Total Cache extension for ActivityPub requests.
+ *
+ * @package activitypub
+ */
+
+namespace Activitypub\Integration;
+
+use function Activitypub\is_activitypub_request;
+
+/**
+ * W3 Total Cache extension for ActivityPub requests.
+ */
+class W3_Total_Cache {
+
+	/**
+	 * Initialize the W3 Total Cache integration.
+	 */
+	public static function init() {
+		\w3tc_add_action( 'pagecache_page_key', array( self::class, 'pagecache_page_key' ) );
+		\add_filter( 'w3tc_pgcache_rules_apache_last', array( self::class, 'w3tc_pgcache_rules_apache_last' ) );
+	}
+
+	/**
+	 * Filter: Allow adding additional rules at the end of the PGCACHE_CORE block, before the last rule.
+	 *
+	 * @since 2.7.1
+	 *
+	 * @param string $key The page key.
+	 *
+	 * @return string The modified page key.
+	 */
+	public static function pagecache_page_key( $key ) {
+		// Check if this is an ActivityPub request.
+		if ( is_activitypub_request() ) {
+			$key['key'][1] .= '_activitypub';
+		}
+
+		return $key;
+	}
+
+	/**
+	 * Modify the Apache caching rules for ActivityPub requests.
+	 *
+	 * @param array $rules The existing Apache rules.
+	 *
+	 * @return array The modified Apache rules.
+	 */
+	public static function w3tc_pgcache_rules_apache_last( $rules ) {
+		// Add check for ActivityPub Accept header (Content Negotiation).
+		$rules .= 'RewriteCond %{HTTP:Accept} (application/(ld\+json|activity\+json|json)) [NC]' . PHP_EOL;
+		$rules .= 'RewriteRule .* - [E=W3TC_ACTIVITYPUB:_activitypub]' . PHP_EOL;
+
+		// Also set the environment variable if activitypub parameter is explicitly set.
+		$rules .= 'RewriteCond %{QUERY_STRING} (?:^|&)activitypub(?:=|&|$) [NC]' . PHP_EOL;
+		$rules .= 'RewriteRule .* - [E=W3TC_ACTIVITYPUB:_activitypub]' . PHP_EOL;
+
+		return $rules;
+	}
+}

integration/load.php

@@ -182,3 +182,12 @@ function ( $post_types ) {
  * @see https://buddypress.org/
  */
 add_action( 'bp_include', array( __NAMESPACE__ . '\Buddypress', 'init' ), 0 );
+
+/**
+ * Load the W3 Total Cache integration.
+ *
+ * @see https://w3-total-cache.com/
+ */
+if ( function_exists( 'w3tc_add_action' ) ) {
+	\w3tc_add_action( 'wp_loaded', array( __NAMESPACE__ . '\W3_Total_Cache', 'init' ) );
+}