re-add vary header (#683)

pfefferle · web-flow · commit 3b21061c498d · 2024-02-12T11:09:16.000+01:00
* re-add vary header fixes #580 * add Const to enable/disable `Vary` header * lets start with default "off"
diff --git a/README.md b/README.md
@@ -121,6 +121,7 @@ The plugin uses PHP Constants to enable, disable or change its default behaviour
 * `ACTIVITYPUB_DISABLE_INCOMING_INTERACTIONS` - Block incoming replies/comments/likes. Default: `false`.
 * `ACTIVITYPUB_DISABLE_OUTGOING_INTERACTIONS` - Disable outgoing replies/comments/likes. Default: `false`.
 * `ACTIVITYPUB_SHARED_INBOX_FEATURE` - Enable the shared inbox. Default: `false`.
+* `ACTIVITYPUB_SEND_VARY_HEADER` - Enable to send the `Vary: Accept` header. Default: `false`.
 
 ### Where can you manage your followers? ###
 
@@ -140,7 +141,7 @@ Project maintained on GitHub at [automattic/wordpress-activitypub](https://githu
 * Fixed: Remove old/abandoned Crons
 * Added: Various endpoints for the "Enable Mastodon Apps" plugin
 * Added: Event Objects
-* Improved: Post-Type support
+* Added: Vary-Header support behind feature flag
 
 ### 2.0.1 ###
 
diff --git a/activitypub.php b/activitypub.php
@@ -36,6 +36,7 @@
 \defined( 'ACTIVITYPUB_DISABLE_INCOMING_INTERACTIONS' ) || \define( 'ACTIVITYPUB_DISABLE_INCOMING_INTERACTIONS', false );
 \defined( 'ACTIVITYPUB_DISABLE_OUTGOING_INTERACTIONS' ) || \define( 'ACTIVITYPUB_DISABLE_OUTGOING_INTERACTIONS', false );
 \defined( 'ACTIVITYPUB_SHARED_INBOX_FEATURE' ) || \define( 'ACTIVITYPUB_SHARED_INBOX_FEATURE', false );
+\defined( 'ACTIVITYPUB_SEND_VARY_HEADER' ) || \define( 'ACTIVITYPUB_SEND_VARY_HEADER', false );
 
 \define( 'ACTIVITYPUB_PLUGIN_DIR', plugin_dir_path( __FILE__ ) );
 \define( 'ACTIVITYPUB_PLUGIN_BASENAME', plugin_basename( __FILE__ ) );
diff --git a/includes/functions.php b/includes/functions.php
@@ -312,6 +312,12 @@ function is_activitypub_request() {
 		}
 	}
 
+	// Check if header already sent.
+	if ( ! \headers_sent() && ACTIVITYPUB_SEND_VARY_HEADER ) {
+		// Send Vary header for Accept header.
+		\header( 'Vary: Accept' );
+	}
+
 	// One can trigger an ActivityPub request by adding ?activitypub to the URL.
 	// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.VariableRedeclaration
 	global $wp_query;
diff --git a/readme.txt b/readme.txt
@@ -121,6 +121,7 @@ The plugin uses PHP Constants to enable, disable or change its default behaviour
 * `ACTIVITYPUB_DISABLE_INCOMING_INTERACTIONS` - Block incoming replies/comments/likes. Default: `false`.
 * `ACTIVITYPUB_DISABLE_OUTGOING_INTERACTIONS` - Disable outgoing replies/comments/likes. Default: `false`.
 * `ACTIVITYPUB_SHARED_INBOX_FEATURE` - Enable the shared inbox. Default: `false`.
+* `ACTIVITYPUB_SEND_VARY_HEADER` - Enable to send the `Vary: Accept` header. Default: `false`.
 
 = Where can you manage your followers? =
 
@@ -140,7 +141,7 @@ Project maintained on GitHub at [automattic/wordpress-activitypub](https://githu
 * Fixed: Remove old/abandoned Crons
 * Added: Various endpoints for the "Enable Mastodon Apps" plugin
 * Added: Event Objects
-* Improved: Post-Type support
+* Added: Vary-Header support behind feature flag
 
 = 2.0.1 =
 

Original file line number	Diff line number	Diff line change
`@@ -312,6 +312,12 @@ function is_activitypub_request() {`
`312`	`312`	`}`
`313`	`313`	`}`
`314`	`314`
	`315`	`+ // Check if header already sent.`
	`316`	`+ if ( ! \headers_sent() && ACTIVITYPUB_SEND_VARY_HEADER ) {`
	`317`	`+ // Send Vary header for Accept header.`
	`318`	`+ \header( 'Vary: Accept' );`
	`319`	`+ }`
	`320`	`+`
`315`	`321`	`// One can trigger an ActivityPub request by adding ?activitypub to the URL.`
`316`	`322`	`// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.VariableRedeclaration`
`317`	`323`	`global $wp_query;`