Simple Payments Block: Fix availability (#10833)

class.jetpack-gutenberg.php

@@ -60,6 +60,21 @@ public static function load_blocks() {
 			return;
 		}
 
+		if ( Jetpack_Constants::is_true( 'REST_API_REQUEST' ) ) {
+			// We defer the loading of the blocks until we have a better scope in reset requests.
+			add_filter( 'rest_request_before_callbacks', array( __CLASS__, 'defered_register_blocks' ) );
+			return;
+		}
+
+		self::register_blocks();
+	}
+
+	static function defered_register_blocks( $request ) {
+		self::register_blocks();
+		return $request;
+	}
+
+	static function register_blocks() {
 		/**
 		 * Filter the list of blocks that are available through jetpack.
 		 *
@@ -70,13 +85,16 @@ public static function load_blocks() {
 		 * @param array
 		 */
 		self::$blocks_index = apply_filters( 'jetpack_set_available_blocks', array() );
-
 		foreach ( self::$jetpack_blocks as $type => $args ) {
 			if ( 'publicize' === $type ) {
 				// publicize is not actually a block, it's a gutenberg plugin.
 				// We will handle it's registration on the client-side.
 				continue;
 			}
+			if ( isset( $args['availability']['callback'] ) ) {
+				$args['availability'] = call_user_func( $args['availability']['callback'] );
+				self::$jetpack_blocks[ $type ] = $args; // update this so that we don't have to call it again
+			}
 			if ( isset( $args['availability']['available'] ) && $args['availability']['available'] && in_array( $type, self::$blocks_index ) ) {
 				register_block_type( 'jetpack/' . $type, $args['args'] );
 			}

modules/simple-payments/simple-payments.php

@@ -58,11 +58,13 @@ public function init_hook_action() {
 
 		add_filter( 'the_content', array( $this, 'remove_auto_paragraph_from_product_description' ), 0 );
 
-		if ( $this->is_enabled_jetpack_simple_payments() ) {
-			jetpack_register_block( 'simple-payments' );
-		} else {
-			jetpack_register_block( 'simple-payments', array(), array( 'available' => false, 'unavailable_reason' => 'missing_plan' ) );
-		}
+		jetpack_register_block( 'simple-payments', array(), array( 'callback' => array( $this, 'get_block_availability' ) ) );
+	}
+
+	function get_block_availability() {
+		return $this->is_enabled_jetpack_simple_payments()
+		       ? array( 'available' => true )
+		       : array( 'available' => false, 'unavailable_reason' => 'missing_plan' );
 	}
 
 	function remove_auto_paragraph_from_product_description( $content ) {