Editor: Add Nonce Endpoint

This is a follow up to #47843, implementing a PHP endpoint and inline scripts 
after the editor package updates. The action was originally added in
https://github.com/WordPress/gutenberg/pull/16683.

Fixes #48076.



Built from https://develop.svn.wordpress.org/trunk@46253


git-svn-id: http://core.svn.wordpress.org/trunk@46065 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/admin-ajax.php

@@ -53,6 +53,7 @@ $core_actions_get = array(
 	'autocomplete-user',
 	'dashboard-widgets',
 	'logged-in',
+	'rest-nonce',
 );
 
 $core_actions_post = array(

wp-admin/includes/ajax-actions.php

@@ -5268,3 +5268,12 @@ function wp_ajax_health_check_get_sizes() {
 
 	wp_send_json_success( $all_sizes );
 }
+
+/**
+ * Ajax handler to renew the REST API nonce.
+ *
+ * @since 5.3.0
+ */
+function wp_ajax_rest_nonce() {
+	exit( wp_create_nonce( 'wp_rest' ) );
+}

wp-includes/script-loader.php

@@ -651,27 +651,20 @@ function wp_default_packages_inline_scripts( &$scripts ) {
 	}
 	$scripts->add_inline_script(
 		'wp-api-fetch',
-		sprintf(
-			implode(
-				"\n",
+		join(
 			array(
-					'( function() {',
-					'	var nonceMiddleware = wp.apiFetch.createNonceMiddleware( "%s" );',
-					'	wp.apiFetch.use( nonceMiddleware );',
-					'	wp.hooks.addAction(',
-					'		"heartbeat.tick",',
-					'		"core/api-fetch/create-nonce-middleware",',
-					'		function( response ) {',
-					'			if ( response[ "rest_nonce" ] ) {',
-					'				nonceMiddleware.nonce = response[ "rest_nonce" ];',
-					'			}',
-					'		}',
-					'	);',
-					'} )();',
-				)
-			),
+				sprintf(
+					'wp.apiFetch.nonceMiddleware = wp.apiFetch.createNonceMiddleware( "%s" );',
 					( wp_installing() && ! is_multisite() ) ? '' : wp_create_nonce( 'wp_rest' )
 				),
+				'wp.apiFetch.use( wp.apiFetch.nonceMiddleware );',
+				sprintf(
+					'wp.apiFetch.nonceEndpoint = "%s";',
+					admin_url( 'admin-ajax.php?action=rest-nonce' )
+				),
+			),
+			"\n"
+		),
 		'after'
 	);
 	$scripts->add_inline_script(

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.3-alpha-46252';
+$wp_version = '5.3-alpha-46253';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.