Toolbar: Move the logic for rendering the admin bar on `wp_footer` to `wp_admin_bar_render()`.

Clarify in the function documentation that it is now called on `wp_body_open` action first, with `wp_footer` as a fallback.

Follow-up to [47221].

Fixes #47053.
Built from https://develop.svn.wordpress.org/trunk@47455


git-svn-id: http://core.svn.wordpress.org/trunk@47242 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/admin-bar.php

@@ -55,8 +55,11 @@ function _wp_admin_bar_init() {
 /**
  * Renders the admin bar to the page based on the $wp_admin_bar->menu member var.
  *
- * This is called very late on the footer actions so that it will render after
- * anything else being added to the footer.
+ * This is called very early on the {@see 'wp_body_open'} action so that it will render
+ * before anything else being added to the page body.
+ *
+ * For backward compatibility with themes not using the 'wp_body_open' action,
+ * the function is also called late on {@see 'wp_footer'}.
  *
  * It includes the {@see 'admin_bar_menu'} action which should be used to hook in and
  * add new menus to the admin bar. That way you can be sure that you are adding at most
@@ -64,11 +67,19 @@ function _wp_admin_bar_init() {
  * the `$post` global, among others.
  *
  * @since 3.1.0
+ * @since 5.4.0 Called on 'wp_body_open' action first, with 'wp_footer' as a fallback.
  *
  * @global WP_Admin_Bar $wp_admin_bar
+ *
+ * @staticvar bool $rendered
  */
 function wp_admin_bar_render() {
 	global $wp_admin_bar;
+	static $rendered = false;
+
+	if ( $rendered ) {
+		return;
+	}
 
 	if ( ! is_admin_bar_showing() || ! is_object( $wp_admin_bar ) ) {
 		return;
@@ -100,6 +111,8 @@ function wp_admin_bar_render() {
 	 * @since 3.1.0
 	 */
 	do_action( 'wp_after_admin_bar_render' );
+
+	$rendered = true;
 }
 
 /**

wp-includes/default-filters.php

@@ -538,6 +538,7 @@ add_action( 'admin_init', '_wp_admin_bar_init' );
 add_action( 'before_signup_header', '_wp_admin_bar_init' );
 add_action( 'activate_header', '_wp_admin_bar_init' );
 add_action( 'wp_body_open', 'wp_admin_bar_render', 0 );
+add_action( 'wp_footer', 'wp_admin_bar_render', 1000 ); // Back-compat for themes not using `wp_body_open`.
 add_action( 'in_admin_header', 'wp_admin_bar_render', 0 );
 
 // Former admin filters that can also be hooked on the front end.

wp-includes/general-template.php

@@ -2892,14 +2892,6 @@ function wp_head() {
  * @since 1.5.1
  */
 function wp_footer() {
-	/**
-	 * Sets up the Admin Bar if the current theme does not use `wp_body_open`.
-	 *
-	 * @since 5.4.0
-	 */
-	if ( ! did_action( 'wp_body_open' ) ) {
-		add_action( 'wp_footer', 'wp_admin_bar_render', 1000 );
-	}
 	/**
 	 * Prints scripts or data before the closing body tag on the front end.
 	 *

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.5-alpha-47454';
+$wp_version = '5.5-alpha-47455';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.