Title: WP_REST_Revisions_Controller::restore_post_data
Published: August 20, 2026

---

# WP_REST_Revisions_Controller::restore_post_data( WP_Post|null $previous_post )

## In this article

 * [Description](https://developer.wordpress.org/reference/classes/wp_rest_revisions_controller/restore_post_data/?output_format=md#description)
 * [Parameters](https://developer.wordpress.org/reference/classes/wp_rest_revisions_controller/restore_post_data/?output_format=md#parameters)
 * [Source](https://developer.wordpress.org/reference/classes/wp_rest_revisions_controller/restore_post_data/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/classes/wp_rest_revisions_controller/restore_post_data/?output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/classes/wp_rest_revisions_controller/restore_post_data/?output_format=md#changelog)

[ Back to top](https://developer.wordpress.org/reference/classes/wp_rest_revisions_controller/restore_post_data/?output_format=md#wp--skip-link--target)

This function’s access is marked private. This means it is not intended for use 
by plugin or theme developers, only by core. It is listed here for completeness.

Restores the global post to its previous value after preparing a revision.

## 󠀁[Description](https://developer.wordpress.org/reference/classes/wp_rest_revisions_controller/restore_post_data/?output_format=md#description)󠁿

Preparing a revision overwrites the global post and post data via [setup_postdata()](https://developer.wordpress.org/reference/functions/setup_postdata/).
This restores the global post that was in place beforehand so the change does not
leak into the rest of the request.

Only the global post is guaranteed to be restored. When there was no previous global
post and the main query has no post either, which is the usual state during a REST
request, [wp_reset_postdata()](https://developer.wordpress.org/reference/functions/wp_reset_postdata/)
has nothing to restore from, so the remaining globals set by [setup_postdata()](https://developer.wordpress.org/reference/functions/setup_postdata/)(
such as $id, $authordata and $pages) are left describing the revision. Clearing 
those would mean unsetting each one by hand, which is beyond what is needed to keep
the global post from leaking.

## 󠀁[Parameters](https://developer.wordpress.org/reference/classes/wp_rest_revisions_controller/restore_post_data/?output_format=md#parameters)󠁿

 `$previous_post`[WP_Post](https://developer.wordpress.org/reference/classes/wp_post/)
|nullrequired

The global post to restore, or null if there was none.

## 󠀁[Source](https://developer.wordpress.org/reference/classes/wp_rest_revisions_controller/restore_post_data/?output_format=md#source)󠁿

    ```php
    private function restore_post_data( ?WP_Post $previous_post ): void {
    	if ( $previous_post ) {
    		$GLOBALS['post'] = $previous_post;
    		setup_postdata( $previous_post );
    		return;
    	}

    	/*
    	 * There was no global post to restore, so clear the revision's post data.
    	 * This runs before clearing the global post because wp_reset_postdata()
    	 * repopulates it from the main query whenever that query has a post. Note
    	 * that it is a no-op when the main query has no post, in which case only
    	 * the global post below is cleared.
    	 */
    	wp_reset_postdata();

    	/*
    	 * Assigned rather than unset so that any `global $post` binding made before
    	 * this request keeps pointing at the global. Unsetting removes the entry from
    	 * the symbol table, which detaches those bindings, and a later write through
    	 * one of them would no longer be visible to get_post().
    	 */
    	$GLOBALS['post'] = null;
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/7.1/src/wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php#L765)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php#L765-L788)

## 󠀁[Related](https://developer.wordpress.org/reference/classes/wp_rest_revisions_controller/restore_post_data/?output_format=md#related)󠁿

| Uses | Description | 
| [setup_postdata()](https://developer.wordpress.org/reference/functions/setup_postdata/)`wp-includes/query.php` |

Set up global post data.

  | 
| [wp_reset_postdata()](https://developer.wordpress.org/reference/functions/wp_reset_postdata/)`wp-includes/query.php` |

After looping through a separate query, this function restores the $post global to the current post in the main query.

  |

| Used by | Description | 
| [WP_REST_Revisions_Controller::prepare_item_for_response()](https://developer.wordpress.org/reference/classes/wp_rest_revisions_controller/prepare_item_for_response/)`wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php` |

Prepares the revision for the REST response.

  |

## 󠀁[Changelog](https://developer.wordpress.org/reference/classes/wp_rest_revisions_controller/restore_post_data/?output_format=md#changelog)󠁿

| Version | Description | 
| [7.1.0](https://developer.wordpress.org/reference/since/7.1.0/) | Introduced. |

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