_show_post_preview() │ WP 2.7.0

Filters the latest content for preview from the post autosave.

Internal function — this function is designed to be used by the kernel itself. It is not recommended to use this function in your code.

No Hooks.

Return

null. Nothing (null).

Usage

_show_post_preview();

Changelog

Since 2.7.0 Introduced.

_show_post_preview() code WP 6.6.2

wp-includes/revision.php 
function _show_post_preview() {
	if ( isset( $_GET['preview_id'] ) && isset( $_GET['preview_nonce'] ) ) {
		$id = (int) $_GET['preview_id'];

		if ( false === wp_verify_nonce( $_GET['preview_nonce'], 'post_preview_' . $id ) ) {
			wp_die( __( 'Sorry, you are not allowed to preview drafts.' ), 403 );
		}

		add_filter( 'the_preview', '_set_preview' );
	}
}