_show_post_preview() WordPress Function

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' );
	}
}
Uses	Description
wp-includes/l10n.php:__()	Retrieve the translation of $text.
wp-includes/pluggable.php:wp_verify_nonce()	Verifies that a correct security nonce was used with time limit.
wp-includes/functions.php:wp_die()	Kills WordPress execution and displays HTML page with an error message.
wp-includes/plugin.php:add_filter()	Adds a callback function to a filter hook.