is_preview() WordPress Function

function is_preview() {
	global $wp_query;

	if ( ! isset( $wp_query ) ) {
		_doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1.0' );
		return false;
	}

	return $wp_query->is_preview();
}
Uses	Description
wp-includes/l10n.php:__()	Retrieve the translation of $text.
wp-includes/class-wp-query.php:WP_Query::is_preview()	Is the query for a post or page preview?
wp-includes/functions.php:_doing_it_wrong()	Mark something as being incorrectly called.
Used By	Description
wp-includes/functions.php:wp_post_preview_js()	Outputs a small JS snippet on preview tabs/windows to remove `window.name` on unload.
wp-includes/post-template.php:_wp_link_page()	Helper function for wp_link_pages().
wp-includes/canonical.php:redirect_canonical()	Redirects incoming links to the proper URL based on the site url.