WordPress at a glance
filter is not described

wp_using_themes filter-hook . WP 5.1.0

Filters whether the current request should use themes.

Usage

add_filter( 'wp_using_themes', 'filter_function_name_6723' );
function filter_function_name_6723( $wp_using_themes ){
	// filter...

	return $wp_using_themes;
}
$wp_using_themes(true/false)
Whether the current request should use themes.

Changelog

Since 5.1.0 Introduced.

Where the hook is called

wp_using_themes()
wp_using_themes
wp-includes/load.php 1376
return apply_filters( 'wp_using_themes', defined( 'WP_USE_THEMES' ) && WP_USE_THEMES );

Where the hook is used (in WP core)

wp-includes/load.php 766
add_filter( 'wp_using_themes', '__return_false' );