Determines whether a clause is first-order.

A "first-order" clause is one that contains any of the first-order clause keys (‘terms’, ‘taxonomy’, ‘include_children’, ‘field’, ‘operator’). An empty clause also counts as a first-order clause, for backward compatibility. Any clause that doesn’t meet this is determined, by process of elimination, to be a higher-order query.

$query array Required

Tax query arguments.

bool Whether the query clause is a first-order clause.

File: wp-includes/class-wp-tax-query.php. View all references

protected static function is_first_order_clause( $query ) {
	return is_array( $query ) && ( empty( $query ) || array_key_exists( 'terms', $query ) || array_key_exists( 'taxonomy', $query ) || array_key_exists( 'include_children', $query ) || array_key_exists( 'field', $query ) || array_key_exists( 'operator', $query ) );
}