LdapTools\Query\OperatorCollection::getLdapFilter PHP Method

    protected function getLdapFilter($alias)
    {
        $filters = [];
        if (!is_null($alias) && !array_key_exists($alias, $this->aliases)) {
            throw new InvalidArgumentException(sprintf('Alias "%s" is not valid. Valid aliases are: %s', $alias, empty($this->aliases) ? '(none defined)' : implode(', ', array_keys($this->aliases))));
        }
        if (!is_null($alias)) {
            $filters[] = $this->aliases[$alias]->getFilter()->toLdapFilter();
        }
        foreach ($this->toArray() as $operator) {
            $filters[] = $operator->toLdapFilter($alias);
        }
        $filter = implode('', $filters);
        if (1 < count($filters)) {
            $filter = bAnd::SEPARATOR_START . bAnd::SYMBOL . $filter . bAnd::SEPARATOR_END;
        }
        return $filter;
    }