public function isSelected(PhingFile $basedir, $filename, PhingFile $file)
    {
        $this->validate();

        if (count($this->parameters) > 0 && $this->dynselector instanceof ExtendFileSelector) {
            // We know that dynselector must be non-null if no error message
            $this->dynselector->setParameters($this->parameters);
        }

        return $this->dynselector->isSelected($basedir, $filename, $file);
    }