public function outputType()
    {
        if ($this->outputType === null) {
            if ($this->inputType === false && $this->displayType === false) {
                throw new LogicException('Form property widget requires an "input_type" or a "display_type"');
            }

            $type = null;

            if ($this->inputType === false || is_string($this->displayType)) {
                $type = static::PROPERTY_DISPLAY;
            }

            if ($this->displayType === false || is_string($this->inputType)) {
                $type = static::PROPERTY_CONTROL;
            }

            $this->outputType = $type;
        }

        return $this->outputType;
    }