private function getConfValue(
        $fieldName,
        $sheet = 'sDEF',
        $isFileName = false,
        $ignoreFlexform = false
    ) {
        $flexformsValue = '';
        if (!$ignoreFlexform) {
            $flexformsValue = $this->pi_getFFvalue(
                $this->cObj->data['pi_flexform'],
                $fieldName,
                $sheet
            );
        }

        if ($isFileName && $flexformsValue !== null && $flexformsValue !== '') {
            $flexformsValue = $this->addPathToFileName($flexformsValue);
        }
        $confValue = isset($this->conf[$fieldName])
            ? $this->conf[$fieldName] : '';

        return $flexformsValue ?: $confValue;
    }