public function selectField($content, $fieldName, $startempty = false, $keyName = 'id', $contentType = null)
    {
        $retval = $startempty ? [] : ['' => ''];

        if (empty($content)) {
            return $retval;
        }

        foreach ($content as $c) {
            if (is_string($contentType) && $contentType !== '') {
                $contentType = explode(',', $contentType);
            }

            if (is_array($contentType) && count($contentType) > 1) {
                $element = $c->contenttype['slug'] . '/' . $c->values[$keyName];
            } else {
                $element = $c->values[$keyName];
            }

            if (is_array($fieldName)) {
                $row = [];
                foreach ($fieldName as $fn) {
                    if ($fn === 'contenttype') {
                        $row[] = $c->contenttype['singular_name'];
                    } else {
                        $row[] = isset($c->values[$fn]) ? $c->values[$fn] : null;
                    }
                }
                $retval[$element] = $row;
            } elseif ($fieldName === 'contenttype') {
                $retval[$element] = $c->contenttype['singular_name'];
            } elseif (isset($c->values[$fieldName])) {
                $retval[$element] = $c->values[$fieldName];
            }
        }

        return $retval;
    }