src/Service/LinkTo.php
public function encode($data)
    {
        if ($this->isEmpty($data)) {
            return '{}';
        }

        $data = (array) $data + $this->defaults;
        $data = array_intersect_key($data, $this->defaults);

        return json_encode($data, JSON_UNESCAPED_SLASHES);
    }
public function encode($data)
    {
        if ($this->isEmpty($data)) {
            return '{}';
        }

        $data = (array) $data + $this->defaults;
        $data = array_intersect_key($data, $this->defaults);

        return json_encode($data, JSON_UNESCAPED_SLASHES);
    }
转换数组为字符串供保存到数据库

@param array $data
@return string