使用PHP / MySQL客户端实现从联机到脱机的无缝过渡?

I have PHP / MySQL front-end that uses some very large forms to collect data. I have the data saving to the database at regular intervals using a JSON post in the background. Occasionally, the user loses connectivity, but continues working. That data is then lost, causing frustration, etc...I have PHP / MySQL front-end that uses some ver