How to design a synchronization mechanism when developing a GTD tool APP

How can I design a GTDAPP with synchronization functions, like Wunderlist and doit. im, any. do, TickTick. if you want to enable automatic updates when you are offline, you need a synchronization mechanism. After the user can connect to the Internet, the system automatically synchronizes data, or click the button to manually synchronize data. example... how can I design a GTD APP with synchronization functions, like Wunderlist and doit. im, any. do, TickTick.
If you want to enable automatic updates when you are offline, you need a synchronization mechanism. After the user can connect to the Internet, the system automatically synchronizes data, or click the button to manually synchronize data.
For example, when I was offline, I created five plans, each of which had another sub-plan, deleted two, and renamed several other plans. When I was able to access the Internet, I click the synchronize button to synchronize to the server database in time.
How is this synchronization mechanism designed? I did not see these teams share their development experience. I am sorry.
Please give me a good answer. It is best to consider it carefully. For more information, see "O (∩ _ ∩) O ".

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How can I design a GTD APP with synchronization functions, such as Wunderlist, doit. im, any. do, and TickTick.
If you want to enable automatic updates when you are offline, you need a synchronization mechanism. After the user can connect to the Internet, the system automatically synchronizes data, or click the button to manually synchronize data.
For example, when I was offline, I created five plans, each of which had another sub-plan, deleted two, and renamed several other plans. When I was able to access the Internet, I click the synchronize button to synchronize to the server database in time.
How is this synchronization mechanism designed? I did not see these teams share their development experience. I am sorry.
Please give me a good answer. It is best to consider it carefully. For more information, see "O (∩ _ ∩) O ".

This is the synchronous design of our project, and I am also seeking for optimal practices.
Http://segmentfault.com/q/1010000002541488

This server must maintain a version management, which is similar to code management software such as SVN. It must be updated for merge before each submission. Then submit. Differential checks and updates must be performed locally. Code management tools are more responsible for scenarios than you do, because collaboration is involved. Therefore, this mechanism is certainly applicable to your application scenarios.

I am looking for development experience, but I don't know how to solve it?

Save all local operations locally and perform them all during synchronization. This should be the simplest