Question

I need to add persistency to an NSOperationQueue, so the user can close my application without lose any data.
I’m a big fan of core data, so I’m looking for a way to store my NSOperation subclass on core data.

Any advice?

Answer 1

I’m not sure about your question but I’ll try to give you some hints.

Yes, Core Data could be a valid approach to do it. I don’t know the reason why you need to store a NSOperation.

What I can suggest, instead, is to arrange your model to deal with syncing operations. In particular, I would add an attribute to the entities you need to sync with your sever. Call it , for example, isSync and say it’s a BOOL value.

So, when a specific data is synced with server and you have received a good response, you could just modify that attribute to assume the YES value. This means that a specific data has been synced. In other words, when an object (data) is not synced, its isSync value is NO, otherwise is YES and, if you want, you can delete it.

The next time, you can sync data that have isSync value to NO. They have not been synced yet. Other elements are already synced and you can delete them to save space on your device.

To have an understanding on how syncing can be done, I really suggest to read this stackoverflow topic How to Sync iPhone Core Data with web server, and then push to other devices?.

Furthermore, if you deal with operations, you need to cancel current operations if the user has closed the app. A really interesting discussion can be found in Queue of NSOperations and handling application exit.

Obviously there could be other solutions to achieve this, but I think it could be a simply way to achieve what you want to do.

Hope that helps.