iphone core data synchronization with ruby on rails

How do you suggest to a noob (in Obj c and ROR haha, I got some apps on both going but not very complex..) to go about getting my next project to synchronise,

I have an app in the iphone that uses coredata to store the info (using one to many relationship), working,

but I need to sync it to a ROR web app, so the user can send data from iphone to ROR and viceverza, and that if the user is offline (not connected to server,) when goes back again online, the data created or modified can be updated to or from the server,,,

I've checked the objective resource group, but to my dismay, is still a bit difficult (I have it running connected to the server but not stand alone)开发者_运维问答

what other option can I use? is there a project that is on to this?? (high hopes!!)

thank you so much!

Try RestKit, it supports integration of Rails, Core Data and Three20, It hase many other features. A nice tutorial can be found here.