swift - Master-Detail View Controller and CoreData -

as new swift, trying work master view controller read blog using json , store in core data. except don't understand how data gets deleted core data upon right swipe , delete. sorry ask such question , embarrassing. know sure following code deletes cant find implementation nor understand how knows entity delete data from.

 func controller(controller: nsfetchedresultscontroller, didchangeobject anobject: anyobject, atindexpath indexpath: nsindexpath?, forchangetype type: nsfetchedresultschangetype, newindexpath: nsindexpath?) {         switch type {             case .insert:                 tableview.insertrowsatindexpaths([newindexpath!], withrowanimation: .fade)             case .delete:                 *tableview.deleterowsatindexpaths([indexpath!], withrowanimation: .fade)*             case .update:                 self.configurecell(tableview.cellforrowatindexpath(indexpath!)!, atindexpath: indexpath!)             case .move:                 tableview.deleterowsatindexpaths([indexpath!], withrowanimation: .fade)                 tableview.insertrowsatindexpaths([newindexpath!], withrowanimation: .fade)             default:                 return         }     } 

please me understand how work. in advance help.

there's nothing in code deletes core data. code calls methods on uitableview. tells table view delete row screen has no effect on core data.

you delete data core data using nsmanagedobjectcontext' deleteobject: method.