ios - Core Data - fetching object -

i have tableviewcontroller food names in it. when click on accessorybutton: - fetches object in row, open detailviewcontroller , pass in init method, string containing name of food object fetched.

the detailviewcontroller let me edit name, , delegate ( detaildidsavetext:(nsstring *) )pass string value tableviewcontroller

the tableviewcontroller in it's delegate implementation wants save value.

if had create new object easy, create new managedobject , call nsentitydescription insertnewentityforname.

but in case need edit object exists. how can that?

how retrieve object editing ?

( know correct way pass object detailvc, i'm doing tests better learn core data, , love try way )

store reference object

@property (nonatomic) food *fooditemtoedit; 

and set property when accessory button tapped

- (void)tableview:(uitableview *)tableview accessorybuttontappedforrowwithindexpath:(nsindexpath *)indexpath {     self.fooditemtoedit = [self.fetchedresultscontroller objectatindexpath:indexpath]; } 

then in delegate method, if objecttoedit exists, create food if doesn't exist, set it's text.

- (void)detaildidsavetext:(nsstring *)text {     if (self.fooditemtoedit == nil) {         self.fooditemtoedit = [nsentitydescription insertnewobjectforentityforname:@"food" inmanagedobjectcontext:self.context];     }     self.fooditemtoedit.text = text; }