Running into error when updating core data model object (iOS) -

i running weird error when try , update core data object (null error). first time save object (restaurant) saves perfectly. however, when try , update restaurant - running errors:

restaurantdetailviewcontroller.h :

@class restaurant;  @interface restaurantdetailviewcontroller : uitableviewcontroller <uinavigationcontrollerdelegate, uitextviewdelegate, cuisinepickerviewcontrollerdelegate>   @property (nonatomic, strong) iboutlet uitextview *reviewtextview; @property (nonatomic, strong) iboutlet uilabel *cuisinelabel; @property (nonatomic, strong) iboutlet uilabel *datelabel; @property (strong, nonatomic) iboutlet uilabel *addresslabel;  @property (nonatomic, copy) nsstring *name; @property (nonatomic, copy) nsstring *address; @property (nonatomic, assign) double longitude; @property (nonatomic, assign) double latitude;  @property (nonatomic, assign) cllocationcoordinate2d coordinate; @property (nonatomic, strong) nsmanagedobjectcontext *managedobjectcontext; @property (nonatomic, strong) restaurant *restauranttoedit;   - (ibaction)done:(id)sender; - (ibaction)cancel:(id)sender; @end 

restaurantdetailviewcontroller.m:

- (void)viewdidload {   [super viewdidload];    if (self.restauranttoedit != nil) {     self.navigationitem.title = @"edit restaurant";      self.navigationitem.rightbarbuttonitem = [[uibarbuttonitem alloc]                                               initwithbarbuttonsystemitem:uibarbuttonsystemitemdone                                               target:self                                               action:@selector(done:)];   }    date = [nsdate date];    self.navigationitem.title = name;   self.reviewtextview.text = reviewtext;   self.cuisinelabel.text = @"no cuisine selected";   self.addresslabel.text = address;   self.datelabel.text = [self formatdate:date];   - (ibaction)done:(id)sender {    restaurant *restaurant = nil;   if (self.restauranttoedit != nil) {     restaurant = self.restauranttoedit;   } else {     restaurant = [nsentitydescription insertnewobjectforentityforname:@"restaurant" inmanagedobjectcontext:self.managedobjectcontext];   }    restaurant.restaurantname = name;   restaurant.restaurantreview = reviewtext;   restaurant.cuisine = cuisinetype;   restaurant.latitude = [nsnumber numberwithdouble:self.latitude];   restaurant.longitude = [nsnumber numberwithdouble:self.longitude];   restaurant.date = date;   restaurant.address = address;    nserror *error;   if (![self.managedobjectcontext save:&error]) {     nslog(@"error %@", error);     abort();     return;   }     [self performselector:@selector(closescreen) withobject:nil afterdelay:0.6]; }  - (void)setrestauranttoedit:(restaurant *)newrestauranttoedit {   if (restauranttoedit != newrestauranttoedit) {     restauranttoedit = newrestauranttoedit;      reviewtext = restauranttoedit.restaurantreview;     cuisinetype = restauranttoedit.cuisine;     date = restauranttoedit.date;     address = restauranttoedit.address;   } } 

relevant code in mapviewcontroller.m :

- (void)prepareforsegue:(uistoryboardsegue *)segue sender:(id)sender {    if ([segue.identifier isequaltostring:@"editrestaurant"]) {        uinavigationcontroller *navigationcontroller = segue.destinationviewcontroller;       restaurantdetailviewcontroller *controller = (restaurantdetailviewcontroller *)navigationcontroller.topviewcontroller;        if (newrestaurant == yes) {         controller.name = restaurantname;         controller.address = restaurantaddress;         controller.longitude = restaurantlongitude;         controller.latitude = restaurantlatitude;         controller.managedobjectcontext = self.managedobjectcontext;       } else {         restaurant *restaurant = [restaurants objectatindex:((uibutton *)sender).tag];         controller.restauranttoedit = restaurant;       }   } }  

only thing pops in nslog (null) error. if need more code, let me know.

it appears in prepareforsegue method, aren't setting controller.managedobjectcontext property if it's update. need add

controller.managedobjectcontext = self.managedobjectcontext; 

so that's it's called whether new restaurant or update.