ios - Object became nil after view will appear -

following situation:

i got 2 views. on firstview m display event data, on seconde can edit these data. if switch seconde view , edit value , return firstview works should. if dont change data , return back, event objecct nil.

the funny part is: before switch second view user can decide(uiactionsheet) wich changes (name etc.). @ point m logging object , nil. on viewwillappear - seconde time view loads - object not nil.

i changed property attribute of event object (strong, nonatomic), when dont change object still exists..

i provide code m @ home, maybe have idea..

firstview

- (void)viewdidload {     [super viewdidload];     // additional setup after loading view nib.       [advthememanager customizeview:self.view];      [self initviewdata];     [self editviewstyles]; }  - (void)viewwillappear:(bool)animated{     [super viewwillappear:yes];     nslog(@"view appear!!");     nslog(@"eventname: %@", eventobject.name);     nslog(@"userid: %@", appuser.userid); // logs proves @ second load of view object not nil!!! check ->     - (void)eventoptionsheet!!     [self initviewdata]; }  - (void) initviewdata{     self.inviteduserlist.delegate = self;     self.inviteduserlist.datasource = self;      self.accepteduserlist.delegate = self;     self.accepteduserlist.datasource = self;      dccon = [[dcconnector alloc]init];       nslog(@"eventname: %@", eventobject.name);     nslog(@"userid: %@", appuser.userid);      invitedusers = [nsmutablearray arraywitharray:[eventobject.invitedusers allobjects]];     acceptedusers = [nsmutablearray arraywitharray:[eventobject.acceptedusers allobjects]];      eventdescriptionfield.text = eventobject.descrptn;      nsstring *eventimagename = [nsstring stringwithformat:@"%@_%@", eventobject.name, eventobject.date];      if ([utilitiehandler checkiffileexistswitchexstensio:eventimagename :@"png"]) {         [eventimage setbackgroundimage:[utilitiehandler loadimage:[nsstring stringwithformat:@"%@.png", eventimagename]] forstate:uicontrolstatenormal];     }      // replace titleview     cgrect headertitlesubtitleframe = cgrectmake(0, 0, 200, 44);     uiview* _headertitlesubtitleview = [[uilabel alloc] initwithframe:headertitlesubtitleframe];     _headertitlesubtitleview.backgroundcolor = [uicolor clearcolor];     _headertitlesubtitleview.autoresizessubviews = yes;      cgrect titleframe = cgrectmake(0, 2, 200, 24);     uilabel *titleview = [[uilabel alloc] initwithframe:titleframe];     titleview.backgroundcolor = [uicolor clearcolor];     titleview.textcolor = [uicolor colorwithred:0.98f green:0.96f blue:0.94f alpha:1.00f];     titleview.font = [uifont fontwithname:@"opensans-semibold" size:16];     titleview.textalignment = uitextalignmentcenter;     titleview.shadowcolor = [uicolor darkgraycolor];     titleview.shadowoffset = cgsizemake(0, -1);     titleview.text = eventobject.name;     titleview.adjustsfontsizetofitwidth = no;     [_headertitlesubtitleview addsubview:titleview];      cgrect subtitleframe = cgrectmake(0, 24, 200, 44-24);     uilabel *subtitleview = [[uilabel alloc] initwithframe:subtitleframe];     subtitleview.backgroundcolor = [uicolor clearcolor];     subtitleview.textcolor = [uicolor colorwithred:0.98f green:0.96f blue:0.94f alpha:1.00f];     subtitleview.font = [uifont fontwithname:@"opensans-semibolditalic" size:12];     subtitleview.textalignment = uitextalignmentcenter;     subtitleview.shadowcolor = [uicolor darkgraycolor];     subtitleview.shadowoffset = cgsizemake(0, -1);     subtitleview.text = [nsstring stringwithformat:@"by %@", eventobject.createdby.displayname];     subtitleview.adjustsfontsizetofitwidth = no;     [_headertitlesubtitleview addsubview:subtitleview];      self.navigationitem.titleview = _headertitlesubtitleview;       self.imagebackground.image = [[uiimage imagenamed:@"content_box_small.png"] resizableimagewithcapinsets:uiedgeinsetsmake(10, 10, 10, 10)];       self.navigationcontroller.navigationbar.layer.shadowopacity =0.0f;     self.inviteduserlist.backgroundcolor = [uicolor clearcolor];     self.accepteduserlist.backgroundcolor = [uicolor clearcolor];        // init location map     cllocationcoordinate2d coord;     coord.latitude = [eventobject.loclatitude doublevalue];     coord.longitude = [eventobject.loclongitude doublevalue];      mkcoordinatespan span = {.latitudedelta =  0.005, .longitudedelta =  0.005};     mkcoordinateregion region = {coord, span};      mkpointannotation *annotation = [[mkpointannotation alloc] init];     annotation.coordinate = coord;      [eventlocation setregion:region];     [eventlocation selectannotation:annotation animated:yes];      //add gesture map     uilongpressgesturerecognizer *longpress = [[uilongpressgesturerecognizer alloc]                                                initwithtarget:self                                                action:@selector(navigateme)];     longpress.minimumpressduration = 0;     [eventlocation addgesturerecognizer:longpress];      //add right navbar item handles invites, setting , more...     uibarbuttonitem *settingsitem = [[uibarbuttonitem alloc]initwithtitle:@"" style:uibarbuttonitemstyleplain target:self action:@selector(eventoptionsheet)];     settingsitem.image = [uiimage imagenamed:@"navigation-btn-settings"];     [settingsitem settitletextattributes:[nsdictionary dictionarywithobjectsandkeys: [uifont fontwithname:@"opensans-semibold" size:12], uitextattributefont,nil] forstate:uicontrolstatenormal];      [self.navigationitem setrightbarbuttonitem:settingsitem];  }  - (void)eventoptionsheet{     nslog(@"creator user id: %@", eventobject.createdby.userid);     nslog(@"app user id: %@", appuser.userid);  //on second view load want change more touch navbar item , leads me method. here logs null(nil). if change on seconde view works fine again!!      if ([eventobject.createdby.userid isequaltostring:appuser.userid]) {         eventcreatorsheet = [[uiactionsheet alloc] initwithtitle:eventobject.name delegate:self                                                cancelbuttontitle:@"cancel"                                           destructivebuttontitle:@"delete event"                                                otherbuttontitles: @"change location", @"edit description", @"invite more contacts", nil];         eventcreatorsheet.actionsheetstyle = uiactionsheetstyleautomatic;         [eventcreatorsheet showfromtabbar:self.tabbarcontroller.tabbar];     }else{         nsset *invitedset = eventobject.invitedusers;         nsset *acceptedset = eventobject.acceptedusers;          bool existsininvitedlist = [[invitedset valueforkeypath:@"objectid"] containsobject:appuser.objectid];         bool existsinacceptedlist = [[acceptedset valueforkeypath:@"objectid"] containsobject:appuser.objectid];           if (existsininvitedlist) {             eventuserinvitedsheet = [[uiactionsheet alloc] initwithtitle:eventobject.name delegate:self                                                        cancelbuttontitle:@"cancel"                                                   destructivebuttontitle:nil                                                        otherbuttontitles:@"join", @"decline", @"chat creator", nil];             eventuserinvitedsheet.actionsheetstyle = uiactionsheetstyleautomatic;             [eventuserinvitedsheet showfromtabbar:self.tabbarcontroller.tabbar];         }else if (existsinacceptedlist){             eventuseracceptedsheet = [[uiactionsheet alloc] initwithtitle:eventobject.name delegate:self                                                         cancelbuttontitle:@"cancel"                                                    destructivebuttontitle:nil                                                         otherbuttontitles:@"revoke invite", @"chat creator", nil];             eventuseracceptedsheet.actionsheetstyle = uiactionsheetstyleautomatic;             [eventuseracceptedsheet showfromtabbar:self.tabbarcontroller.tabbar];         }     }  }  -(void)actionsheet:(uiactionsheet *)actionsheet clickedbuttonatindex:(nsinteger)buttonindex {     lasteventsviewcontroller  *lastevents;     locateeventviewcontroller *locateevent;     eventmembersviewcontroller *invitemoremembers;     eventdescriptionviewcontroller *eventdescriptionview;     eventdto *updateeventdto;      if (actionsheet == eventcreatorsheet) {         // creator sheet         switch (buttonindex) {             case 0:                 //remove event clicked                 [dccon deleteevent:eventobject];                 lastevents = [[lasteventsviewcontroller alloc]init];                 [[self navigationcontroller]poptorootviewcontrolleranimated:yes];                 break;             case 1:                 //edit location                 locateevent = [[locateeventviewcontroller alloc]init];                 updateeventdto = [[eventdto alloc]init];                 [updateeventdto setdtowithentity:eventobject];                 locateevent.eventdto = updateeventdto;                 locateevent.editenabled = 1;                 [[self navigationcontroller]pushviewcontroller:locateevent animated:yes];                 break;             case 2:                 //edit description                 eventdescriptionview = [[eventdescriptionviewcontroller alloc]init];                 updateeventdto = [[eventdto alloc]init];                 [updateeventdto setdtowithentity:eventobject];                 eventdescriptionview.eventdto = updateeventdto;                 eventdescriptionview.editenabled = 1;                 [[self navigationcontroller]pushviewcontroller:eventdescriptionview animated:yes];                 break;             case 3:                 //invite more contacts, check if numberofinvites < 50                 break;          }     }      if (actionsheet == eventuserinvitedsheet) {         //member sheet         switch (buttonindex) {             case 0:                 //join event clicked                 nslog(@"event test: %@, appusertest: %@", eventobject.name, appuser.userid);                  [dccon addacceptedusertoevent:eventobject :appuser];                 invitedusers = [nsmutablearray arraywitharray:[eventobject.invitedusers allobjects]];                 acceptedusers = [nsmutablearray arraywitharray:[eventobject.acceptedusers allobjects]];                 [accepteduserlist reloaddata];                 [inviteduserlist reloaddata];                 break;             case 1:                 //decline event                 [dccon removeinviteduserfromevent:eventobject :appuser];                 [dccon deleteevent:eventobject];                 lastevents = [[lasteventsviewcontroller alloc]init];                 [[self navigationcontroller]pushviewcontroller:lastevents animated:yes];                 break;             case 2:                 //chat creator                 break;         }     }      if (actionsheet == eventuseracceptedsheet) {         //member sheet         switch (buttonindex) {             case 0:                 //leave event clicked                 [dccon removeaccepteduserfromevent:eventobject :appuser];                 [dccon deleteevent:eventobject];                 lastevents = [[lasteventsviewcontroller alloc]init];                 [[self navigationcontroller]pushviewcontroller:lastevents animated:yes];                 break;             case 1:                 //chat creator                 break;         }     }      if (actionsheet == changeimagesheet) {         uiimagepickercontroller *imagepickercontroller = [[uiimagepickercontroller alloc] init];         imagepickercontroller.allowsediting = yes;          switch (buttonindex) {             case 0:                 //remove user clicked                 imagepickercontroller.delegate = self;                 imagepickercontroller.sourcetype =  uiimagepickercontrollersourcetypecamera;                  [self presentmodalviewcontroller:imagepickercontroller animated:yes];                 break;             case 1:                 //show creator                 imagepickercontroller.delegate = self;                 imagepickercontroller.sourcetype =  uiimagepickercontrollersourcetypephotolibrary;                  [self presentmodalviewcontroller:imagepickercontroller animated:yes];                 break;         }     } } 

seconde view

@interface eventdescriptionviewcontroller (){     dcconnector *dccon; }  @end  @implementation eventdescriptionviewcontroller  @synthesize imagebackground, descriptiontextfield, editenabled, eventdto;  - (id)initwithnibname:(nsstring *)nibnameornil bundle:(nsbundle *)nibbundleornil {     self = [super initwithnibname:nibnameornil bundle:nibbundleornil];     if (self) {         // custom initialization     }     return self; }  - (void)viewdidload {     [super viewdidload];     // additional setup after loading view nib.      [advthememanager customizeview:self.view];      [self initviewdata];      [self styleviews]; }  - (void) initviewdata{     uilabel *labeltitle = [[uilabel alloc] initwithframe:cgrectzero];     labeltitle.backgroundcolor = [uicolor clearcolor];     labeltitle.textcolor = [uicolor colorwithred:0.98f green:0.96f blue:0.94f alpha:1.00f];     labeltitle.font = [uifont fontwithname:@"opensans-semibold" size:16];     labeltitle.text = @"event description";     [labeltitle sizetofit];     uiview *viewtitle = [[uiview alloc] initwithframe:labeltitle.bounds];     cgrect framelbl = labeltitle.bounds;     viewtitle.frame = framelbl;     [viewtitle addsubview:labeltitle];     [self.navigationitem settitleview:viewtitle];      self.view.backgroundcolor = [uicolor colorwithpatternimage:[uiimage imagenamed:@"background-tbl"]];     self.imagebackground.image = [[uiimage imagenamed:@"content_box_small.png"] resizableimagewithcapinsets:uiedgeinsetsmake(10, 10, 10, 10)];       if (editenabled == 1) {         uibarbuttonitem *neweventtoggleview = [[uibarbuttonitem alloc]initwithtitle:@"save" style:uibarbuttonitemstyleplain target:self action:@selector(updateevent)];         [neweventtoggleview settitletextattributes:[nsdictionary dictionarywithobjectsandkeys: [uifont fontwithname:@"opensans-semibold" size:12.0], uitextattributefont,nil] forstate:uicontrolstatenormal];          [self.navigationitem setrightbarbuttonitem:neweventtoggleview];          descriptiontextfield.text = eventdto.description;      }else{         uibarbuttonitem *neweventtoggleview = [[uibarbuttonitem alloc]initwithtitle:@"next" style:uibarbuttonitemstyleplain target:self action:@selector(initnexteventview)];         [neweventtoggleview settitletextattributes:[nsdictionary dictionarywithobjectsandkeys: [uifont fontwithname:@"opensans-semibold" size:12.0], uitextattributefont,nil] forstate:uicontrolstatenormal];          [self.navigationitem setrightbarbuttonitem:neweventtoggleview];      }       descriptiontextfield.font = [uifont fontwithname:@"opensans-semibold" size:14];  }  - (void)styleviews{     [self.descriptiontextfield.layer setborderwidth:2.0];     [self.descriptiontextfield.layer setbordercolor:[[uicolor colorwithred:(107/255.0) green:(96/255.0) blue:(84/255.0) alpha:1.00f] cgcolor]];      self.descriptiontextfield.layer.cornerradius = 5;     self.descriptiontextfield.clipstobounds = yes; } - (void)updateevent{     eventdto.description = self.descriptiontextfield.text;     //edit event , push members     dccon = [[dcconnector alloc]init];     [dccon updateevent:eventdto];     eventoverviewcontroller *overview = (eventoverviewcontroller*)[self.navigationcontroller.viewcontrollers objectatindex:1];     overview.eventobject = (event*)[dccon getobjectwithid:eventdto.entitysid];     overview.appuser = [dccon getappuser];     [[self navigationcontroller]poptoviewcontroller:overview animated:yes];  } 

firstview .h file

@property (strong, nonatomic) event *eventobject; @property (strong, nonatomic) user *appuser; //other properties 

second .h file

@property (strong, nonatomic) eventdto *eventdto; @property (nonatomic, readwrite) nsinteger editenabled; 

i think problem when returning second view, setting object edited value , saving it. if value not edited, object nil , saving nil object when returning first view. if case add condition checking nil in second view case , save data if not nil or edited.