ios - Core data saving on child context not working -

for concurrency in coredata using parent-child moc concept parent context of nsmainqueueconcurrencytype , child context of nsprivatequeueconcurrencytype , below code

    - (nsmanagedobjectcontext *)managedobjectcontext      {         if (managedobjectcontext != nil) {           return managedobjectcontext;         }          nspersistentstorecoordinator *coordinator = [self persistentstorecoordinator];         if (coordinator != nil) {             managedobjectcontext = [[nsmanagedobjectcontext alloc] initwithconcurrencytype:nsmainqueueconcurrencytype];// done avoid crash when app auto logs out         managedobjectcontext.persistentstorecoordinator = coordinator;          }         return managedobjectcontext;     }      -(nsmanagedobjectcontext *)getprivatemoc     {         nsmanagedobjectcontext *private = [[nsmanagedobjectcontext alloc] initwithconcurrencytype:nsprivatequeueconcurrencytype];         [private setparentcontext:[self managedobjectcontext]];          return private;     }      -(void)storecustomerdata:(nsarray *)custdata      {          nsmanagedobjectcontext *currentbgcontext = [self getprivatemoc];  [currentbgcontext performblock:^{        (nsdictionary *jsonobject in custdata) {           customerentity *custentity = [nsentitydescription insertnewobjectforentityforname:@"customerentity" inmanagedobjectcontext:currentbgcontext];          custentity.fname   = [jsonobject field:@"fname"];         custentity.lname  = [jsonobject field:@"lname"];       }      nserror *error = nil;     if (![currentbgcontext save:&error]) {         nslog(@"error saving context: %@\n%@", [error localizeddescription], [error userinfo]);         //abort();     }  }]; 

}

if use parent context in method storecustomerdata works using child context getprivatemoc() doesn't.

please let me know if missing anything

i guess understood problem, please try below code

// used propegate saves persistent store (disk) without blocking ui - (nsmanagedobjectcontext *)mastermanagedobjectcontext {     if (_mastermanagedobjectcontext != nil) {         return _mastermanagedobjectcontext;     }      nspersistentstorecoordinator *coordinator = [self persistentstorecoordinator];     if (coordinator != nil) {         _mastermanagedobjectcontext = [[nsmanagedobjectcontext alloc] initwithconcurrencytype:nsprivatequeueconcurrencytype];         _mastermanagedobjectcontext.retainsregisteredobjects = yes; //to-do : need update later         [_mastermanagedobjectcontext performblockandwait:^{             [_mastermanagedobjectcontext setpersistentstorecoordinator:coordinator]; //            [_mastermanagedobjectcontext setundomanager:nil];          }];      }     return _mastermanagedobjectcontext; }  // return nsmanagedobjectcontext used in background during sync - (nsmanagedobjectcontext *)backgroundmanagedobjectcontext {     if (_backgroundmanagedobjectcontext != nil) {         return _backgroundmanagedobjectcontext;     }      nsmanagedobjectcontext *mastercontext = [self mastermanagedobjectcontext];     if (mastercontext != nil) {         _backgroundmanagedobjectcontext = [[nsmanagedobjectcontext alloc] initwithconcurrencytype:nsprivatequeueconcurrencytype];         [_backgroundmanagedobjectcontext performblockandwait:^{             [_backgroundmanagedobjectcontext setparentcontext:mastercontext];         }];     }      return _backgroundmanagedobjectcontext; }  // return nsmanagedobjectcontext used in background during sync - (nsmanagedobjectcontext *)newmanagedobjectcontext {     nsmanagedobjectcontext *newcontext = nil;     nsmanagedobjectcontext *mastercontext = [self mastermanagedobjectcontext];     if (mastercontext != nil) {         newcontext = [[nsmanagedobjectcontext alloc] initwithconcurrencytype:nsmainqueueconcurrencytype];         [newcontext performblockandwait:^{             [newcontext setparentcontext:mastercontext];         }];     }      return newcontext; }  - (void)savemastercontext {     [self.mastermanagedobjectcontext performblockandwait:^{         nserror *error = nil;         bool saved = [self.mastermanagedobjectcontext save:&error];         if (!saved) {             // real error handling             //nslog(@"could not save master context due %@", error);         }     }]; }  - (void)savebackgroundcontext {     [self.backgroundmanagedobjectcontext performblockandwait:^{         nserror *error = nil;         bool saved = [self.backgroundmanagedobjectcontext save:&error];         if (!saved) {             // real error handling             //nslog(@"could not save background context due %@", error);         }     }]; }     static dispatch_queue_t coredata_background_save_queue;  dispatch_queue_t background_save_queue() {     if (coredata_background_save_queue == null)     {         coredata_background_save_queue = dispatch_queue_create("com.magicalpanda.coredata.backgroundsaves", 0);     }     return coredata_background_save_queue; }  - (void)savedatainbackgroundwithcontext:(void(^)(nsmanagedobjectcontext *context))saveblock {  dispatch_async(dispatch_get_global_queue(dispatch_queue_priority_background, 0), ^{   [self savedataincontext:saveblock];  }); }  - (void)savedataincontext:(void(^)(nsmanagedobjectcontext *context))saveblock {  nsmanagedobjectcontext *context = [[efcoredatacontroller sharedinstance] backgroundmanagedobjectcontext];  [context setmergepolicy:nsmergebypropertyobjecttrumpmergepolicy];  [[self objectcontext] setmergepolicy:nsmergebypropertystoretrumpmergepolicy]; // [[self objectcontext] observecontext:context];      //step 3  // block(context);          //step 4  if ([context haschanges])        //step 5  {         nserror *e;   [[self objectcontext] save:&e];  //magicalrecord dump errors console save method  } }