ios - managed object value is randomly null (Sample project included) -

after saving data (10 records) entity, processing fetch request data again:

//saving data - (void)parser:(nsxmlparser *)parser didendelement:(nsstring *)elementname namespaceuri:(nsstring *)namespaceuri qualifiedname:(nsstring *)qname{      //save coredata           song = [nsentitydescription insertnewobjectforentityforname:@"song"                                              inmanagedobjectcontext:context];         [song setvalue:title forkey:@"title"];          [song setvalue:songlink forkey:@"songweblink"];         nslog(@"song link : %@",songlink);//never null           [song setvalue:albumlink forkey:@"albumimagelink"];          nserror *error = nil;         if (![context save:&error]) {             nslog(@"whoops, couldn't save: %@", [error localizeddescription]);         }else{              nslog(@"record saved correctly");         } } 

saving above working fine , debugged data before being saved context ensure none of attributes null.

the problem songweblink attribute, gets null when try ot below:

- (void)parserdidenddocument:(nsxmlparser *)parser{      nsentitydescription *songentity=[nsentitydescription entityforname:@"song" inmanagedobjectcontext:context];     nsfetchrequest *fetch=[[nsfetchrequest alloc] init];     [fetch setentity:songentity];     nserror *fetcherror;     nsarray *fetchedsongs=[context executefetchrequest:fetch error:&fetcherror];      nsmutablearray *songs = [[nsmutablearray alloc] init];      (nsmanagedobject *songobject in fetchedsongs) {     //here issue: loop go through 10 iterations, songweblink randomly null, it's fourth iteration, 8th, 5th.         nslog(@"song web link: %@",[songobject valueforkey:@"songweblink"]);//albumimagelink , title attributes fine     } } 

the issue when nslog songweblink, gets null, once 4th iteration, 6th, 2nd etc. it's randomly assigning null attribute when fetching. when saving data, make sure there no null value songweblink. bet on else cause of issue.

any thoughts?

edit

here how moc initialized:

appdelegate.m:

- (nsmanagedobjectcontext *)managedobjectcontext {     if (_managedobjectcontext != nil) {         return _managedobjectcontext;     }      nspersistentstorecoordinator *coordinator = [self persistentstorecoordinator];     if (coordinator != nil) {         _managedobjectcontext = [[nsmanagedobjectcontext alloc] init];//i tried initwithconcurrencytype:nsmainqueueconcurrencytype         [_managedobjectcontext setpersistentstorecoordinator:coordinator];     }     return _managedobjectcontext; } 

getting moc object use in different class :

appdelegate *appdelegate = (appdelegate*)[[uiapplication sharedapplication]delegate]; context = [appdelegate managedobjectcontext]; 

sample project: if think need on app project, made simplified version on reproduced bug, can download here.

give try:

include in fetch request

[fetch setincludespropertyvalues:yes]; 

iterate through returned objects this:

for (song *songobject in fetchedsongs) {     //here issue: loop go through 10 iterations, songweblink randomly null, it's fourth iteration, 8th, 5th.     nslog(@"song web link: %@",songobject.songweblink);//albumimagelink , title attributes fine } 

i'm not 100% sure fix in finding problem if doesn't.