xcode - saving Json data to coredata IOS and show it in UITableView simultaneously -

i new ios xcode programming.currently working on app uses json data. app reads json data may large in size. need parse data , store core data when app runs next time can read data there saving lots of time. have tried using dispatch_async ui seems frozen while data being saved leading app crash. used asihttprequest read , parse json data works fine part have save data core data , load in uitableview simultaneously proving pain. if can me i'll grateful.

here code

nsstring *connectionstring = [nsstring stringwithformat:@"%@%@?song_id=%@", server_string, url_get_song_list, lassongid];  nslog(@"connection string is:\n%@", connectionstring); nsurl* url = [nsurl urlwithstring:connectionstring];  //the actual request asihttprequest *request = [asihttprequest requestwithurl:url];  // becoming request delegate //to callbacks requestfinished: or requestfailed: [request setdelegate:self]; nslog(@"fetching dataaaaaaaa %@",url);  // fire off request [request startasynchronous];  -(void) requestfinished: (asihttprequest *) request  {     nsstring *thejson = [request responsestring];     nslog(@"dataaaaaaaa,%@",thejson);     nsdictionary *responsedictionary = [thejson jsonvalue];      if ([[responsedictionary valueforkey:@"message"] iskindofclass:[nsarray class]])     {         [songsarray addobjectsfromarray:[responsedictionary valueforkey:@"message"]];          if (songsarray.count > 0)          {             dispatch_async (bgqueue, ^(void){                 [self savedownloadedsongs];                         });         }     } } 

savedownloadedsongs--> saves json core data after validations

1. create nsfetchedresultscontroller entity want store

   @property (nonatomic) nsfetchedresultscontroller fetchedresultscontroller; //initialize in viewdidload 

2. your view controller should nsfetchedresultscontrollerdelegate

3. implement delegate method nsfetchedresultscontroller

   - (void)controllerdidchangecontent:(nsfetchedresultscontroller *)controller {     [self.tableview reloaddata]; } 

4. implement data source method uitableview

   - (nsinteger)numberofsectionsintableview:(uitableview *)tableview {     return self.fetchedresultscontroller.sections.count; }  - (nsinteger)tableview:(uitableview *)tableview numberofrowsinsection:(nsinteger)section {     return [self.fetchedresultscontroller.sections[0] numberofobjects]; }  - (uitableviewcell *)tableview:(uitableview *)tableview cellforrowatindexpath:(nsindexpath *)indexpath {     static nsstring *cellidentifier = @"cell";     uitableviewcell *cell = [tableview dequeuereusablecellwithidentifier:cellidentifier forindexpath:indexpath];      if (cell == nil) {         cell = [[uitableviewcell alloc] initwithstyle:uitableviewcellstyledefault reuseidentifier:cellidentifier];     }      someobject *object = [self.fetchedresultscontroller objectatindexpath:indexpath];     cell.label.text = object.property     return cell; } 

5. everytime persist new object delegate triggered automatically , reloads table, includes new object.

edit:

if want save time, create new master-detail application. in masterviewcontroller you'll finde source code step 1 , smooth animations in step 3.