Save data for coredata

[badalpub1991]

I am working on rss feed based project. I am saving data which entered by user in coredata. is it possible to it also save in lockbox like [Name , websitename , feedurl] and when user uninstall app and install again then data will be copies from lockbox to coredata ?

Here is my method for save coredata .

          - (void)feedParserDidFinish:(MWFeedParser *)parser {
                 NSFetchRequest *fetchrequestforside=[NSFetchRequest      fetchRequestWithEntityName:@"Sidetablename"]; //Sidetablename is entity
                 fetchrequestforside.predicate=[NSPredicate predicateWithFormat:@"feedurl = %@", self.Feedlink];
              NSManagedObjectContext *context = [self managedObjectContext];
             if ([[context executeFetchRequest:fetchrequestforside error:NULL] count] == 0) {
                // Create a new managed object

                NSError *error = nil;

                NSPredicate *predicate=[NSPredicate predicateWithFormat:@"feedurl contains %@",check ]; //check is urlstring
                [fetchrequestforside setPredicate:predicate];
                NSMutableArray *checkp = [[context executeFetchRequest:fetchrequestforside error:&error]mutableCopy];

                if (checkp.count<=0) //if coredata will find url then notstore in coredata else storeprocedure
      {

                NSManagedObject *newDevice1 = [NSEntityDescription insertNewObjectForEntityForName:@"Sidetablename" inManagedObjectContext:context];

                if (self.Name)
                {
                    [newDevice1 setValue:self.Name forKey:@"name"];

                }
                if (self.WebsiteName)
                {
                    [newDevice1 setValue:self.WebsiteName forKey:@"websitename"];

                }

                if (self.Feedlink)
                {
                    [newDevice1 setValue:self.Feedlink forKey:@"feedurl"];

                }

                NSError *error = nil;
                if (![context save:&error]) {
                        NSLog(@"Can't Save! %@ %@", error, [error localizedDescription]); // Getting error here through nslog //CoreData: error: (1555) UNIQUE constraint failed: ZSIDETABLENAME.Z_PK

                    }

[granoff]

You can save (nearly) anything you like into the keychain using Lockbox, but you'll have to write your own code to call the Lockbox methods to do so.

You may instead want to combine iCloud with your CoreData store. After a bit of setup, and without any other specific changes to save the data in general, the data you want to persist across app deletion remains in iCloud. Then you need only detect that you can restore it from iCloud, and viola!

The keychain isn't really the place to accomplish this, but you can certainly use it for that purpose if you must.

[badalpub1991]

Thank you sire for your replay. I am fetching data from lockbox to store it in coredata. but i am not able to set it as object for key. because it will not find any key. How can i achive this ? I ahve saved it as nsarray. Here is Method :

              NSFetchRequest *fetchrequestforside=[NSFetchRequest fetchRequestWithEntityName:@"demo"];
           NSManagedObjectContext *context = [self managedObjectContext];
           NSManagedObject *newDevice1 = [NSEntityDescription insertNewObjectForEntityForName:@"demo" inManagedObjectContext:context];

              NSArray *fetchdata = [Lockbox arrayForKey:@"fetch"]; // 

                for (int i =0;i<[fetchdata count];i++){
              NSString *Name  =[[fetchdata objectAtIndex:i] objectForKey:@"name"];
              NSString *Websitename  =[[fetchdata objectAtIndex:i] objectForKey:@"websitename"];
              NSString *Feedlink  =[[fetchdata objectAtIndex:i] objectForKey:@"feedurl"];

            NSLog(@"value:%@,%@,%@",Name,Websitename,Feedlink);
               [newDevice1 setValue:Name  forKey:@"name"];

            [newDevice1 setValue:Websitename  forKey:@"websitename"];
           [newDevice1 setValue:Feedlink forKey:@"feedurl"];
              NSLog(@"value:%@,%@,%@",Name,Websitename,Feedlink);

           // Save the context.
            NSError *error = nil;
         if (![context save:&error]) {

              NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
            abort();
      }
}

I am getting data in this fom in lockbox :

<__NSArrayI 0x7fab3be54710>( { feedurl = "http://www.refernews.com/feed"; name = "Refer News"; websitename = "www.refernews.com"; }, { feedurl = "http://www.cnet.com/rss/news/"; name = "CNET - Technology "; websitename = "www.cnet.com"; }, { feedurl = "http://www.huffingtonpost.in/feeds/verticals/india/index.xml"; name = Huffingtonpost; websitename = "www.huffingtonpost.in"; }, { feedurl = "https://in.news.yahoo.com/rss/europe"; name = "Yahoo World - Europe"; websitename = "www.yahoo.com"; } )

[granoff]

I don't think the issue here is with Lockbox as much as it may be with your CoreData code. What does the class interface and implementation look like for your demo entity? The data coming out of Lockbox looks reasonable.

[badalpub1991]

yes. data comes properly from lockbox. But i am not able to fetch it in string with "objectforkey" . I have tried several method,s but after coming from lockbox it will not find "objectforkey". Moreover , I have tried it with setting simple dictionary with single key but still when debugger reached at "objectforkey" I am getting this type of error .

[granoff]

Hmm... I just created some unit tests locally to see what's happening here, and there does seem to be an issue, undoubtedly related to saving an array of dictionaries. I'll look into it.

[granoff]

The crux of the issue is that nesting complex types is a bad idea at the moment. You'd be better off persisting your array of dictionaries to a plist on disk or in iCloud if you need persistence across app deletes. The solution for this is non-trivial. I'll have to give it some thought before I dive into it.