CoreData and UITableView: display values in cells - objective-c

Question

I'm working with Core Data and web service, I want to add my data to my table,
but I don't know how should I call them, would you please help me, since when I used this way it's not working.
Here is my method for update database in my HTTP class
- (void)updateLocalCardsDataBase:(NSArray*) cardsArray
{
//check if current user has cards in local database
NSManagedObjectContext* managedObjectContext = [(AppDelegate*) [[UIApplication sharedApplication] delegate] managedObjectContext];
for(NSDictionary *cardDic in cardsArray)
{
Card *card = [NSEntityDescription insertNewObjectForEntityForName:#"Card" inManagedObjectContext:managedObjectContext];
card.remote_id = [NSNumber numberWithInt:[[cardDic objectForKey:#"id"] intValue]];
card.stampNumber = [NSNumber numberWithInt:[[cardDic objectForKey:#"stampNumber"] intValue]];
card.createdAt = [NSDate dateWithTimeIntervalSince1970:[[cardDic objectForKey:#"createdAt"] intValue]];
[managedObjectContext lock];
NSError *error;
if (![managedObjectContext save:&error])
{
NSLog(#"Whoops, couldn't save: %#", [error localizedDescription]);
NSLog(#"Failed to save to data store: %#", [error localizedDescription]);
NSArray* detailedErrors = [[error userInfo] objectForKey:NSDetailedErrorsKey];
if(detailedErrors != nil && [detailedErrors count] > 0) {
for(NSError* detailedError in detailedErrors) {
NSLog(#" DetailedError: %#", [detailedError userInfo]);
}
}
else {
NSLog(#" %#", [error userInfo]);
}
}
[managedObjectContext unlock];
}
Here is my table:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath*)indexPath
{
// NSManagedObjectContext* managedObjectContext = [(AppDelegate*) [[UIApplication sharedApplication] delegate] managedObjectContext];
static NSString *CellIdentifier = #"CardsCell";
CardCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil){
NSArray *objects = [[NSBundle mainBundle] loadNibNamed:#"CardCell" owner:nil options:nil];
for (id currentObject in objects)
{
if([currentObject isKindOfClass:[UITableViewCell class]])
{
cell = (CardCell *) currentObject;
break;
}
}
NSDictionary *f = [_cards objectAtIndex:indexPath.row];
cell.stampId.text = [f objectForKey:#"stampNumber"];
NSLog(#"%#fdssfdfddavds",[f objectForKey:#"stampNumber"]);
cell.createdAt.text = [f objectForKey:#"createdAt"];
cell.CardId.text = [f objectForKey:#"id"];
return cell;
}
Edit:
My problem is how I can show data in a UITableView

Answer 1

Before call [tableView reloadData], you need to get a data source first. You will get back an array of your data models, not an NSDictionary. You can place the my example method (or a variation that suits you best) where ever best suits your needs, but this one will not filter or sort the models, it will only get all of them. Also, I will place the method in your view controller that stores the table view:
-(NSArray*)getMycards {
NSManagedObjectContext *context = [(AppDelegate*) [[UIApplication sharedApplication] delegate] managedObjectContext];
NSEntityDescription *entityDescription = [NSEntityDescription entityForName:#"Card" inManagedObjectContext:context];
NSFetchRequest *request = [[[NSFetchRequest alloc] init] autorelease];
NSError *error;
[request setEntity:entityDescription];
NSArray *cards = [context executeFetchRequest:request error:&error];
// now check if there is an error and handle it appropriatelty
// I usually return 'nil' but you don't have if you don't want
if ( error != nil ) {
// investigate error
}
return cards;
}
I recommend creating a property #property NSArray *cards in the view controller where you place your table, it will be easier to manage. One assumption I have made (since I have no other information about your view controller, a property named 'tableView' is declared in your view controller's header file (#property UITableView *tableView;), adjust the naming as needed.
With the above method, when you want to populate your array before loading the table's data:
// you put this block of code anywhere in the view controller that also has your table view
// likely in 'viewDidLoad' or 'viewDidAppear'
// and/or anywhere else where it makes sense to reload the table
self.cards = [self getMyCards];
if ( self.cards.count > 0 )
[self.tableview reloadData];
else {
// maybe display an error
}
Now, your cellForRowAtIndexPath should look like
-(UITableViewCell*tableView:tableView cellForRowAtIndexPath {
UITbaleViewCell *cell = ...;
// creating the type of cell seems fine to me
.
.
.
// keep in mind I don't know the exact make up of your card model
// I don't know what the data types are, so you will have to adjust as necessary
Card *card = self.cards[indexPath.row];
cell.stampId.text = [[NSString alloc] initWithFormat:#"%#",card.stamp];
cell.createdAt.text = [[NSString alloc] initWithFormat:#"%#",card.createdAt];
// you might want format the date property better, this might end being a lot more than what you want
cell.CardId.text = [[NSString alloc] initWithFormat:#"%#",card.id];
return cell;
}
Core Data is extremely powerful, I highly recommend the Core Data overview, followed by the Core Data Programming Guide.