Call numberOfSectionsInTableView after insertion a row inside the UITableView - ios

Question

what I am trying to do is inserting data from Core Data inside UITableView everything is going to be fine except one trick if there is no data inside Core Data I only display a label message that said no data is inserted yet I already made many researches about this topic and how to implemented.
I found this
iOS Programming 101: Implementing Pull-to-Refresh and Handling Empty Table which not a complete tutorial and also i search on stack for some examples i just found How can I call numberOfSectionsInTableView multiple times?
here is my full implementation of code:
- (IBAction)refresh:(id)sender {
[self getAllReservationHistory];
[sender endRefreshing];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *cellIdentifier = #"Cell";
EntryCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier forIndexPath:indexPath];
ReservationEntity *reservationEntry = [self.fetchedResultController objectAtIndexPath:indexPath];
[cell configureCellForEntry:reservationEntry];
return cell;
}
-(NSFetchRequest *) entryListFetchRequest {
NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:#"Reservations"];
[fetchRequest setFetchLimit:10];
[self.tableView reloadData];
fetchRequest.sortDescriptors = #[[NSSortDescriptor sortDescriptorWithKey:#"reservationID" ascending:NO]];
return fetchRequest;
}
// this method is used to fetch the data //
-(NSFetchedResultsController *) fetchedResultController {
if(_fetchedResultController != nil)
return _fetchedResultController;
CoreData *coreDataStack = [CoreData defaultStack];
NSFetchRequest *fechtRequest = [self entryListFetchRequest];
_fetchedResultController = [[NSFetchedResultsController alloc] initWithFetchRequest:fechtRequest managedObjectContext:coreDataStack.managedObjectContext sectionNameKeyPath:nil cacheName:nil];
_fetchedResultController.delegate = self;
return _fetchedResultController;
}
//- (CGFloat)tableView:(UITableView *)tableView
//heightForFooterInSection:(NSInteger)section {
// //differ between your sections or if you
// //have only on section return a static value
// return 50;
//}
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if([segue.identifier isEqualToString:#"details"])
{
UITableViewCell *cell = sender;
NSIndexPath *indexPath = [self.tableView indexPathForCell:cell];
UINavigationController *naviagationController = segue.destinationViewController;
DetailedHistoryViewController *detailedHisotryViewController = (DetailedHistoryViewController *) naviagationController.topViewController;
detailedHisotryViewController.entry = [self.fetchedResultController objectAtIndexPath:indexPath];
}
}
-(void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath
{
switch (type) {
case NSFetchedResultsChangeInsert:
[self.tableView insertRowsAtIndexPaths:#[newIndexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
if ([self.tableView numberOfRowsInSection:0] > 10) {
[self.tableView deleteRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
}
break;
default:
break;
}
}
/*****************************************************************************************/
- (void)viewDidLoad {
[super viewDidLoad];
[self.fetchedResultController performFetch:nil];
}
- (UIView *)tableView:(UITableView *)tableView viewForFooterInSection:(NSInteger)section
{
if (section == tableView.numberOfSections - 1) {
return [[UIView alloc] initWithFrame:CGRectMake(0, 0, 1, 1)];
}
return nil;
}
- (CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section
{
if (section == tableView.numberOfSections - 1) {
return 1;
}
return 0;
}
//
//- (UIView *)tableView:(UITableView *)tableView viewForFooterInSection:(NSInteger)section {
// if(footerView == nil) {
// footerView = [[UIView alloc] init];
// UIButton *button = [UIButton buttonWithType:UIButtonTypeContactAdd];
// button.layer.cornerRadius = (button.frame.size.width + button.frame.size.height)/ 2.0f;
// [button setBackgroundColor:[UIColor colorWithRed:234.0/255.0 green:76.0/255.0 blue:136.0/255.0 alpha:1.0f]];
// //the button should be as big as a table view cell
// [button setFrame:CGRectMake(300, 0, 50, 50)];
//
// //set title, font size and font color
//// [button setTitle:#"+" forState:UIControlStateNormal];
// [button.titleLabel setFont:[UIFont boldSystemFontOfSize:20]];
// [button setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
//
// //set action of the button
// [button addTarget:self action:#selector(AddReservation)
// forControlEvents:UIControlEventTouchUpInside];
//
// //add the button to the view
// [footerView addSubview:button];
// }
//
// //return the view for the footer
// return footerView;
//}
//-(void) AddReservation {
// NSLog(#"Bla");
//}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
CoreData *ch = [CoreData defaultStack];
NSFetchRequest *request = [[NSFetchRequest alloc] init];
[request setEntity:[NSEntityDescription entityForName:#"Reservations" inManagedObjectContext:ch.managedObjectContext]];
[request setIncludesSubentities:NO]; //Omit subentities. Default is YES (i.e. include subentities)
NSError *err;
NSUInteger count = [ch countForFetchRequest:request error:&err];
NSLog(#"%lu",(unsigned long)count);
if(count != 0)
{
return self.fetchedResultController.sections.count;
// return 10;
}
UILabel *messageLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height)];
messageLabel.text = #"No data is currently available. Please pull down to refresh.";
messageLabel.textColor = [UIColor blackColor];
messageLabel.numberOfLines = 0;
messageLabel.textAlignment = NSTextAlignmentCenter;
messageLabel.font = [UIFont fontWithName:#"Palatino-Italic" size:20];
[messageLabel sizeToFit];
self.tableView.backgroundView = messageLabel;
self.tableView.separatorStyle = UITableViewCellSeparatorStyleNone;
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
// Return the number of rows in the section.
id< NSFetchedResultsSectionInfo> sectionInfo = [self.fetchedResultController sections][section];
return [sectionInfo numberOfObjects];
// return 10;
}
Full Description:
Here is in details what I am trying to do is :
If there is no data inside the core data the UITableView display a label message " that there is no data" or whatever the message is and
After inserting the first reservation this label message should disappear and displaying the reservation data
Thanks in advance

Answer 1

In your numberOfSectionsInTableView after your if condition
if(count != 0)
{
return self.fetchedResultController.sections.count;
// return 10;
}
else {
return 1;
}
and in your numberOfRowsInTableView return 1 similarly
and in cellForRowAtIndexPath check if
id< NSFetchedResultsSectionInfo> sectionInfo = [self.fetchedResultController sections][section];
if([sectionInfo objects]>0)
{// display cell
}
else
{
UITableViewCell *cell = [tableView dequeueCellUsingResusableIdentifier:#"cell" atIndexPath:indexPath];
UILabel *label;
if(!cell)
{
cell = [[UITableviewCell alloc]initWithCellIdentifier:#"cell"];
label =[UILabel alloc]initWithFrame:CGRectMake(0,0,100,50)];
}
label.text = #"No data is currently available. Please pull down to refresh.";
}
}