Swipe to delete row not Working

Question

I'm implementing in my PFQueryTableViewController ( Use Parse.com ) the works Swipe to Delete . When I go to perform the action of cancellation of the cell gives me this error and the app crashes.

Unigo 10/08/2013 15:40:50.683 [ 29142 : a0b ] User Online : between Unigo 10/08/2013 15:40:54.495 [ 29142 : a0b ] * Assertion failure in - [ UITableView _endCellAnimationsWithContext : ] , / SourceCache/UIKit_Sim/UIKit-2903.2/UITableView.m 1330 Unigo 10/08/2013 15:40:54.499 [ 29142 : a0b ] * Terminating app two to uncaught exception ' NSInternalInconsistencyException ' , reason : 'Invalid update : invalid number of rows in section 0 . The number of rows contained in an existing section after the update ( 5 ) must be equal to the number of rows contained in That section before the update ( 5 ) , plus or minus the number of rows inserted or deleted from That section (0 inserted , 1 deleted ) and plus or minus the number of rows moved into or out of That section (0 moved in , 0 moved out). '

Can you help me figure out where I'm wrong ?

@implementation FFEsami
@synthesize FFNewLabelEsameInAttesa,FFViewEsameInAttesaAvviso,clock,ShowPanel,ArrayMutable;

-(id)initWithCoder:(NSCoder *)FFaDecoder {
    self = [super initWithCoder:FFaDecoder];
    if (self) {
        self.parseClassName = FF_ESAMI_CLASS;
        self.pullToRefreshEnabled = YES;

    }
    return self;
}


#pragma mark - View lifecycle

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self SetGraphSectionView];
    [self queryForTable];
    self.tableView.allowsSelectionDuringEditing = YES;
    self.tableView.allowsMultipleSelectionDuringEditing = YES;

    // Uncomment the following line to preserve selection between presentations.
    // self.clearsSelectionOnViewWillAppear = NO;

    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
     self.navigationItem.leftBarButtonItem = self.editButtonItem;
    [self.navigationItem.leftBarButtonItem setTintColor:[UIColor whiteColor]];
}


- (void)viewDidUnload
{
    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}








- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];

    [self loadObjects];

}



#pragma mark - Parse

- (void)objectsDidLoad:(NSError *)error {
    [super objectsDidLoad:error];

    // This method is called every time objects are loaded from Parse via the PFQuery
}

- (void)objectsWillLoad {
    [super objectsWillLoad];

    // This method is called before a PFQuery is fired to get more objects
}

- (PFQuery *)queryForTable {
    PFQuery *FFQueryPerTableView = [PFQuery queryWithClassName:FF_ESAMI_CLASS  ];
    [FFQueryPerTableView whereKey: FF_ESAMI_USER equalTo: [PFUser currentUser]];
    [FFQueryPerTableView orderByDescending:FF_ESAMI_DATA_STRING];

    if ([self.objects count] == 0) {
    }
    return FFQueryPerTableView;
}

-(void)SetGraphSectionView {
    FFViewEsameInAttesaAvviso =[[UIView alloc]initWithFrame:CGRectMake(0, 0, 320, 50)] ;
    FFNewLabelEsameInAttesa = [[UILabel alloc]initWithFrame:CGRectMake(60, -1, 200, 50)];
    FFNewLabelEsameInAttesa.numberOfLines = 2;
    FFNewLabelEsameInAttesa.textAlignment = NSTextAlignmentLeft;
    FFNewLabelEsameInAttesa.textAlignment = NSTextAlignmentLeft;
    FFNewLabelEsameInAttesa.lineBreakMode = NSLineBreakByTruncatingTail;
    clock = [[UIImageView alloc] initWithFrame:CGRectMake(17, 11, 25, 25)];
  //  ShowPanel = [[UIImageView alloc] initWithFrame:CGRectMake(280, 27, 20, 20)];

}
- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section {
        return 50.0;
}
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {


if(section==0){

PFQuery *query = [PFQuery queryWithClassName:FF_ESAMI_CLASS];
[query whereKey:FF_ESAMI_USER equalTo:[PFUser currentUser]];
[query whereKey:FF_ESAMI_STATUS equalTo:[NSNumber numberWithBool:YES]];
[query orderByAscending:FF_ESAMI_DATA_STRING];
[query getFirstObjectInBackgroundWithBlock:^(PFObject *object, NSError *error) {

    if (!object) {
        NSString *titolo = [NSString stringWithFormat:@"Nessun esame imminente"];
        FFNewLabelEsameInAttesa.text = titolo;
        FFNewLabelEsameInAttesa.font = [UIFont fontWithName:@"HelveticaNeue" size:13];
        FFNewLabelEsameInAttesa.textColor = [UIColor grayColor];
        FFNewLabelEsameInAttesa.numberOfLines = 2;

        FFViewEsameInAttesaAvviso.backgroundColor = [UIColor clearColor];
        clock.image= [UIImage imageNamed:@"FFIMG_InAttesa"];

    } else {
        NSString *titolo = [NSString stringWithFormat:@"%@", [object objectForKey:FF_ESAMI_TITOLO]];
        FFNewLabelEsameInAttesa.text = titolo;
        FFNewLabelEsameInAttesa.font = [UIFont fontWithName:@"HelveticaNeue" size:13];
        FFNewLabelEsameInAttesa.textColor = [UIColor whiteColor];


        FFViewEsameInAttesaAvviso.backgroundColor = [UIColor colorWithRed:(203/255.0) green:(162/255.0) blue:(86/255.0) alpha:(0.90)];
        clock.image= [UIImage imageNamed:@"FFIMG_InAttesaBianco"]; }
}];
ShowPanel.image= [UIImage imageNamed:@"FFDownView"];
[FFViewEsameInAttesaAvviso addSubview:FFNewLabelEsameInAttesa];
[FFViewEsameInAttesaAvviso addSubview:clock];
    [FFViewEsameInAttesaAvviso addSubview:ShowPanel];
}

return FFViewEsameInAttesaAvviso;

}

-(NSInteger) numberOfSectionsInTableView:(UITableView *)tableView    {
    return 1;
}

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

    return 0;
}

- (FFCustomListaEsamiCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath object:(PFObject *)object {

    FFCustomListaEsamiCell  *cell = (FFCustomListaEsamiCell * )[self.tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];

    if (!cell) {
        cell = [[FFCustomListaEsamiCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"Cell"];
    }

    NSString *text = [object objectForKey:FF_ESAMI_TITOLO];
    cell.FFTitoloEsameLabel.numberOfLines = 2;
    cell.FFTitoloEsameLabel.text = text;


    NSDateFormatter *FFDataFormattata = [[NSDateFormatter alloc] init];
    [FFDataFormattata setDateFormat:FF_DATE_FORMATTER];
    cell.FFDataEsameLabel.text = [NSString stringWithFormat: @"%@",[FFDataFormattata stringFromDate:[object objectForKey:FF_ESAMI_DATA_STRING]]];


    PFObject *rowObject = [self.objects objectAtIndex:indexPath.row];

    if([[rowObject objectForKey:FF_ESAMI_STATUS] boolValue])
    {
        //DATO CONVALIDATO
        cell.last.image = [UIImage imageNamed:@"FFIMG_InAttesa"];


        /*UIImage *btn = [UIImage imageNamed:@"FF_ChechOk"];
        [cell.FFInserisciConvalida setImage:btn forState:UIControlStateNormal];
        [cell.FFInserisciConvalida addTarget:self
                                      action:@selector(FFConvalidaDato)
                            forControlEvents:UIControlEventTouchUpInside];
        [cell.FFAltreAzioni addTarget:self
                               action:@selector(ActionSheetForStateInAttesa)
                     forControlEvents:UIControlEventTouchUpInside];*/





    } else {

        //DATO NON CONVALIDATO
        //UIImage *btn = [UIImage imageNamed:@"FFIMG_ClockTAG"];
       /* [cell.FFInserisciConvalida setImage:btn forState:UIControlStateNormal];
        [cell.FFInserisciConvalida addTarget:self
                                      action:@selector(FFMettiInAttesa)
                            forControlEvents:UIControlEventTouchUpInside];
        [cell.FFAltreAzioni addTarget:self
                               action:@selector(ActionSheetForStateConvalidato)
                     forControlEvents:UIControlEventTouchUpInside];*/


    }


    return cell;
}



/*
 // Override if you need to change the ordering of objects in the table.
 - (PFObject *)objectAtIndex:(NSIndexPath *)indexPath {
 return [objects objectAtIndex:indexPath.row];
 }
 */

/*
 // Override to customize the look of the cell that allows the user to load the next page of objects.
 // The default implementation is a UITableViewCellStyleDefault cell with simple labels.
 - (UITableViewCell *)tableView:(UITableView *)tableView cellForNextPageAtIndexPath:(NSIndexPath *)indexPath {
 static NSString *CellIdentifier = @"NextPage";

 UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

 if (cell == nil) {
 cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
 }

 cell.selectionStyle = UITableViewCellSelectionStyleNone;
 cell.textLabel.text = @"Load more...";

 return cell;
 }
 */

#pragma mark - Table view data source


 // Override to support conditional editing of the table view.
 - (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
 {
 // Return NO if you do not want the specified item to be editable.
 return YES;
 }




 // Override to support editing the table view.
 - (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
 {
 if (editingStyle == UITableViewCellEditingStyleDelete) {


     PFObject *object = [self.objects objectAtIndex:indexPath.row];
     [object deleteInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {

         [self loadObjects];
     }];[tableView reloadRowsAtIndexPaths:[tableView indexPathsForVisibleRows] withRowAnimation:UITableViewRowAnimationFade];
    // [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];





 }
 else if (editingStyle == UITableViewCellEditingStyleInsert) {
 // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
     [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];

 }
 }



 // Override to support rearranging the table view.
 - (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath
 {
 }



 // Override to support conditional rearranging of the table view.
 - (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
 {
 // Return NO if you do not want the item to be re-orderable.
 return YES;
 }



#pragma mark - Table view delegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [super tableView:tableView didSelectRowAtIndexPath:indexPath];
}


@end

Answer 1

You have this code:

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

    return 0;
}

which is telling the table to have 0 cells in it after the update when the table is expecting 4. If you are using static cells in the storyboard then you should not implement the numberOfRowsInSection function.

If you remove that code then you should have no problems.

EDIT: Or if you do want the numberOfRowsInSection function then you need to hook up a datasource to the tableview. This would allow you to return the count of the datasource. Then, when you delete a row you would remove the corresponding object in your datasource so that the count is 1 less than it previously was.