Question

In cellForRowAtIndexPath: method I have implemented gesture recognizer for long press,

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

if (tableView == favouritesTable) {
    cellValue = [licensePlateArray objectAtIndex:indexPath.row];
} else { // handle search results table view
    cellValue = [filteredListItems objectAtIndex:indexPath.row];
}

static NSString *CellIdentifier = @"vlCell";

VehicleListCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

if (cell == nil) {

    NSLog(@"Cell Created");

    NSArray *nibObjects = [[NSBundle mainBundle] loadNibNamed:@"VehicleListCell" owner:nil options:nil];

    for (id currentObject in nibObjects) {
        if ([currentObject isKindOfClass:[VehicleListCell class]]) {
            cell = (VehicleListCell *)currentObject;
        }
    }

}

UILongPressGestureRecognizer *pressRecongnizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(tableCellPressed:)];

toDeleteObject = [results objectAtIndex:indexPath.row];
pressRecongnizer.view.tag = indexPath.row;

pressRecongnizer.minimumPressDuration = 0.5f;
[cell addGestureRecognizer:pressRecongnizer];
[pressRecongnizer release];

cell.textLabel.font = [UIFont systemFontOfSize:10];

Favouritesdata *favdata = [results objectAtIndex:indexPath.row];

[[cell ignition] setImage:[UIImage imageNamed:@"ignition.png"]];
[[cell direction] setImage:[UIImage imageNamed:@"south.png"]];

cell.licPlate.text = [favdata licenseplate];

NSLog(@"cellvalue for cellforRow: %@", cell.licPlate.text);

return cell;}

And in tableCellPressed

- (void)tableCellPressed:(UILongPressGestureRecognizer *)recognizer{
if (recognizer.state != UIGestureRecognizerStateBegan) {
    return;
}

VehicleListCell* cell = (VehicleListCell *)[recognizer view];

cellValueForLongPress = cell.licPlate.text;

NSLog(@"cell value: %@", cellValueForLongPress);

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil message:nil delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles: nil] ;

alert.tag = recognizer.view.tag;

[alert addButtonWithTitle:@"Remove from Favourites"];
[alert addButtonWithTitle:@"Show on Map"];

[alert show];}

And in alertView:

-(void)alertView:(UIAlertView *)alert clickedButtonAtIndex:(NSInteger)buttonIndex {
NSString *title = [alert buttonTitleAtIndex:buttonIndex];

if([title isEqualToString:@"Remove from Favourites"])
{
    NSLog(@"cellValueForLongPress: %@", cellValueForLongPress);

    [results removeObjectAtIndex:alert.tag];

    [context deleteObject:toDeleteObject];

    NSLog(@"alert.tag:::: %d", alert.tag);   

}
else if([title isEqualToString:@"Show on Map"])
{
    NSLog(@"Go to MapView");

    Maps *detailViewFromLabel = [Maps alloc];

    [self.view addSubview:detailViewFromLabel.view];

}

NSError *error;

if (![context save:&error]) {
    NSLog(@"Error Occured");
}

[favouritesTable reloadData];}

Through this code entry from the core data gets deleted but the issue is that it only deletes the entry at index:0 and not the entry which is selected from the table.

How can I resolve this issue ?

Answer 1

You’re doing it backwards anyway, but here is your problem:

pressRecongnizer.view.tag = indexPath.row; // view is nil at this point 
pressRecongnizer.minimumPressDuration = 0.5f; 
[cell addGestureRecognizer:pressRecongnizer]; // now we have a view!
[pressRecongnizer release];

You set the tag on the view of pressRecogniser before you set the view itself. So you are setting a tag to nothing, ending up with zero as the tag and this is the row you keep deleting.

Add a gesture recogniser to your cell when it is first created (if cell==nil) then in your action method get hold of the index path of the cell (UITableView has a method for this, indexPathForCell:), and use that to determine which element you have selected and which element should be deleted.