Question

I am trying to make my UITableView Editable but I’m having some trouble with the code, specifically with the commitEditingStyle method. It is not working I think the method I have is only for plist and not for an array by itself.

#import "RoutineTableViewController.h"
#import "AlertPrompt.h"

@implementation RoutineTableViewController
@synthesize myArray;

- (void)dealloc
{
    [super dealloc];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    myArray = [[NSMutableArray alloc] init]; 
    myData = [[NSMutableArray arrayWithContentsOfFile:@"mydata"] retain]; 

    if (myData == nil)
    {
        myData = [NSMutableArray array];  
    }

    [super viewDidLoad];

    UIBarButtonItem * addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(showPrompt)];
    [self.navigationItem setLeftBarButtonItem:addButton];
    [addButton release];

    self.navigationItem.rightBarButtonItem = self.editButtonItem;
}

-(void)showPrompt
{
    AlertPrompt *prompt = [AlertPrompt alloc];
    prompt = [prompt initWithTitle:@"Add Workout Day" message:@"\n \n Please enter title for workout day" delegate:self cancelButtonTitle:@"Cancel" okButtonTitle:@"Add"];

    [prompt show];
    [prompt release];
}

- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex
{
    if (buttonIndex != [alertView cancelButtonIndex])
    {
        NSString *entered = [(AlertPrompt *)alertView enteredText];
        NSLog([NSString stringWithFormat:@"%@", entered]);
        if(myData && entered)
        {
            [myArray addObject:entered];
            [tableView reloadData];
        }
    }
}

- (void)viewDidUnload
{
    [super viewDidUnload];
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
}

- (void)viewDidDisappear:(BOOL)animated
{
    [super viewDidDisappear:animated];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

#pragma mark - Table view data source

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

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [myArray count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    }
    cell.textLabel.text = [self.myArray objectAtIndex:indexPath.row];

    return cell;
}


/*
// 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
{

    NSUInteger row = [indexPath row];
    [self.list removeObjectAtIndex:row];
    [tableView deleteRowsAtIndexPaths:[myArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];

Answer 1

As prevoulsy ansewered; self.list has to be Mutable.

The next thing you need to do is “warn” the tableView about the updates.

So you would do it like this:

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{

    NSUInteger row = [indexPath row];
    [self.list removeObjectAtIndex:row];
    //Notice we "warn" the tableView
    [tableView beginUpdates];
    [tableView deleteRowsAtIndexPaths:[NSMutableArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
    //We also tell the table the updates are done so it can do the proper animations
    [tableView endUpdates];
}

Remember you first change the model and then update the tableView with the add, reload and delete methods in between a beginUpdates and endUpdates.