Need Help Deleting Data From UITableView - iphone

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.

Answer 2

What type is self.list? It needs to be an NSMutableArray for a call to 'removeObjectAtIndex' to be valid.

Answer 3

There is no .plist involved here, that's just the name of this NSMutableArray. Your sample code assumes you are declaring an NSMutableArray called list in your #interface...
#interface RoutineTableViewController : UIViewController {
NSMutableArray *list;
}
#property (nonatomic, retain) NSMutableArray *list;
#end
... and synthesizing it (and filling it with something) somewhere in your code.