Update core data object on UITableViewCell touch - ios

Question

I have a simple todo app, where a user can touch a cell to check/uncheck a task. But I am not sure how to update Core Data setting the boolean value of completed to yes.
Here is my code:
//
// PakkelisteViewController.m
// Sommerleir
//
// Created by Ronny-André Bendiksen on 08.05.14.
// Copyright (c) 2014 Arbeidernes Ungdomsfylking. All rights reserved.
//
#import "PakkelisteViewController.h"
#import "AUFToDoItem.h"
#import "TodoCell.h"
#interface PakkelisteViewController ()
#property NSMutableArray *toDoItems;
-(IBAction)addNewToDoItem;
#end
#implementation PakkelisteViewController
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
self.toDoItems = [[NSMutableArray alloc] init];
[self loadInitialData];
// 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.rightBarButtonItem = self.editButtonItem;
}
-(void)viewWillAppear:(BOOL)animated
{
// Fetch the devices from persistent data store
NSManagedObjectContext *managedObjectContext = [self managedObjectContext];
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] initWithEntityName:#"AUFToDoItem"];
self.toDoItems = [[managedObjectContext executeFetchRequest:fetchRequest error:nil] mutableCopy];
[self.tableView reloadData];
}
-(void)loadInitialData
{
// check if user has already been using this functionality
BOOL hasRunBefore = [[NSUserDefaults standardUserDefaults] boolForKey:#"PakkelisteHasRun"];
if (!hasRunBefore)
{
NSLog(#"Has not run");
[self.toDoItems addObjectsFromArray:#[#"Badetøy", #"Skrivesaker", #"Lommepenger", #"Godt humør"]];
[[NSUserDefaults standardUserDefaults] setBool:YES forKey:#"PakkelisteHasRun"];
[[NSUserDefaults standardUserDefaults] synchronize];
}
else
{
NSLog(#"Already run");
}
}
-(IBAction)addNewToDoItem
{
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"Legg til ny" message:nil delegate:self cancelButtonTitle:#"Avbryt" otherButtonTitles:#"Legg til", nil];
[alertView setAlertViewStyle:UIAlertViewStylePlainTextInput];
[[alertView textFieldAtIndex:0] setPlaceholder:#"Rent undertøy"];
[[alertView textFieldAtIndex:0] setAutocapitalizationType:UITextAutocapitalizationTypeSentences];
[alertView show];
}
-(BOOL)alertViewShouldEnableFirstOtherButton:(UIAlertView *)alertView
{
NSString *inputText = [[alertView textFieldAtIndex:0] text];
if ([inputText length] > 0)
{
return YES;
}
else
{
return NO;
}
}
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
if (buttonIndex == 1)
{
NSManagedObjectContext *context = [self managedObjectContext];
// Create a new managed object
NSManagedObject *toDoItem = [NSEntityDescription insertNewObjectForEntityForName:#"AUFToDoItem" inManagedObjectContext:context];
[toDoItem setValue:[alertView textFieldAtIndex:0].text forKey:#"itemName"];
[toDoItem setValue:[NSDate date] forKey:#"creationDate"];
[toDoItem setValue:[NSNumber numberWithBool:YES] forKey:#"completed"];
[self.toDoItems addObject:toDoItem];
NSError *error = nil;
// Save the object to persistent store
if (![context save:&error]) {
NSLog(#"Can't Save! %# %#", error, [error localizedDescription]);
}
[self dismissViewControllerAnimated:YES completion:nil];
[self.tableView reloadData];
}
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
return self.toDoItems.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = #"Cell";
TodoCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil)
{
cell = [[TodoCell alloc] init];
}
NSManagedObject *toDoItem = [self.toDoItems objectAtIndex:indexPath.row];
cell.title.text = [toDoItem valueForKey:#"itemName"];
if ([[toDoItem valueForKey:#"completed"] boolValue] == 1)
{
cell.checkbox.image = [UIImage imageNamed:#"checkbox_on.png"];
}
else
{
cell.checkbox.image = [UIImage imageNamed:#"checkbox_on.png"];
}
return cell;
}
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
/*
[tableView deselectRowAtIndexPath:indexPath animated:NO];
AUFToDoItem *tappedItem = [self.toDoItems objectAtIndex:indexPath.row];
tappedItem.completed = !tappedItem.completed;
[tableView reloadRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationNone];
*/
}
-(NSManagedObjectContext *)managedObjectContext {
NSManagedObjectContext *context = nil;
id delegate = [[UIApplication sharedApplication] delegate];
if ([delegate performSelector:#selector(managedObjectContext)]) {
context = [delegate managedObjectContext];
}
return context;
}
// 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
{
NSManagedObjectContext *context = [self managedObjectContext];
if (editingStyle == UITableViewCellEditingStyleDelete) {
[context deleteObject:[self.toDoItems objectAtIndex:indexPath.row]];
NSError *error = nil;
if (![context save:&error])
{
NSLog(#"Can't delete! %# %#", error, [error localizedDescription]);
return;
}
[self.toDoItems removeObjectAtIndex:indexPath.row];
[self.tableView deleteRowsAtIndexPaths:#[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 - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
// Get the new view controller using [segue destinationViewController].
// Pass the selected object to the new view controller.
}
*/
#end

Answer 1

Change:
tappedItem.completed = !tappedItem.completed;
to:
tappedItem.completed = #(![tappedItem.completed boolValue]);
Which is a minimal code unpacking and re packing of the bool value in an NSNumber instance.
Also, in your if statement, don't check if a BOOL value == 1 because that isn't necessarily true. Just say:
if ([tappedItem.completed]) { ...
You also appear to have a typo in the names of the checkbox images you're using.

Answer 2

What if move the code to update the status of your cell in tableView:tableView didSelectRowAtIndexPath:? In addition, can you explain what you mean with But I am not sure how to update Core Data setting the boolean value of completed to yes?
After updating the status of your managed object you save the context you are using, then you can perfom a reload on the entire table or on a specific index path.
BOOL hasTap = ![tappedItem.completed boolValue];
tappedItem.completed = #(hasTap); // or [NSNumber numberWithBool:hasTap];
// save
// reload
I really follow Jonathan's comment. A NSFetchedResultsController is made to wotk with UITableViews (or UICollectionViews). You can set its delegate, NSFetchedResultsControllerDelegate, to listen and handle for inserting, deleting, moving rows (and section).
An tutorial would be Core Data Tutorial for iOS: How To Use NSFetchedResultsController.