Persisting Checklists on a UITableView using NSUserDefults - iphone

Question

I have a very simple table view which shows a list of days. Once the user selects which days are relevant to them this data is saved in NSUserdefaults. I then need the check marks to remain once the user has exited then re-entered the table view.
I am very close to getting my desired functionality - I can save the array of check marked items and get it to persist using NSUserDefaults but I don't know how to make these selections persist (keep a check mark next to the selected item) once a user has exited then re-entered the table view.
I know that I need to edit the cellForRowAtIndexPath method but I am not sure exactly what to do. Any help would be greatly appreciated.
I have attached my code below:
#import "DayView.h"
#implementation DayView
#synthesize sourceArray;
#synthesize selectedArray;
- (id)init
{
self = [super initWithStyle:UITableViewStyleGrouped];
if (self) {
// Custom initialization
[[self navigationItem] setTitle:#"Days"];
[[self tableView] setBackgroundColor:[UIColor clearColor]];
}
return self;
}
- (void)viewWillDisappear:(BOOL)animated
{
// create a standardUserDefaults variable
NSUserDefaults * standardUserDefaults = [NSUserDefaults standardUserDefaults];
// Convert array to string
NSString *time = [[selectedArray valueForKey:#"description"] componentsJoinedByString:#","];
// saving an NSString
[standardUserDefaults setObject:time forKey:#"string"];
NSLog(#"Disapear: %#", time);
}
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
#pragma mark - View lifecycle
- (void)viewDidLoad {
[super viewDidLoad];
// create a standardUserDefaults variable
NSUserDefaults * standardUserDefaults = [NSUserDefaults standardUserDefaults];
// getting an NSString object
NSString *myString = [standardUserDefaults stringForKey:#"string"];
NSLog(#"Appear: %#", myString);
NSMutableArray * tempArray = [[NSMutableArray alloc] init];
[self setSelectedArray:tempArray];
[tempArray release];
NSArray * tempSource = [[NSArray alloc] initWithObjects:#"Monday", #"Tuesday", #"Wednesday", #"Thursday", #"Friday", #"Saturday",nil];
[self setSourceArray:tempSource];
[tempSource release];
[self.tableView reloadData];
}
#pragma mark -
#pragma mark Table view data source
// Customize the number of sections in the table view.
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
// Customize the number of rows in the table view.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [self.sourceArray count];;
}
// Customize the appearance of table view cells.
- (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];
}
NSString *time = [sourceArray objectAtIndex:indexPath.row];
cell.textLabel.text = time;
if ([self.selectedArray containsObject:[self.sourceArray objectAtIndex:indexPath.row]])
{
[cell setAccessoryType:UITableViewCellAccessoryCheckmark];
}
else
{
[cell setAccessoryType:UITableViewCellAccessoryNone];
}
NSLog(#"Selected Days: %#", selectedArray);
return cell;
}
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
return #"Which times you are available?";
}
#pragma mark -
#pragma mark Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if ([self.selectedArray containsObject:[self.sourceArray objectAtIndex:indexPath.row]]){
[self.selectedArray removeObjectAtIndex:[self.selectedArray indexOfObject: [self.sourceArray objectAtIndex:indexPath.row]]];
}
else
{
[self.selectedArray addObject:[self.sourceArray objectAtIndex:indexPath.row]];
}
[tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationNone];
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#end

Answer 1

Create your tempSource as follows:
NSMutableArray * tempSource = [[NSMutableArray alloc] init];
NSArray *daysOfWeek = [NSArray arrayWithObjects:#"Monday", #"tuestay", #"wednesday", #"thursday", #"friday", #"saturday", #"sunday",nil];
for (int i = 0; i < 7; i++)
{
NSString *dayOfWeek = [daysOfWeek objectAtIndex:i];
NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:dayOfWeek, #"day", [NSNumber numberWithBool:NO], #"isSelected",nil];
[tempSource addObject:dict];
}
[self setSourceArray:tempSource];
[tempSource release];
Then use this Array in cellForRow and didSelect as follows:
cellForRow
NSDictionary *dayOfWeekDictionary = [sourceArray objectAtIntex:indexPath.row];
cell.textLabel.text = [dayOfWeekDictionary objectForKey:#"day"];
if ([[dayOfWeekDictionary objectForKey:#"isSelected"] boolValue])
[cell setAccessoryType:UITableViewCellAccessoryCheckmark];
else
[cell setAccessoryType:UITableViewCellAccessoryNone];
didSelect
NSDictionary *dayOfWeekDictionary = [sourceArray objectAtIntex:indexPath.row];
if ([[dayOfWeekDictionary objectForKey:#"isSelected"] boolValue])
[dayOfWeekDictionary setObject:[NSNumber numberWithBool:NO] forKey:#"isSelected"];
else
[dayOfWeekDictionary setObject:[NSNumber numberWithBool:YES] forKey:#"isSelected"];
To save this Array use this statement:
[[NSUserDefaults standardUserDefaults] setObject:sourceArray forKey:#"array"];