How to keep the checkmark in a UITableView after the view disappears - iphone

Question

I have a uitableview that's displaying multiple selections with a custom checkmark. When selected the rows value is save using NSUserDefaults. The problem is that despite the values being saved the checkmarks disappear from the table cell rows. I can't figure out why.
thanks for any help, I'm really stuck on this.
Here's the .h code:
#interface CategoriesViewController : UITableViewController {
NSString *selectedCategoryTableString;
NSString *jsonStringCategory;
int prev;
}
// arForTable array will hold the JSON results from the api
#property (nonatomic, retain) NSArray *arForTable;
#property (nonatomic, retain) NSMutableArray *arForIPs;
#property (nonatomic, retain) NSMutableArray *categorySelected;
#property (nonatomic, retain) NSString *jsonStringCategory;
#property(nonatomic, retain) UIView *accessoryView;
#end
and the .m code:
#implementation CategoriesViewController
#synthesize jsonStringCategory;
#synthesize arForTable = _arForTable;
#synthesize arForIPs = _arForIPs;
- (void)viewDidLoad
{
[super viewDidLoad];
self.arForIPs=[NSMutableArray array];
self.categorySelected = [[NSMutableArray alloc] init];
[self reloadMain];
self.tableView.allowsMultipleSelection = YES;
}
-(void) reloadMain {
jsonString = #"http:///******";
// Download the JSON
NSString *jsonString = [NSString
stringWithContentsOfURL:[NSURL URLWithString:jsonString]
encoding:NSStringEncodingConversionAllowLossy|NSUTF8StringEncoding
error:nil];
NSMutableArray *itemsTMP = [[NSMutableArray alloc] init];
// Create parser
SBJSON *parser = [[SBJSON alloc] init];
NSDictionary *results = [parser objectWithString:jsonString error:nil];
itemsTMP = [results objectForKey:#"results"];
self.arForTable = [itemsTMP copy];
[self.tableView reloadData];
}
#pragma mark - Table view data source
- (int)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (int)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [self.arForTable 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];
[cell.textLabel setFont:[UIFont fontWithName: #"Asap-Bold" size: 14.0f]];
[cell.detailTextLabel setFont:[UIFont fontWithName: #"Asap-Bold" size: 14.0f]];
cell.accessoryView.hidden = NO;
}
UIImageView *cellAccessoryImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"icon-tick.png"]] ;
UIImageView *cellAccessoryNoneImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#""]] ;
if([self.arForIPs containsObject:indexPath]){
cell.accessoryView = cellAccessoryImageView;
} else {
cell.accessoryView = cellAccessoryNoneImageView;
}
// Get item from tableData
NSDictionary *item = (NSDictionary *)[_arForTable objectAtIndex:indexPath.row];
// encoding fix
NSString *utf8StringTitle = [item objectForKey:#"name"];
NSString *correctStringTitle = [NSString stringWithCString:[utf8StringTitle cStringUsingEncoding:NSISOLatin1StringEncoding] encoding:NSUTF8StringEncoding];
cell.textLabel.text = [correctStringTitle capitalizedString];
NSNumber *num = [item objectForKey:#"id"];
cell.detailTextLabel.text = [num stringValue];
cell.detailTextLabel.hidden = YES;
return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[tableView deselectRowAtIndexPath:indexPath animated:YES];
if([self.arForIPs containsObject:indexPath]){
[self.arForIPs removeObject:indexPath];
[self.categorySelected removeObject:[[self.arForTable objectAtIndex:indexPath.row] objectForKey:#"id"]];
} else {
[self.arForIPs addObject:indexPath];
[self.categorySelected addObject:[[self.arForTable objectAtIndex:indexPath.row] objectForKey:#"id"]];
NSLog(#"%# categorySelected",self.categorySelected);
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSLog(#"%# defaults categorySelected",[defaults arrayForKey:#"selectedCategoryTableString"]);
NSString *string = [self.categorySelected componentsJoinedByString:#","];
[defaults setObject:string forKey:#"selectedCategoryTableString"];
NSLog(#"%# STRING",string);
}
[tableView reloadData];
}
-(void) viewWillAppear:(BOOL)animated {
[super viewWillAppear:NO];
[self.navigationController setNavigationBarHidden:YES animated:NO];
self.navigationController.toolbarHidden = YES;
}

Answer 1

First of all your code has lots of memory leaks, please do use the static analyzer and/or instruments to fix them, few for them are pretty obvious like you initialized the SBJSON parser and did not release it, itemsTMP is another.
I have rewritten your code to be much more efficient and memory friendly:
#interface CategoriesViewController : UITableViewController
{
NSArray *_items;
NSMutableArray *_selectedItems;
UIImageView *cellAccessoryImageView;
}
#end
#implementation CategoriesViewController
- (void)viewDidLoad
{
[super viewDidLoad];
_selectedItems = [NSMutableArray new];
cellAccessoryImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"icon-tick.png"]] ;
[self reloadMain];
self.tableView.allowsMultipleSelection = YES;
}
- (void)reloadMain
{
NSString *jsonString = #"http:///******";
// Download the JSON
jsonString = [NSString
stringWithContentsOfURL:[NSURL URLWithString:jsonString]
encoding:NSStringEncodingConversionAllowLossy|NSUTF8StringEncoding
error:nil];
// Create parser
SBJSON *parser = [SBJSON new];
NSDictionary *results = [parser objectWithString:jsonString error:nil];
if (_items) [_items release];
_items = [[results objectForKey:#"results"] copy];
[parser release];
[self.tableView reloadData];
}
#pragma mark - Table view data source
- (int)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (int)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [_items 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 setFont:[UIFont fontWithName: #"Asap-Bold" size: 14.0f]];
[cell.detailTextLabel setFont:[UIFont fontWithName: #"Asap-Bold" size: 14.0f]];
cell.accessoryView.hidden = NO;
}
NSDictionary *item = [_items objectAtIndex:indexPath.row];
if ([_selectedItems containsObject:item])
{
// preloaded image will help you have smoother scrolling
cell.accessoryView = cellAccessoryImageView;
}
else
{
cell.accessoryView = nil;
cell.accessoryType = UITableViewCellAccessoryNone;
}
// Get item from tableData
cell.textLabel.text = [[NSString stringWithCString:[[item objectForKey:#"name"] cStringUsingEncoding:NSISOLatin1StringEncoding] encoding:NSUTF8StringEncoding] capitalizedString];
cell.detailTextLabel.text = [[item objectForKey:#"id"] stringValue];
cell.detailTextLabel.hidden = YES;
item = nil;
return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
NSDictionary *item = [_items objectAtIndex:indexPath.row];
if ([_selectedItems containsObject:item])
{
[_selectedItems removeObject:item];
}
else
{
[_selectedItems addObject:item];
}
item = nil;
[tableView reloadRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
}
- (void)dealloc
{
[_selectedItems release];
[cellAccessoryImageView release];
[super dealloc];
}
#end

Answer 2

Since in your table there is only one section. Try this approach and this will help you certainly.
In - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath write following code;
if([self.arForIPs containsObject:[NSNumber numberWithInt:indexPath.row]]){
cell.accessoryView = cellAccessoryImageView;
} else {
cell.accessoryView = cellAccessoryNoneImageView;
}
And in - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath write code as below,
if([self.arForIPs containsObject:[NSNumber numberWithInt:indexPath.row]]){
[self.arForIPs removeObject:[NSNumber numberWithInt:indexPath.row]];
} else {
[self.arForIPs addObject:[NSNumber numberWithInt:indexPath.row]]
}