Saving values in UITableCellView to custom class - ios

Question

I have an iOS app that makes a request to a web-service which returns JSON formatted data. There is a predefined class in my iOS app that inherits and implements the JSONModel Framework, to which this returned data is bound to as an NSMutableArray containing these objects. The TableView's data is generated from these objects.
My conundrum is that in my custom UITableViewCell I allow the user to change some of the data presented, and I need the ability to save that back to the classes which can be serialized and sent via POST back to the web-service.
Custom Cell .h:
#interface EnclosureDetailCell : UITableViewCell
#property (weak, nonatomic) IBOutlet UILabel *enclosureNumber;
#property (weak, nonatomic) IBOutlet UITextField *QTY;
#property (weak, nonatomic) IBOutlet UIStepper *stepper;
#property (weak, nonatomic) IBOutlet DeSelectableSegmentControl *enclosureStatus;
- (IBAction)valueChanged:(UIStepper *)sender;
- (IBAction)changedTextValue:(id)sender;
#end
Custom Cell .m:
#implementation EnclosureDetailCell
- (IBAction)changedTextValue:(id)sender
{
self.stepper.value = self.QTY.text.intValue;
}
- (IBAction)valueChanged:(UIStepper *)sender
{
int stepperValue = sender.value;
self.QTY.text = [NSString stringWithFormat:#"%i", stepperValue];
}
- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
if (self) {
// Initialization code
}
return self;
}
- (void)setSelected:(BOOL)selected animated:(BOOL)animated
{
[super setSelected:selected animated:animated];
// Configure the view for the selected state
}
#end
Model Class (.h):
#protocol Enclosure #end
#interface Enclosure : JSONModel
#property (nonatomic, strong) NSString *EnclosureNumber;
#property (nonatomic, strong) NSString *InventoryID;
#property (nonatomic, strong) NSString *UseInventoryID;
#property (nonatomic) int CensusQTY;
#property (nonatomic) BOOL Verified;
#property (nonatomic) BOOL MissingEnclosure;
#property (nonatomic) BOOL RetireEnclosure;
#end
TableViewController (partial)
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
EnclosureDetailCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
ProtocolEnclosure *loc = (ProtocolEnclosure *)_objects[indexPath.section];
Enclosure *enc = (Enclosure *) loc.Enclosures[indexPath.row];
cell.enclosureNumber.text = enc.EnclosureNumber;
cell.QTY.text =[NSString stringWithFormat:#"%i", enc.CensusQTY];
cell.stepper.value = enc.CensusQTY;
if (enc.Verified)
{
cell.QTY.enabled = false;
cell.stepper.enabled = false;
cell.enclosureStatus.selectedSegmentIndex = Verified;
}
else if (enc.MissingEnclosure)
cell.enclosureStatus.selectedSegmentIndex = MissingEnclosure;
else if (enc.RetireEnclosure)
cell.enclosureStatus.selectedSegmentIndex = RetireEnclosure;
else
cell.enclosureStatus.selectedSegmentIndex = None;
return cell;
}
enum{
Verified = 0,
MissingEnclosure = 1,
RetireEnclosure = 2,
None = -1
};
So in my UITableViewCell I have a text field that corresponds to CensusQTY and a SegmentControl who's selection corresponds to Verified/MissingEnclosure/RetireEnclosure.
How can I go about saving the data the user has changed via the UI back into the model class?
I obviously can't iterate over each of the UITableView rows - because of dequeue, I will only get the ones that are currently on screen.
Any thoughts on how this could be accomplished?
Thanks!

Answer 1

There are probably many ways to do that, the cleanest way that comes to mind would be to create a delegate for your custom cell. (That you could declare in .h). Your cell should add a index property to keep track of what instance of Enclosure it's referring to.
#class EnclosureDetailCell;
#protocol EnclosureCellDelegate
#required
- (void) qtyDidUpdate:(EnclosureDetailCell*)cell;
- (void) stepperDidUpdate:(EnclosureDetailCell*)cell;
#end
#interface EnclosureDetailCell : UITableViewCell
#property (nonatomic,assign) NSInteger index;
#property (nonatomic,weak) id<EnclosureCellDelegate> delegate;
....
In your .m you would have to call your delegate
#implementation EnclosureDetailCell
- (IBAction)changedTextValue:(id)sender
{
self.stepper.value = self.QTY.text.intValue;
[self.delegate qtyDidUpdate:self];
}
- (IBAction)valueChanged:(UIStepper *)sender
{
int stepperValue = sender.value;
self.QTY.text = [NSString stringWithFormat:#"%i", stepperValue];
[self.delegate stepperDidUpdate:self];
}
You'd have to implement those methods in your TableViewController. It would look like :
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
EnclosureDetailCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
cell.index = indexPath.row;
cell.delegate = self;
ProtocolEnclosure *loc = (ProtocolEnclosure *)_objects[indexPath.section];
Enclosure *enc = (Enclosure *) loc.Enclosures[indexPath.row];
....
}
- (void) qtyDidUpdate:(EnclosureDetailCell*)cell{
Enclosure *enc = (Enclosure *)loc.Enclosures[cell.index];
//Here you can update directly the items of your array
}
- (void) stepperDidUpdate:(EnclosureDetailCell*)cell{
Enclosure *enc = (Enclosure *)loc.Enclosures[cell.index];
//Here you can update directly the items of your array
}
That way you will be able to keep your whole array updated, and be able to send your new data to your web service whenever you like.

Answer 2

Probably the easiest way would be to have the cell own a weak reference to the Model object which you update in the IBAction methods of the cell.
#interface EnclosureDetailCell : UITableViewCell
...
#property(nonatomic, weak) Enclosure *enclosure;
...
#end
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
...
Enclosure *enc = (Enclosure *) loc.Enclosures[indexPath.row];
cell.enclosure = enc;
...
}
#implementation EnclosureDetailCell
- (IBAction)changedTextValue:(id)sender
{
self.stepper.value = self.QTY.text.intValue;
//you have access to self.enclosure, do what you want
}
- (IBAction)valueChanged:(UIStepper *)sender
{
int stepperValue = sender.value;
self.QTY.text = [NSString stringWithFormat:#"%i", stepperValue];
//you have access to self.enclosure, do what you want
}