Passing data from Detail to Master

Question

Hey there,
I have a TableViewController that has 3 cells, including a subtitle, with disclosure indicators.
When one is tapped, another TableViewController opens with cells showing values from an array, and with check marks.
Is there anyway to pass the value of the cell that the checkmark was chosen to the previous(Root)TableViewController's subtitle, so when the user taps back, they will see the value they checked on the first TableViewController cell's subtitle?
OR is there an better way to do it than pass it to a subtitle from a previous screen?
The reason I want to do this is I want all 3 cells' subtitles in the Root TableViewController to be filled with the users choice, then I have a button on the Root TableViewController that when tapped, searches a database using the choices in the subtitles.
Thanks in advance!

Answer 1

The best way to pass data between view controllers is to make your model accessible to both.
Do not use UI controls to store attributes.  UI control values should just reflect the model.
Example of one way to do this.
Assume your model is a class.  This sample has one property.
@interface Options : NSObject
@property (copy, nonatomic) NSString *color;
@end
Make the model available to parent and child view controllers. Either a property on the AppDelegate or properties on each view controller.
@property (strong, nonatomic) Options *options;
If the property is on view controllers, set it when pushing child view controllers.
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
    if ([[segue identifier] isEqualToString:@"ShowColorSelector"]) {
        [[segue destinationViewController] setOptions:options];
The child view controller can then directly set model properties.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
    options.color = [availableColors objectAtIndex:indexPath.row];
The parent view controller can update UI controls from the model when it is shown. This example uses static table view content, not cell prototypes; colorCellLabel is a an IBOutlet for the subtitle on one of the cells.
- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
    if (viewController == self) {
        colorCellLabel.text = options.color ? options.color : @"not set";