Cannot pass value from UITableViewCell to a detail view - objective-c

Question

I am trying to change the color of a label in my detail view based on which cell is touched in a table view.
I just can't make this happen. Below is my code. I have included the header file from the detail view, and created an IBOutlet for the label.
Update: Ideally, when I clicked on a cell, the label color in detailview should be red. And here is a screencast about my problem. http://www.youtube.com/watch?v=i0nhbsNJWHY&feature=youtube_gdata_player
#pragma mark - TableView Delegate
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[self performSegueWithIdentifier:#"ReferenceDetail" sender:tableView];
}
#pragma mark - Segue
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([[segue identifier] isEqualToString:#"ReferenceDetail"]) {
ReferenceDetailViewController *referenceDetailViewController = [segue destinationViewController];
UIViewController *referenceDetailView = [segue destinationViewController];
if(sender == self.searchDisplayController.searchResultsTableView) {
NSIndexPath *indexPath = [self.searchDisplayController.searchResultsTableView indexPathForSelectedRow];
NSString *destinationTitle = [[filteredReferenceArray objectAtIndex:[indexPath row]] name];
[referenceDetailView setTitle:destinationTitle];
}
else {
NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
NSString *destinationTitle = [[referenceArray objectAtIndex:[indexPath row]] name];
[referenceDetailView setTitle:destinationTitle];
[referenceDetailViewController.label1 setTextColor:[UIColor redColor]];
}
}
}

Answer 1

The problem you are having is that the outlet UILabel inside your ReferenceDetailViewController has not loaded up from the xib, yet you are trying to set it's textColor property.
As a way to make sure this is the problem, try setting a breakpoint in the line where you set the color and another breakpoint inside the ReferenceDetailViewController [viewDidLoad] method. The line where you setup the color should be getting called first.
A simple solution to your problem is to have a property on your ReferenceDetailViewController class that "holds" the UIColor instance and later set it on the viewDidLoad method:
// ...
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([[segue identifier] isEqualToString:#"ReferenceDetail"]) {
ReferenceDetailViewController *referenceDetailViewController = [segue destinationViewController];
UIViewController *referenceDetailView = [segue destinationViewController];
NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
NSString *destinationTitle = [[referenceArray objectAtIndex:[indexPath row]] name];
[referenceDetailView setTitle:destinationTitle];
referenceDetailViewController.auxTextColor = [UIColor redColor];
}
// ..
And in ReferenceDetailViewController:
#interface ReferenceDetailViewController : UIViewController
#property (retain, nonatomic) UIColor *auxTextColor;
// ...
#end
#implementation ReferenceDetailViewController
- (void)viewDidLoad
{
[super viewDidLoad];
label1.textColor = self.auxTextColor;
// ...
}
#end
If you must do this for a set of labels, it'd be wise to have a NSDictionary object to hold these properties for you.

Answer 2

The outlets are not setup yet when you segue so you can't get to them to change them. Try sending some object or something over and in the viewdidload of the viewcontroller you segue to you read that and then use that as the way to know what color to change to and then in that same code you change the color of the label.