Chapter 8

teamstar · March 15th, 2012, 03:52 PM

I could get the code to work and run successfully but i get this warning to this line

Code:

//â-fired when the user taps on the searchbarâ-
- (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar {    
    isSearchOn = YES;
    canSelectRow = YES;
    
    if (searchBar.text.length>0){Local declaration of 'searchBar' hides instance variable
        self.tableView.scrollEnabled = YES;  
    } else {
        self.tableView.scrollEnabled = NO;
    }
    
    //â-add the Done button at the topâ-
    self.navigationItem.rightBarButtonItem = 
    [[[UIBarButtonItem alloc] 
      initWithBarButtonSystemItem:UIBarButtonSystemItemDone
      target:self  
      action:@selector(doneSearching:)]
     autorelease];
}

This goes to the downloaded code from the author as well.

Secondly, the author showed how we could link the table to another view using

Code:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{

    NSString *message;    
    if (isSearchOn && [searchResult count]>0) { 
        message = [[NSString alloc] initWithFormat:@"You have selected %@", 
                   [searchResult objectAtIndex:indexPath.row]];
    } else {
        NSString *year = [self.years objectAtIndex:[indexPath section]];
        NSArray *movieSection = [self.movieTitles objectForKey:year];
        NSString *movieTitle = [movieSection objectAtIndex:[indexPath row]];    
        message = [[NSString alloc] initWithFormat:@"You have selected %@", movieTitle];
    }

    
    if (!self.detailViewController) {
        self.detailViewController = [[[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil] autorelease];
    }
        
    //â-set the movie selected in the method of the
    // MovieDetailsViewControllerâ-//
    self.detailViewController.detailItem = [message autorelease];
    
    [self.navigationController 
     pushViewController:self.detailViewController 
     animated:YES];
}

How can i link it to another view with a scrollview rather than text message. As in each link has its own scroll view.

thepianoguy · March 15th, 2012, 11:20 PM

There is an instance variable UISearchBar *searchBar. It is also an argument in the delegate method - (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText

This will not cause a problem in the method as implemented, but it is best to avoid having arguments to methods that are the same as ivars. The current practice in header files of have @property declarations only and not separate variable declarations is a way to avoid this. Note how in the RootViewController.h file the DetailViewController is declared as a property only and how its accessor is constructed in the @synthesize. This approach avoids the potential conflict between ivars and method arguments and promotes correct memory management by encouraging the use of accessors when setting ivars. It could be applied to the UISearchBar as follows
1. Eliminate declaration of the UISearchBar *searchBar; between the {}
2. add the IBOutlet macro to the @property as follows:
@property (nonatomic, retain) IBOutlet UISearchBar *searchBar;

3. in the .m file change the @synthesize to
@synthesize searchBar = _searchBar;

4. Change all occasions where the ivar "searchBar" is used to self.searchBar

Now the delegate method signature can be used as written.

It is a good idea to get in the habit of using the @property declarations following the practice demonstrated in the templates. This practice strongly discourages direct setting of ivars, since direct setting can cause problems with memory leaks.

Concerning part 2 of your question:

A UIScrollView can be added to the DetailViewController either in the .xib or programmatically. The detailItem is simply a placeholder to show how an object can be passed in.

Bob