UINavigationController and Duplication

Hello all!

I'm using a UINavigationController and I want to reuse a UITableView. To that end, I've made the data sources for the table properties. Here are the files for the view.

WordList.h:

Code:

    
@interface WordList : UIViewController <UITableViewDelegate, UITableViewDataSource,   UISearchBarDelegate>{
    }

    @property (nonatomic, retain) IBOutlet UIViewController *selfRef;
    @property (assign) NSDictionary *wordList;
    @property (assign) NSArray *indexList;
    @property (assign) UINavigationController *useNC;


    - (void)setNavigationController:(UINavigationController *)nc;
    - (void)setSource:(NSString *)source;
    - (void)dealloc;

    @end

WordList.m:

Code:

    @implementation WordList

    @synthesize selfRef;
    @synthesize wordList;
    @synthesize indexList;
    @synthesize useNC;

    //static NSDictionary *wordList = nil;
    //static NSArray *indexList = nil;
    //static UINavigationController *useNC;

    - (void)awakeFromNib {
      self.title = @"English -> ASL";
    }
    
    - (void)viewDidLoad {
      if (!wordList){
        Database *db = [Database singleton];
      
        if (db) wordList = [db getWordList];
        
        indexList = [wordList allKeys];/*[NSArray arrayWithObjects:@"A", @"B", @"C", @"D", @"E", @"F", @"G", @"H", @"I", @"J", @"K", @"L", @"M", 
                                        @"N", @"O", @"P", @"Q", @"R", @"S", @"T", @"U", @"V", @"W", @"X", @"Y", @"Z", nil];*/
        
        [wordList retain];
        [indexList retain];
      }
    }
    
    - (void)setSource:(NSString *)source {
      Database *db = [Database singleton];
      
      NSLog(@"%@:setSource", self);
      
      if (db) wordList = [db runWordListQuery:source];
      
      NSLog(@"Word list: %@", wordList);
      
      indexList = [wordList allKeys];/*[NSArray arrayWithObjects:@"A", @"B", @"C", @"D", @"E", @"F", @"G", @"H", @"I", @"J", @"K", @"L", @"M", 
                                      @"N", @"O", @"P", @"Q", @"R", @"S", @"T", @"U", @"V", @"W", @"X", @"Y", @"Z", nil];*/
      
      NSLog(@"Index list: %@", indexList);
    
      [wordList retain];
      [indexList retain];
    }  
    
    - (void)setNavigationController:(UINavigationController *)nc {
      NSLog(@"%@:setNavigationController(%@)", self, nc);
      
      useNC = nc;
    }
    
    - (void)dealloc {
      NSLog(@"WordList:dealloc");
    
      if (wordList) [wordList release];
      if (indexList) [indexList release];
      
      [super dealloc];
    }
    
    - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
      EntryViewer *ev = [[EntryViewer alloc] initWithNibName:@"EntryViewer" bundle:nil];
      if (ev){
        [[tableView cellForRowAtIndexPath:indexPath] setSelected:NO animated:YES];
        
        [ev setEntry:[[[wordList objectForKey:[indexList objectAtIndex:indexPath.section]] objectAtIndex:indexPath.row] ident]];
        
        if (useNC){
          [useNC pushViewController:ev animated:YES];
        }
        else {
          [APP_LISTNAV pushViewController:ev animated:YES];
        }
        
        [ev release];
      }
    }
    
    - (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView {
      return indexList;
    }
    
    - (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
      return [indexList objectAtIndex:section];
    }
    
    - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
      NSLog(@"%@:numberOfSectionInTableView(%u): %@", self, [indexList count], indexList);
      
      return [indexList count];
    }
    
    - (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(NSString *)title atIndex:(NSInteger)index {
      NSInteger section = -1;
      
      section = [indexList indexOfObject:title];
      
      return section;
    }
    
    - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
      // Return the number of rows in the section.
      
      return [[wordList objectForKey:[indexList objectAtIndex:section]] count];
    }
    
    
    // Customize the appearance of table view cells.
    - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
      NSString *CellIdentifier = [[[wordList objectForKey:[indexList objectAtIndex:indexPath.section]] objectAtIndex:indexPath.row] description];
      
      UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
      if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
        cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
      }
      
      cell.textLabel.text = CellIdentifier;
      
      return cell;
    }
    
    @end

I'm still finding my feet in regards to Objective-C properties so I may be misusing them. The problem is that, even though the assignments in setSource: work, the table shows no data. Please see the NSLog() output below.

It's clear why the table shows no data, the call to `numberOfSectionsInTable:` returns 0. What I want to know is why. I'm pretty certain, as you can see from the log, that it's because the value of `self` is different from the previous two calls. Why is this? The third call comes after the call to `pushViewController:`. Is that the reason? Am I approaching this wrong or have I missed something simple?

Thank you for your time.

 

It was my understanding that using the @property/@synthesize constructions automatically handled the creation of variables.

If you're referring to the calls to [wordList retain] in viewDidLoad: and setSource: you'll notice that I only retain when I've created a new WordList. In viewDidLoad: I check to see if wordList has been created yet, if so, the retain call is never reached.

The problem, I think, considering the contents of the debugging log, is the change of instance between the second-to-last and last calls. You can see that the first call:
2011-10-17 10:58:22.396 ASL Dictionary[381:207] <WordList: 0x614f0b0> - WorldList:setNavigationController(<UINavigationController: 0x573e780>)

is on a different instance from the second call:
2011-10-17 10:58:22.402 ASL Dictionary[381:207] <WordList: 0x57806f0> - numberOfSectionInTableView(0): (null)