title: iOS TableView crash loading different data
body: <p>I'm developing a simple iOS app where there is a table view with some categories (CategoryViewController).
  When clicking one of this category the view will be passed to a RecipesListController with another table view with recipes. This recipes are loaded from different plist based on the category clicked.</p>
  
  <p>The first time I click on a category, the recipes list is loaded and shown correctely. If i back to the category list and click any of the category (also the same again) the app crash. And I don't know how. The <code>viewWillAppear</code> is ececuted correctely but after crash.</p>
  
  <p>Can you help me?
  If you need the entire project I can zip it for you. Ok?</p>
  
  <p>Here is the code of the CategoryViewController.h</p>
  
  <pre><code>#import &lt;Foundation/Foundation.h&gt;
  #import "RecipeRowViewController.h"
  
  @class RecipesListController;
  
  @interface CategoryViewController : UITableViewController {
  
      NSArray *recipeCategories;
      RecipesListController *childController;
  }
  
  @property (nonatomic, retain) NSArray *recipeCategories;
  
  @end
  </code></pre>
  
  <p>The CategoryViewControoler.m</p>
  
  <pre><code>#import "CategoryViewCotroller.h"
  #import "NavAppDelegate.h"
  #import "RecipesListController.h"
  
  
  @implementation CategoryViewController
  
  @synthesize recipeCategories; 
  
  
  
  - (void)viewDidLoad {
  
      // Create the categories
      NSArray *array = [[NSArray alloc] initWithObjects:@"Antipasti", @"Focacce", @"Primi", @"Secondi", @"Contorni", @"Dolci", nil];
      self.recipeCategories = array;
      [array release];
  
      // Set background image
      UIImageView *bgImg = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"sfondo_app.png"]];
      [self.tableView setBackgroundView:bgImg];
      [bgImg release];
  
      [self.tableView reloadData];
      [super viewDidLoad];
  }
  
  
  
  - (void)viewDidUnload {
  
      self.recipeCategories = nil;
  //  [childController release];
      [super viewDidUnload];
  }
  
  
  
  - (void)dealloc {
  
      [recipeCategories release];
  //  [childController release];
      [super dealloc];
  }
  
  
  
  
  #pragma mark -
  #pragma mark Table data source methods
  
  - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
  
      return [recipeCategories count];
  }
  
  
  
  - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
  
      static NSString *CellId = @"RecipesCategoriesCellId";
  
      // Try to reuse a cell or create a new one
      UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellId];
      if (cell == nil) {
  
          cell = [[[UITableViewCell alloc]
                   initWithStyle:UITableViewCellStyleDefault
                   reuseIdentifier:CellId] autorelease];
      }
  
      // Get the right value and assign to the cell
      NSUInteger row = [indexPath row];
      NSString *rowString = [recipeCategories objectAtIndex:row];
      cell.textLabel.text = rowString;
      cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
      [rowString release];
  
      return cell;
  }
  
  
  
  #pragma mark -
  #pragma mark Table view delegate methods
  
  - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
  
      if (childController == nil) {
          childController = [[RecipesListController alloc] initWithStyle:UITableViewStyleGrouped];
      }
  
      childController.title = @"Ricette";
      childController.category = [indexPath row];
  
      [self.navigationController pushViewController:childController animated:YES];
  }
  
  
  
  @end
  </code></pre>
  
  <p>The RecipesListController.h</p>
  
  <pre><code>#import &lt;Foundation/Foundation.h&gt;
  #import "RecipeRowViewController.h"
  
  #define kRecipeArrayLink        0
  #define kRecipeArrayDifficulty  1
  #define kRecipeArrayFoodType    2
  
  
  #define kRecipeAntipasti    0
  #define kRecipeFocacce      1
  #define kRecipePrimi        2
  #define kRecipeSecondi      3
  #define kRecipeContorni     4
  #define kRecipeDolci        5
  
  
  @class DisclosureDetailController;
  
  @interface RecipesListController : UITableViewController {
  
      NSInteger category;
      NSDictionary *recipesArray;
      NSArray *recipesNames;
      NSArray *recipesLinks;
      DisclosureDetailController *childController;
  }
  
  @property (nonatomic) NSInteger category;
  @property (nonatomic, retain) NSDictionary *recipesArray;
  @property (nonatomic, retain) NSArray *recipesNames;
  @property (nonatomic, retain) NSArray *recipesLinks;
  
  @end
  </code></pre>
  
  <p>The RecipesListcontroller.m</p>
  
  <pre><code>#import "RecipesListController.h"
  #import "NavAppDelegate.h"
  #import "DisclosureDetailController.h"
  
  
  @implementation RecipesListController
  
  @synthesize category, recipesArray, recipesNames, recipesLinks;
  
  
  
  - (void)viewDidLoad {
  
      // Set background image
      UIImageView *bgImg = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"sfondo_app.png"]];
      [self.tableView setBackgroundView:bgImg];
      [bgImg release];
  
      [self.tableView reloadData];
  
      [super viewDidLoad];
  }
  
  
  
  - (void)viewWillAppear:(BOOL)animated {
  
      if (self.recipesArray != nil) {
  
          // Release the arrays
          [self.recipesArray release];
          [self.recipesNames release];
      }
  
      // Load the dictionary
      NSString *path = nil;
  
      // Load a different dictionary, based on the category
      if (self.category == kRecipeAntipasti) {
          path = [[NSBundle mainBundle] pathForResource:@"recipes_antipasti" ofType:@"plist"];
  
      } else if (self.category == kRecipeFocacce) {
          path = [[NSBundle mainBundle] pathForResource:@"recipes_focacce" ofType:@"plist"];
  
      } else if (self.category == kRecipePrimi) {
          path = [[NSBundle mainBundle] pathForResource:@"recipes_primi" ofType:@"plist"];
  
      } else if (self.category == kRecipeSecondi) {
          path = [[NSBundle mainBundle] pathForResource:@"recipes_secondi" ofType:@"plist"];
  
      } else if (self.category == kRecipeContorni) {
          path = [[NSBundle mainBundle] pathForResource:@"recipes_contorni" ofType:@"plist"];
  
      } else if (self.category == kRecipeDolci) {
          path = [[NSBundle mainBundle] pathForResource:@"recipes_dolci" ofType:@"plist"];
      }
  
      NSDictionary *dict = [[NSDictionary alloc] initWithContentsOfFile:path];
      self.recipesArray = dict;
      [dict release];
  
      // Save recipes names
      NSArray *array = [[recipesArray allKeys] sortedArrayUsingSelector:
                        @selector(compare:)];
      self.recipesNames = array;
  
      [self.tableView reloadData];
      [super viewWillAppear:animated];
  }
  
  
  - (void)viewDidUnload {
  
      self.recipesArray = nil;
      self.recipesNames = nil;
      self.recipesLinks = nil;
  //  [childController release];
      [super viewDidUnload];
  }
  
  
  
  - (void)dealloc {
  
      [recipesArray release];
      [recipesNames release];
      [recipesLinks release];
  //  [childController release];
      [super dealloc];
  }
  
  
  
  
  #pragma mark -
  #pragma mark Table data source methods
  
  - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
  
      return [recipesNames count];
  }
  
  
  
  - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
  
      static NSString *RecipesListCellId = @"RecipesListCellId";
  
      // Try to reuse a cell or create a new one
      UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:RecipesListCellId];
      if (cell == nil) {
  
          cell = [[[UITableViewCell alloc]
                  initWithStyle:UITableViewCellStyleDefault
                  reuseIdentifier:RecipesListCellId] autorelease];
      }
  
      // Get the right value and assign to the cell
      NSUInteger row = [indexPath row];
      NSString *rowString = [recipesNames objectAtIndex:row];
      cell.textLabel.text = rowString;
      cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
      [rowString release];
  
      return cell;
  }
  
  
  
  #pragma mark -
  #pragma mark Table view delegate methods
  
  - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
  
      if (childController == nil) {
          childController = [[DisclosureDetailController alloc] initWithNibName:@"DisclosureDetail" bundle:nil];
      }
  
      childController.title = @"Dettagli";
      NSUInteger row = [indexPath row];
  
      childController.recipeName = [recipesNames objectAtIndex:row];
  
      NSArray *recipeRawArray = [recipesArray objectForKey:childController.recipeName];
      childController.recipeLink = [recipeRawArray objectAtIndex:kRecipeArrayLink];
      childController.recipeDifficulty = [recipeRawArray objectAtIndex:kRecipeArrayDifficulty];
  
      [self.navigationController pushViewController:childController animated:YES];
  }
  
  
  
  @end
  </code></pre>
  
  <p>This is the crash log</p>
  
  <pre><code>Program received signal:  “EXC_BAD_ACCESS”.
  (gdb) bt
  #0  0x00f0da63 in objc_msgSend ()
  #1  0x04b27ca0 in ?? ()
  #2  0x00002665 in -[RecipesListController viewWillAppear:] (self=0x4b38a00, _cmd=0x6d81a2, animated=1 '\001') at /Users/claudiocanino/Documents/iOS/CottoMangiato/Classes/RecipesListController.m:67
  #3  0x00370c9a in -[UINavigationController _startTransition:fromViewController:toViewController:] ()
  #4  0x0036b606 in -[UINavigationController _startDeferredTransitionIfNeeded] ()
  #5  0x0037283e in -[UINavigationController pushViewController:transition:forceImmediate:] ()
  #6  0x04f49549 in -[UINavigationControllerAccessibility(SafeCategory) pushViewController:transition:forceImmediate:] ()
  #7  0x0036b4a0 in -[UINavigationController pushViewController:animated:] ()
  #8  0x00003919 in -[CategoryViewController tableView:didSelectRowAtIndexPath:] (self=0x4b27ca0, _cmd=0x6d19e3, tableView=0x500c200, indexPath=0x4b2d650) at /Users/claudiocanino/Documents/iOS/CottoMangiato/Classes/CategoryViewCotroller.m:104
  #9  0x0032a794 in -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:] ()
  #10 0x00320d50 in -[UITableView _userSelectRowAtPendingSelectionIndexPath:] ()
  #11 0x000337f6 in __NSFireDelayedPerform ()
  #12 0x00d8cfe3 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ ()
  #13 0x00d8e594 in __CFRunLoopDoTimer ()
  #14 0x00ceacc9 in __CFRunLoopRun ()
  #15 0x00cea240 in CFRunLoopRunSpecific ()
  #16 0x00cea161 in CFRunLoopRunInMode ()
  #17 0x016e0268 in GSEventRunModal ()
  #18 0x016e032d in GSEventRun ()
  #19 0x002c342e in UIApplicationMain ()
  #20 0x00001c08 in main (argc=1, argv=0xbfffef58) at /Users/claudiocanino/Documents/iOS/CottoMangiato/main.m:15
  </code></pre>
  
  <p>Another bt log:</p>
  
  <pre><code>(gdb) bt
  #0  0x00cd76a1 in __CFBasicHashDeallocate ()
  #1  0x00cc2bcb in _CFRelease ()
  #2  0x00002dd6 in -[RecipesListController setRecipesArray:] (self=0x6834d50, _cmd=0x4293, _value=0x4e3bc70) at /Users/claudiocanino/Documents/iOS/CottoMangiato/Classes/RecipesListController.m:16
  #3  0x00002665 in -[RecipesListController viewWillAppear:] (self=0x6834d50, _cmd=0x6d81a2, animated=1 '\001') at /Users/claudiocanino/Documents/iOS/CottoMangiato/Classes/RecipesListController.m:67
  #4  0x00370c9a in -[UINavigationController _startTransition:fromViewController:toViewController:] ()
  #5  0x0036b606 in -[UINavigationController _startDeferredTransitionIfNeeded] ()
  #6  0x0037283e in -[UINavigationController pushViewController:transition:forceImmediate:] ()
  #7  0x091ac549 in -[UINavigationControllerAccessibility(SafeCategory) pushViewController:transition:forceImmediate:] ()
  #8  0x0036b4a0 in -[UINavigationController pushViewController:animated:] ()
  #9  0x00003919 in -[CategoryViewController tableView:didSelectRowAtIndexPath:] (self=0x4b12970, _cmd=0x6d19e3, tableView=0x5014400, indexPath=0x4b2bd00) at /Users/claudiocanino/Documents/iOS/CottoMangiato/Classes/CategoryViewCotroller.m:104
  #10 0x0032a794 in -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:] ()
  #11 0x00320d50 in -[UITableView _userSelectRowAtPendingSelectionIndexPath:] ()
  #12 0x000337f6 in __NSFireDelayedPerform ()
  #13 0x00d8cfe3 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ ()
  #14 0x00d8e594 in __CFRunLoopDoTimer ()
  #15 0x00ceacc9 in __CFRunLoopRun ()
  #16 0x00cea240 in CFRunLoopRunSpecific ()
  #17 0x00cea161 in CFRunLoopRunInMode ()
  #18 0x016e0268 in GSEventRunModal ()
  #19 0x016e032d in GSEventRun ()
  #20 0x002c342e in UIApplicationMain ()
  #21 0x00001c08 in main (argc=1, argv=0xbfffef58) at /Users/claudiocanino/Documents/iOS/CottoMangiato/main.m:15
  </code></pre>
  
  <p>Thanks</p>