Problems trying to override methods in Objective-C (iPhone) - iphone

Question

this my problem i have a class X that inherits UITableViewController class and a class Y that inherits the X class, when i try to override a method in the Y class the method in the X class is invoked... and i can't find references to understand what's happening... can anyone help me?
Thanks in advance!
Code!
mluListBuilder.h
#import <UIKit/UIKit.h>
#interface mluListBuilder : UITableViewController {
NSString *sListTitle;
NSString *sEntityName;
NSArray *aEntityProperties;
NSMutableArray *maListRecords;
NSManagedObjectContext *mocList;
NSFetchRequest *frListRecords;
NSEntityDescription *edListRecords;
NSArray *aOrderByProperties;
NSArray *aToolBarItems;
NSArray *aToolBarItemsActions;
}
#property (nonatomic, retain) NSString *sListTitle;
#property (nonatomic, retain) NSString *sEntityName;
#property (nonatomic, retain) NSArray *aEntityProperties;
#property (nonatomic, retain) NSMutableArray *maListRecords;
#property (nonatomic, retain) NSManagedObjectContext *mocList;
#property (nonatomic, retain) NSFetchRequest *frListRecords;
#property (nonatomic, retain) NSEntityDescription *edListRecords;
#property (nonatomic, retain) NSArray *aOrderByProperties;
#property (nonatomic, retain) NSArray *aToolBarItems;
#property (nonatomic, retain) NSArray *aToolBarItemsActions;
- (id) initWithStyle: (UITableViewStyle) style
listTitle: (NSString *) psListTitle
entityName: (NSString *) psEntityName
entityProperties: (NSArray *) paEntityProperties
orderListByProperties: (NSArray *) paOrderByProperties
toolBarItems: (NSArray *) paToolBarItems
toolBarItemsActions: (NSArray *) paToolBarItemsActions;
- (void)newRecord;
- (void)deleteRecord;
#end
mluListBuilder.m
#import "mluListBuilder.h"
#implementation mluListBuilder
#synthesize sListTitle,
sEntityName,
aEntityProperties,
maListRecords,
mocList,
frListRecords,
edListRecords,
aOrderByProperties,
aToolBarItems,
aToolBarItemsActions;
- (id) initWithStyle: (UITableViewStyle) style
listTitle: (NSString *) psListTitle
entityName: (NSString *) psEntityName
entityProperties: (NSArray *) paEntityProperties
orderListByProperties: (NSArray *) paOrderByProperties
toolBarItems: (NSArray *) paToolBarItems
toolBarItemsActions: (NSArray *) paToolBarItemsActions
{
sListTitle = psListTitle;
sEntityName = psEntityName;
aEntityProperties = paEntityProperties;
aOrderByProperties = paOrderByProperties;
aToolBarItems = paToolBarItems;
aToolBarItemsActions = paToolBarItemsActions;
if (self = [super initWithStyle:style]) {
}
return self;
}
- (void)viewDidLoad {
self.title = NSLocalizedString(sListTitle, nil);
if ([aToolBarItems count] > 0) {
NSMutableArray *maToolBarItems = [[NSMutableArray alloc] init];
self.navigationController.toolbarHidden = NO;
for (int i = 0; i < [aToolBarItems count]; i++) {
UIBarButtonItem * bbiToolBarItem = [[UIBarButtonItem alloc]
initWithTitle:NSLocalizedString([aToolBarItems objectAtIndex:i], nil)
style:UIBarButtonItemStyleBordered
target:self
action:NSSelectorFromString([aToolBarItemsActions objectAtIndex:i])
];
[maToolBarItems addObject:bbiToolBarItem];
}
self.toolbarItems = maToolBarItems;
} else {
self.navigationController.toolbarHidden = YES;
}
if (mocList != nil) {
frListRecords = [[NSFetchRequest alloc] init];
NSSortDescriptor *sdListRecords = [[NSSortDescriptor alloc] initWithKey:#"name" ascending:YES];
[frListRecords setSortDescriptors:[[NSArray alloc] initWithObjects:sdListRecords, nil]];
edListRecords = [NSEntityDescription entityForName:sEntityName inManagedObjectContext:mocList];
[frListRecords setEntity:edListRecords];
NSError *errFetchRequest;
maListRecords = [[mocList executeFetchRequest:frListRecords error:&errFetchRequest] mutableCopy];
}
[super viewDidLoad];
}
- (void)viewWillAppear:(BOOL)animated {
NSError *errFetchRequest;
maListRecords = [[mocList executeFetchRequest:frListRecords error:&errFetchRequest] mutableCopy];
[self.tableView reloadData];
if (self.navigationController.toolbarHidden == YES) {
if ([aToolBarItems count] > 0) {
self.navigationController.toolbarHidden = NO;
}
}
}
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
#pragma mark Table view methods
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
// Customize the number of rows in the table view.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [maListRecords count];
}
// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
for (UIView *vwExisting in cell.contentView.subviews) {
[vwExisting removeFromSuperview];
}
NSEntityDescription *edCurrentRecord = [maListRecords objectAtIndex:indexPath.row];
UILabel *lblCell = [[UILabel alloc] initWithFrame:CGRectMake(5.0, 5.0, 280, 20.0)];
[lblCell setText:edCurrentRecord.name];
[cell.contentView addSubview:lblCell];
[cell setSelectionStyle:UITableViewCellSelectionStyleNone];
return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
// Navigation logic may go here. Create and push another view controller.
// AnotherViewController *anotherViewController = [[AnotherViewController alloc] initWithNibName:#"AnotherView" bundle:nil];
// [self.navigationController pushViewController:anotherViewController];
// [anotherViewController release];
}
- (void)dealloc {
[super dealloc];
}
- (void)newRecord {
NSLog(#"%#", [self class]);
}
- (void)deleteRecord {
}
#end
mluLawyerCaseSituationsList.h
#import <Foundation/Foundation.h>
#import "mluListBuilder.h";
#interface mluLawyerCaseSituationsList : mluListBuilder {
}
- (void)newRecord;
#end
mluLawyerCaseSituationsList.m
#import "mluLawyerCaseSituationsList.h"
#implementation mluLawyerCaseSituationsList
- (void)newRecord {
NSLog(#"%#", [self class]);
}
#end
Calling the mluLawyerCaseSituationsList
mluLawyerCaseSituationsList *vcCaseSituations = [[mluListBuilder alloc]
initWithStyle:UITableViewStylePlain
listTitle:#"titCaseSituations"
entityName:#"case_situations"
entityProperties:[[NSArray alloc] initWithObjects:#"name", nil]
orderListByProperties:[[NSArray alloc] initWithObjects:#"name", nil]
toolBarItems:[[NSArray alloc] initWithObjects:#"btNew", nil]
toolBarItemsActions:[[NSArray alloc] initWithObjects:#"newRecord", nil]
];
Output... :(
2009-12-17 17:30:02.726 mluLawyer[2862:20b] mluListBuilder
Hope it helps...

Answer 1

I’ve been looking through your code only briefly, but it seems obvious (from code and from the output) that you allocate an instance of class X (mluListBuilder).
Of course, you cannot expect to have a method of class Y (mluLawyerCaseSituationsList), performed when Y is derived from X and the object is of class X.

Answer 2

So, you have:
#interface X : UITableViewController
- (void) method;
#end
#interface Y : X
- (void) method;
#end
You are calling -method, but it is being invoked on X, not Y? Only way that can happen is if you have an instance of X instead of Y (or if someone is playing very silly buggers with the runtime -- unlikely).
Add NSLog(#"%#", [self class]); to the method implementations and see what the class of the instance really is!

Answer 3

You don't give us much information in your question, but the following is how it should work:
Class_X.h:
#interface Class_X : UITableViewController
{
}
- (void)someMethod;
#end
Class_X.m:
#import "Class_X.h"
#implementation Class_X
- (void)someMethod
{
NSLog(#"method in Class_X was called");
}
#end
Class_Y.h:
#import "Class_X.h"
#interface Class_Y : Class_X
{
}
- (void)someMethod;
#end
Class_Y.m:
#import "Class_Y.h"
#implementation Class_Y
- (void)someMethod
{
NSLog(#"method in Class_Y was called");
}
#end
Elsewhere:
#import "Class_Y.h"
...
Class_X * x_instance = [[Class_X alloc] init];
Class_Y * y_instance = [[Class_Y alloc] init];
[x_instance someMethod];
[y_instance someMethod];
[Class_Y release];
[Class_X release];
Output:
method in Class_X was called
method in Class_Y was called