objective-c threading with NSobject subclass - objective-c

Im using a threading class (.h/.m below) where the subclass is UIViewcontroller works without any issues.
#interface myFirstClass : UIViewController <MyOperationDelegate>{
However when I use it where the subclass is a NSobject to call a reachability class checking for internet connection, the App crashes when calling performSelectorOnMainThread? I dont understand why, there are no error when I build the App and when it crashes all i get is EXC_BAS_ACCESS. Is it not possible to do this when dealing with an NSObject? Any suggestion will be helpful for me.
#interface AppController : NSObject <MyOperationDelegate>{
myThreading.h
#protocol MyOperationDelegate
#required
-(void) updatedStatus:(NSArray*)items;
-(void) failedStatusWithError:(NSError*)error;
#end
#interface MyOperation : NSObject {
NSObject<MyOperationDelegate> * delegate;
NSOperationQueue *queue;
}
#property (retain) NSObject<MyOperationDelegate> *delegate;
-(void)load: (NSString *)stringUrlPath:(NSString *)functionAction;
#end
myThreading.m
#interface MyOperation (NSObject)
-(void)dispatchLoadingOperation:(NSDictionary *)aParameters;
#end
#implementation MyOperation
#synthesize delegate;
-(id)init
{
if ([super init]!=nil) {
queue = [NSOperationQueue new];
[queue setMaxConcurrentOperationCount:1];
}
return self;
}
-(void)load: (NSString *)stringUrlPath: (NSString *)functionAction {
[self dispatchLoadingOperation:[NSDictionary dictionaryWithObjectsAndKeys:
stringUrlPath, #"urlString", functionAction, #"action", nil]];
}
-(void)dealloc {
[queue cancelAllOperations];
self.delegate = nil;
[super dealloc];
}
-(void)dispatchLoadingOperation:(NSDictionary *)aParameters {
if([aParameters objectForKey:#"action"] == #"getStatus"){
#synchronized(self) {
NSInvocationOperation *operation = [[NSInvocationOperation alloc] initWithTarget:self
selector:#selector(fetchCheckStatus:)
object:aParameters];
[queue addOperation:operation];
[operation release];
}
}
}
-(void) fetchCheckStatus:(NSDictionary *)aParameters
{
NSData* data = [[NSMutableData alloc] initWithContentsOfURL:[NSURL URLWithString:[aParameters objectForKey:#"urlString"]] ];
NSError *error;
NSString *responseString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
if (responseString != nil) {
NSMutableArray *rssItems;
[self.delegate performSelectorOnMainThread:#selector(updatedStatus:) withObject:[NSArray arrayWithObjects:rssItems, nil] waitUntilDone:NO];
} else {
[queue cancelAllOperations];
[self.delegate performSelectorOnMainThread:#selector(failedStatusWithError:) withObject:error waitUntilDone:NO];
}
[responseString autorelease];
[data release];
}
#end

The problem are these lines:
NSMutableArray *rssItems;
[self.delegate performSelectorOnMainThread:#selector(updatedStatus:) withObject:[NSArray arrayWithObjects:rssItems, nil] waitUntilDone:NO];
You declare a variable rssItems but don't set it. It will contain random garbage from the stack which will then be interpreted as a pointer. Maybe sometimes you're lucky and the value is actually a pointer to a living object, but more likely dereferencing it causes your crash.
You need to actually initialize the variable, e.g.:
NSMutableArray *rssItems = nil;
but I guess you really want:
NSMutableArray *rssItems = [NSMutableArray array];

Related

cocoa - unarchivedObjectOfClass does not call initWithCoder

I am developing a macOS app using objective-C.
I tried to save a NSArray object in Core Data. I write
- (id)reverseTransformedValue:(id)value
{
return [NSKeyedUnarchiver unarchivedObjectOfClass:[NSArray class] fromData:value error:nil];
}
in the class that inherits NSValueTransformer.
And one of elements in my NSArray object is not of primary kind(which has properties called courseName and courseInfos), so I conform in this element's class. In this class ,I write:
- (id)initWithCoder:(NSCoder *)aDecoder
{
self = [[self class] new];
if (self = [super init])
{
self.courseName = [aDecoder decodeObjectForKey:#"courseName"];
self.courseInfos = [aDecoder decodeObjectForKey:#"courseInfos"];
}
return self;
}
When my apps runs, the reverseTransformedValue: method is called, and all elements but that special nonprimary element in my NSArray object are decoded. I put a breakpoint in the initWithCoder: method in that special element's class, and it never runs. I use some tools and find that element is successfully stored in my core data, so its encoding process has no problem.
I Fixed it, here is the solution:
My object is 'Address' (note: it is not NSArray)
Address.h
#interface Address : NSObject <NSSecureCoding>
#property (nonatomic, strong) NSString *street;
#property (nonatomic, strong) NSString *city;
#end
Address.m
#implementation Address
- (id) initWithCoder:(NSCoder *)aDecoder
{
self = [self init];
if (self == nil)
{
return nil;
}
self.street = [aDecoder decodeObjectOfClass:[Address class] forKey:#"street"];
self.city = [aDecoder decodeObjectOfClass:[Address class]
forKey:#"city"];
return self;
}
- (void)encodeWithCoder:(NSCoder *)encoder
{
[encoder encodeObject:self.street forKey:#"street"];
[encoder encodeObject:self.city forKey:#"city"];
}
+ (BOOL)supportsSecureCoding
{
return YES;
}
Archive.h
#property (nonatomic, strong) Address *address;
Archive.m
UserDBO *userDBO = [[UserDBO alloc] init];
// Archive
NSError *error = nil;
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:self.address requiringSecureCoding:YES error:&error];
if(error)
{
NSLog(#"archivedDataWithRootObject: %#", error);
}
userDBO.address = data;
// UnArchive
Address *address = [NSKeyedUnarchiver unarchivedObjectOfClass:[Address class] fromData:userDBO.address error:&error];
if(error)
{
NSLog(#"unarchivedObjectOfClass: %#", error);
}
UserDBO.h
#property (nonatomic, strong) NSData *address;

Saving the title of a button so it can be accessed in another view (Objective-C)

I'm trying to save the name of a button using a singleton so that the name can be accessed in another view to play a video with the same name. However, I'm getting the error: SIGABRT. I don't really see what's wrong with my code. Any ideas?
#import "List.h"
#import "MyManager.h"
#import "Video.h"
#implementation ExerciseList
-(IBAction) goToVideo:(UIButton *) sender{
MyManager *sharedManager = [MyManager sharedManager];
sharedManager.vidName = [[sender titleLabel] text];
Video *videoGo = [[Video alloc] initWithNibName: #"Video" bundle: nil];
[self.navigationController pushViewController: videoGo animated: YES];
[videoGo release];
}
Here is my .h and .m for MyManager:
#import <foundation/Foundation.h>
#interface MyManager : NSObject {
NSMutableArray *workouts;
NSString *vidName;
}
#property (nonatomic, retain) NSMutableArray *workouts;
#property (nonatomic, retain) NSString *vidName;
+ (id)sharedManager;
#end
#import "MyManager.h"
static MyManager *sharedMyManager = nil;
#implementation MyManager
#synthesize workouts;
#synthesize vidName;
#pragma mark Singleton Methods
+ (id)sharedManager {
#synchronized(self) {
if (sharedMyManager == nil)
sharedMyManager = [[self alloc] init];
}
return sharedMyManager;
}
- (id)init {
if ((self = [super init])) {
workouts = [[NSMutableArray alloc] init];
vidName = [[NSString alloc] init];
}
return self;
}
-(void) dealloc{
self.workouts = nil;
self.vidName = nil;
[super dealloc];
}
#end
You should access the title of the button
sharedManger.vidName = [sender currentTitle];
However you are not using ARC so also check where your vidName property is retain or copy.
if it is not retain or copy then you can use this code also
if(sharedManger.vidname != nil){
[sharedManger.vidName release];
sharedManger.vidName = nil;
}
sharedManger.vidName = [[sender currentTitle] retain];

NSKeyedArchiver archivedDataWithRootObject: does not call encodeWithCoder

I cant get the archivedDataWithRootObject method to call encodeWithCoder, it seems pretty simple from what I understand but it doesn't work.
Here's the code:
#import <Foundation/Foundation.h>
#interface Details : NSObject <NSCoding>{
NSMutableArray *myArray;
}
#property(nonatomic,retain) NSMutableArray *myArray;
#end
#import "Details.h"
#implementation Details
#synthesize myArray;
-(id)init{
[super init];
return self;
}
-(id)initWithCoder:(NSCoder *)aDecoder{
NSLog(#"initWithCoder");
if (self = [super init])
{
self.myArray = [[aDecoder decodeObjectForKey:#"details"]retain];
}
return self;
}
- (NSMutableArray*)getDetails{
NSLog(#"getDetials");
// NSUserDefaults *currentDefaults = [NSUserDefaults standardUserDefaults];
NSData *details = [[NSUserDefaults standardUserDefaults] objectForKey:#"details"];
if (details != nil){
NSArray *oldSavedArray = [NSKeyedUnarchiver unarchiveObjectWithData:details];
if (oldSavedArray != nil)
self.myArray = [[NSMutableArray alloc] initWithArray:oldSavedArray];
else
self.myArray = [[NSMutableArray alloc] initWithCapacity:1];
}
return self.myArray;
}
- (void) addDetails:(NSMutableArray *)details{
NSLog(#"add Details");
[self.myArray addObject:details];
[NSKeyedArchiver archivedDataWithRootObject:self.myArray];
}
- (void) encodeWithCoder:(NSCoder *)coder;
{
NSLog(#"encodeWithCoder");
[coder encodeObject:self.myArray forKey:#"details"];
}
#end
NSLog(#"encodeWithCoder") doesn't run.
I might be missing something, If anyone has any ideas it would be appreciated.
[NSKeyedArchiver archivedDataWithRootObject:self.myArray];
You are telling the NSKeyedArchiver to archive the myArray variable, not the object you have just implemented <NSCoding> with!
Also that method returns NSData * which you then have to write to disk separately if needed.
Try this:
NSData * archivedData = [NSKeyedArchiver archivedDataWithRootObject:self];

Parameters to thread Objective-C

Trying to use class variables in thread and getting EXC_BAS_ACCESS.
Code snippet:
#interface ViewController : UIViewController {
NSString* accountLoginName;
NSString* accountPassword;
}
in implementation:
accountLoginName = [NSString stringWithString:textFieldLoginName.text];
accountPassword = [NSString stringWithString:textFieldPassword.text];
[self performSelectorInBackground:#selector(loginAtBackgroundSelector:) withObject:nil];
-(void)loginAtBackgroundSelector:(UIAlertView*)alert
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
NSLog(#"%#\n%#", accountLoginName, accountPassword);
[self login];
[self dismissAlert:alert];
[pool release];
}
just trying to write to console and getting error in this part of code, but error in the loginAtBackgroundSelector appears from time to time.
-(AlertType)login
{
NSLog(#"%#\n%#", accountLoginName, accountPassword);
}
Try this in interface:
#interface ViewController : UIViewController {
NSString* accountLoginName;
NSString* accountPassword;
}
#property(nonatomic, retain) NSString* accountLoginName;
#property(nonatomic, retain) NSString* accountPassword;
And this in the implementation (in the place where you assign the values):
self.accountLoginName = [NSString stringWithString:textFieldLoginName.text];
self.accountPassword = [NSString stringWithString:textFieldPassword.text];
[self performSelectorInBackground:#selector(loginAtBackgroundSelector:) withObject:nil];
Additionaly in the dealloc:
-(void)dealloc {
[accountLoginName release];
[accountPassword release];
[super dealloc];
}
Let me know if it helps.

Leak on iPad that I don't understand

I've got a leak in my application and I do not know why. Maybe I've got all memory managment thing wrong. In my code I've got UIViewController object which have ivar TelephoneValidator *validator
TelephoneValidator is TelephoneValidator : NSObject
So in my initialization function of UIViewController object (initWithFieldData) I've got:
-(id) initWithFieldData: (NSMutableDictionary*) fieldData
{
...
validatorOptions = [fieldData objectForKey:#"fieldValidator"];
...
}
Now in my viewDidLoad I've got:
- (void)viewDidLoad {
...
if (![validatorOptions respondsToSelector:#selector(isEqualToString:)]) {
validator = [[TelephoneValidator alloc] initWithOptions: validatorOptions];
}
else {
validator = nil;
}
...
}
Basicly if my validatorOptions isn't NSString the validator ivar became TelephoneValidator instance.
In my dealloc:
- (void)dealloc {
if(validator != nil)
{
[validator release];
validator = nil;
}
...
[super dealloc];
}
I've checked a couple of times if dealloc works, and it is. After calling dealloc the validator is released (calling any method on validator after [validator release] gets me exception).
And yet in Instruments it is telling me that TelephoneValidator is leaked. And after double clicking in Instruments the line of code that is highlited is:
validator = [[TelephoneValidator alloc] initWithOptions: validatorOptions];
What am I doing wrong?
UPDATE:
Here is my header information of UIViewController:
#interface GenericViewController : UIViewController <UITextFieldDelegate>{
UIImage *backgroundImage;
NSString *step; // na ktorym kroku jestesmy
id <GenericControllerDelegate> delegate; //delegata z ktorej bedziemy pobierali dane
UITextField *textField;
NSString *fieldName; //nazwa pola (potrzebujemy zeby zapisac do modelu odpowiedni tekst
UILabel *textLabel;
UILabel *stepsLabel;
UILabel *prefixTextLabel;
NSString *fieldPlaceholder;
NSString *textLabelText;
NSString *textLabelTextPl; //w jezyku polskim
NSString *prefixTextLabelText; //w jezyku eng
NSString *prefixTextLabelTextPl; //w jezyku polskim prefix
NSString *fieldRequired;
NSString *keyboardType;
NSString *capitalizeType;
UIButton *button; //forward button
UIButton *button2; //backward button
//to bedzie do przerobienia bo bedziemy mieli tablicje walidatorow a nie jeden walidator
NSString *validatorType;
//maksymalna dlugosc pola
int maxLengthOfTextField;
NSArray* validatorOptions;
TelephoneValidator *validator;
//patientModel
PatientData *patientModel;
}
TelephoneValidator header:
#import <Foundation/Foundation.h>
#import "MAOTranslate.h"
#interface TelephoneValidator : NSObject {
//opcje walidacyjne
NSString *phonePrefix;
NSString *phonePostfix;
int phoneLength;
NSString *message;
NSString *messagePl;
UIAlertView *alertView;
}
-(id) initWithOptions:(NSArray *) optionsArray;
-(void) displayMessage;
-(BOOL) validate: (NSString *) phoneNumber;
#end
TelephoneValidator class:
#import "TelephoneValidator.h"
#implementation TelephoneValidator
//#synthesize phoneNumber;
-(id) initWithOptions:(NSArray *) optionsArray;
{
if(self = [[TelephoneValidator alloc] init])
{
phonePrefix = [optionsArray objectAtIndex:0];
phonePostfix = [optionsArray objectAtIndex:1];
phoneLength = [[optionsArray objectAtIndex:2] intValue];
message = [optionsArray objectAtIndex:3];
messagePl = [optionsArray objectAtIndex:4];
}
else {
self = nil;
}
return self;
}
//wyswietlamy wiadomosc
-(void) displayMessage
{
NSString *displayMsg;
if ([[MAOTranslate getLanguage] isEqualToString:#"pl"]) {
displayMsg = messagePl;
}
else {
displayMsg = message;
}
alertView = [[UIAlertView alloc] initWithTitle:#"Alert" message:displayMsg delegate:self cancelButtonTitle:#"ok" otherButtonTitles:nil];
[alertView show];
}
-(BOOL) validate: (NSString *) phoneNumber
{
//dlugosc
if ([phoneNumber length] != phoneLength) {
NSLog(#"zla dlugosc");
return NO;
}
NSLog(#"tutaj");
//sprawdzamy prefix
if ([phonePrefix length]!= 0) {
NSLog(#"w srodku ifa");
if ([phoneNumber compare:phonePrefix options:NSLiteralSearch range:NSMakeRange(0, [phonePrefix length])] != 0) {
NSLog(#"zly prefix");
[self displayMessage];
return NO;
}
}
//sprawdzamy postfix
if([phonePostfix length] != 0)
{
if ([phoneNumber compare:phonePostfix options:NSLiteralSearch range:NSMakeRange([phoneNumber length]-[phonePostfix length], [phonePostfix length])] != 0) {
NSLog(#"zly postfix");
[self displayMessage];
return NO;
}
}
//sprawdzamy czy string jest numeryczny
NSCharacterSet *alphaNums = [NSCharacterSet decimalDigitCharacterSet];
NSCharacterSet *inStringSet = [NSCharacterSet characterSetWithCharactersInString:phoneNumber];
if (![alphaNums isSupersetOfSet:inStringSet])
{
NSLog(#"zly format ");
[self displayMessage];
return NO;
}
return YES; //zwalidowany poprawnie
}
-(void) dealloc
{
[alertView release];
alertView = nil;
[super dealloc];
}
You need to call [super dealloc] at the end of the dealloc method.
See These both lines
validator = [[TelephoneValidator alloc] initWithOptions: validatorOptions];
and inside initWithOptions
if(self = [[TelephoneValidator alloc] init])
You are allocing twice the validator, so there is a leak.
Could it be that instruments is pointing to validatorOptions as the source of the leak? Is it a retained property being released at dealloc or not? I can't say for sure, the code you posted is not enough to arrive to a conclusion.
Also, as willcodejavaforfood says, you must always call [super dealloc]; at the end of your dealloc method. No code must come after it.
Edit:
I'm back. But Bruno Domingues got it right already, you are allocating twice, in which case, the first one leaks. You should change your -initWithOptions: code to:
-(id) initWithOptions:(NSArray *) optionsArray;
{
if((self = [super init])){
// ... rest of code is fine
}
return self;
}