I get an error when running my code. The culprit is me accessing a string from a plist below:
NSString *sImageFile = [dictionary objectForKey:#"answerCorrect"];
NSLog(#"%#",sImageFile);
I have this in my cocos2d Init shown here:
-(id) init
{
// always call "super" init
// Apple recommends to re-assign "self" with the "super" return value
if( (self=[super init])) {
NSUserDefaults *sud = [NSUserDefaults standardUserDefaults];
NSString *ctlLang = [sud valueForKey:#"ctlLang"];
NSNumber *questionState = [sud valueForKey:#"questionState"];
NSNumber *scoreState = [sud valueForKey:#"scoreState"];
gameArray = (NSMutableArray *)[sud valueForKey:#"gameArray"];
for (NSString *element in gameArray) {
NSLog(#"\nQL gameArray value=%d\n", [element intValue]);
}
NSString *path = [[NSBundle mainBundle] bundlePath];
NSString *finalPath = [path stringByAppendingPathComponent:ctlLang];
dictionary = [NSDictionary dictionaryWithContentsOfFile:finalPath];
NSString *sImageFile = [dictionary objectForKey:#"answerCorrect"];
NSLog(#"%#",sImageFile);
}
}
The printing of the string works fine in the init section of the scene. The problem occurs in a method I define later. For some reason it is not returning the string in the method shown here:
-(void) checkAnswer: (id) sender {
CGSize size = [[CCDirector sharedDirector] winSize];
CCMenuItemSprite *sAnswer = (CCMenuItemSprite *)sender;
NSLog(#"Checking Answer Tag is ---> %d",sAnswer.tag);
NSString *sImageFile = [dictionary objectForKey:#"answerCorrect"];
NSLog(#"%#",sImageFile);
if ([question.answer integerValue] == sAnswer.tag) {
//...
}
}
What am I missing here? the program bombs at the NSLog statement.
You assign the object returned by dictionaryWithContentsOfFile: to the dictionary ivar but you do not claim ownership of it by sending it a retain message to it:
dictionary = [NSDictionary dictionaryWithContentsOfFile:finalPath];
The method dictionaryWithContentsOfFile: returns an object you do not own. Probably, by the time checkAnswer: is executed the object has already been deallocated. You need to retain it:
dictionary = [[NSDictionary dictionaryWithContentsOfFile:finalPath] retain];
Or use alloc-initWithContentsOfFile: instead, which returns an object you own:
dictionary = [[NSDictionary alloc] initWithContentsOfFile:finalPath];
And the same goes for the gameplay ivar. You do not own the object returned by valueForKey: and you need to retain it. So this line:
gameArray = (NSMutableArray *)[sud valueForKey:#"gameArray"];
should be:
gameArray = [[sud valueForKey:#"gameArray"] retain];
I don't think you are retaining the autoreleased dictionary created in your init method. You set the dictionary ivar but don't retain it. When you access it later, it is likely not valid anymore
Related
As I have a requirement to add similar objects into the array, I have created new dictionary in such a way.
NSMutableDictionary* existingStepDict = [[[arrayForSteps objectAtIndex:0] mutableCopy] autorelease];
[arrayForSteps addObject:existingStepDict];
[existingStepDict release];
Now, what happens here is that later when I change something in any one of the dictionary, the other one also gets updated. I require both these dictionaries to behave independently.
For that I went through Deep-copy of dictionaries whose code is like this.
NSMutableDictionary* existingStepDict = [[[arrayForSteps objectAtIndex:0] mutableCopy] autorelease];
NSMutableDictionary* destination = [NSMutableDictionary dictionaryWithCapacity:0];
NSDictionary *deepCopy = [[NSDictionary alloc] initWithDictionary:existingStepDict copyItems: YES];
if (deepCopy) {
[destination addEntriesFromDictionary: deepCopy];
[deepCopy release];
}
//add Properties array to Steps Dictionary
[arrayForSteps addObject:destination];
But this too didn't reflect the difference. I know I am making some minor mistake here.
But could some one help me getting my result?
Thanks a lot!
There's an easy way to get a full deepcopy of an NSDictionary o NSArray using the NSCoding (serialization) protocol.
- (id) deepCopy:(id)mutableObject
{
NSData *buffer = [NSKeyedArchiver archivedDataWithRootObject:mutableObject];
return [NSKeyedUnarchiver unarchiveObjectWithData: buffer];
}
In this way you can duplicate any object plus all the obects it contains in a single step.
when I need a mutable deep copy of a NSDictionary I create a Category with this method:
- (NSMutableDictionary *)mutableDeepCopy
{
NSMutableDictionary *returnDict = [[NSMutableDictionary alloc] initWithCapacity:[self count]];
NSArray *keys = [self allKeys];
for (id key in keys) {
id oneValue = [self valueForKey:key];
id oneCopy = nil;
if ([oneValue respondsToSelector:#selector(mutableDeepCopy)]) {
oneCopy = [oneValue mutableDeepCopy];
} else if ([oneValue respondsToSelector:#selector(mutableCopy)]) {
oneCopy = [oneValue mutableCopy];
}
if (oneCopy == nil) {
oneCopy = [oneValue copy];
}
[returnDict setValue:oneCopy forKey:key];
}
return returnDict;
}
EDIT
and searching the web I found this, I haven't tested
NSMutableDictionary *mutableCopy = (NSMutableDictionary *)CFPropertyListCreateDeepCopy(kCFAllocatorDefault, (CFDictionaryRef)originalDictionary, kCFPropertyListMutableContainers);
I'm trying to create an NSDictionary full of arrays in the implementation file of my model but my code hasn't worked yet. I want to create arrays that are lists of types of dogs and cats and then add those arrays to a dictionary with keys called DOG and CAT. Here is my code:
#implementation wordDictionary
#synthesize catList = _catList;
#synthesize dogList = _dogList;
#synthesize standardDictionary =_standardDictionary;
- (void)setCatList:(NSMutableArray *)catList
{
self.catList = [NSMutableArray arrayWithObjects:#"lion", #"puma", #"snow leopard", nil];
}
- (void)setDogList:(NSMutableArray *)dogList
{
self.dogList = [NSMutableArray arrayWithObjects:#"pit bull", #"pug", #"chihuahua", nil];
}
-(void)setStandardDictionary:(NSMutableDictionary *)standardDictionary
{
[self.standardDictionary setObject: _catList forKey:#"CAT"];
[self.standardDictionary setObject: _dogList forKey:#"DOG"];
}
- (NSString*)selectKey
{
NSInteger keyCount = [[self.standardDictionary allKeys] count];
NSInteger randomKeyIndex = arc4random() % keyCount;
NSString *randomKey = [[self.standardDictionary allKeys] objectAtIndex:randomKeyIndex];
return randomKey;
}
#end
This code is the model. The model is hooked up to my view controller such that when a user taps a button, the NSString returned from randomKey is displayed in a label on the screen. So the text will read either CAT or DOG. Here's the code for that:
- (IBAction)changeGreeting:(UIButton*)sender {
NSString *chosenKey = [self.dictionary selectKey];
NSString *labelText = [[NSString alloc] initWithFormat:#"%#", chosenKey];
self.label.text = labelText;
}
Unfortunately when I tap the button on the simulator I get an error message saying: Thread 1:EXC_ARITHMETIC (code=EXC_1386_DIV, subcode=0x0) at NSInteger randomKeyIndex = arc4random() % keyCount; and it appears that I'm getting it because neither my NSArray nor my NSDictionary have any objects inside of them.
Does anyone have any idea why my NSArray and NSDictionary haven't been populated?
Thanks very much.
The simple answer is that there isn't any code here that calls the methods to set the arrays or dictionary.
But the real underlying issue is that there are a couple of bad 'patterns' going on here that you should fix:
In your setter methods (setCatList:, setDogList:, setStandardDictionary:) you're not setting the properties in question to the values that are passed in. For example, you should be setting catList to the passed in "catList" variable.
- (void)setCatList:(NSMutableArray *)catList
{
if (_catList != catList) {
[_catList release];
_catList = [catList retain];
}
}
Then you should have some kind of "setup" happening, usually in a method in the view controller like viewDidLoad:
[wordDictionary setCatList:[NSMutableArray arrayWithObjects:#"lion", #"puma", #"snow leopard", nil]];
// and more for the other two setters
Alternately, you can set these default values in the init for the wordDictionary class:
- (id)init {
self = [super init];
if (self) {
[self setCatList:[NSMutableArray arrayWithObjects:#"lion", #"puma", #"snow leopard", nil]];
}
return self;
}
The former is better in most cases, but you may have a good reason to pre-populate your model for all instances of the class.
Assuming you called setCatList:, setDogList: and setStandardDictionary: before. Probably that causing is this :
NSString *chosenKey = [self.dictionary selectKey];
change into this :
NSString *chosenKey = [self selectKey];
UPDATE
I'm trying to make your life easier. no need to create your object if you don't need the most.
- (NSMutableArray*)getCatList
{
return [NSMutableArray arrayWithObjects:#"lion", #"puma", #"snow leopard", nil];
}
- (NSMutableArray*)getDogList
{
return [NSMutableArray arrayWithObjects:#"pit bull", #"pug", #"chihuahua", nil];
}
-(NSMutableDictionary*)getStandardDictionary
{
NSMutableDictionary *standardDictionary = [NSMutableDictionary new];
[standardDictionary setObject:[self getCatList] forKey:#"CAT"];
[standardDictionary setObject:[self getDogList] forKey:#"DOG"];
return [standardDictionary autorelease];
}
- (NSString*)selectKey
{
NSMutableDictionary *standardDictionary = [self getStandardDictionary];
NSInteger keyCount = [[standardDictionary allKeys] count];
NSInteger randomKeyIndex = arc4random() % keyCount;
NSString *randomKey = [[standardDictionary allKeys] objectAtIndex:randomKeyIndex];
return randomKey;
}
- (IBAction)changeGreeting:(UIButton*)sender {
// NSString *chosenKey = [self selectKey];
//NSString *labelText = [[NSString alloc] initWithFormat:#"%#", chosenKey];
self.label.text = [self selectKey]; //no need to convert it to NSString again
}
Two things to consider:
I don't see you calling these:
setCatList:(NSMutableArray*)catList;
setDogList:(NSMutableArray*)dogList;
You use self.catList and self.dogList, but neither of those are synthesized, instead you have beatList and meList synthesized
Change the synthesizes to the catList and dogList, and make sure you call the set list methods, and then you should make some progress.
Suppose I have a function
- (NSString *)fullNameCopy {
return [[NSString alloc] initWithFormat:#"%# %#", self.firstName, self.LastName];
}
Can somebody tell me how to call this function, how to assign its value to a new object, and how then to release it, avoiding memory leaks, and bad access.
Would it be like
NSSting *abc = [object fullNameCopy];
// Use it and release
[abc release];
or I should alloc abc string too ?
Update:
The point here, Can I return non-autorelease objects from a function and then release them in the calling function. As per Obj-C function naming conventions, a function name containing alloc or copy should return object assuming that calling function has the ownership.
As in above case, my function "fullNameCopy" return a non-autoreleased abject, and I want to release them in the calling function.
You are right. Since the method name contains the word ‘copy’, Cocoa convention dictates that the method returns an object that is owned by the caller. Since the caller owns that object, it is responsible for releasing it. For example:
- (void)someMethod {
NSString *abc = [object fullNameCopy];
// do something with abc
[abc release];
}
Alternatively, you could use -autorelease instead of -release:
- (void)someMethod {
NSString *abc = [[object fullNameCopy] autorelease];
// do something with abc
}
Refer this post
UPDATE:
- (NSString *)fullNameCopy {
NSString *returnString = [NSString stringWithFormat:#"%# %#", self.firstName, self.LastName]; // Autorelease object.
return returnString;
}
-(void) someFunction {
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
NSString *fullName = [self fullNameCopy];
[pool release]
}
Like This:
- (NSString *)fullName {
NSString * retVal = [[NSString alloc] initWithFormat:#"%# %#", self.firstName, self.LastName];
return [retVal autoRelease];
}
Then
NSSting *abc = [object fullName];
return [[[NSString alloc] initWithFormat:#"%# %#", self.firstName, self.LastName]autorelease];
Testing my app on the device it returns a leak whe i call the copy of a custom object ande i can't understand why.
this is the call:
NSMutableArray *arr = [[NSMutableArray alloc] initWithCapacity:5];
for (SinglePart *sp in [copyFrom partList]) {
[arr addObject:[sp copy]];
}
self.partList = arr;
[arr release];
this is the method:
- (id)copyWithZone:(NSZone *)zone {
SinglePart *copy = [[[self class] allocWithZone:zone] initWithSinglePart:self];
[copy loadImage];
return copy;
}
this is the method that is called by copyWithZone:
- (id)initWithSinglePart:(SinglePart *)copyFrom {
if (self = [super init]) {
self.imagePath = [copyFrom.imagePath copy];
self.color = [UIColor colorWithCGColor:copyFrom.color.CGColor];
self.hasOwnColor = copyFrom.hasOwnColor;
self.blendingMode = copyFrom.blendingMode;
}
return self;
}
copy returns a new object with retain count 1. Meaning you need to release the new object, which you are not doing.
NSMutableArray *arr = [[NSMutableArray alloc] initWithCapacity:5];
for (SinglePart *sp in [copyFrom partList]) {
SingPart *theCopy = [sp copy];
[arr addObject:theCopy];
[theCopy release];
}
self.partList = arr;
[arr release];
Even your custom copyWithZone: method inits an object, but does not autorelease it, which is the expected behavior of a copy method. Copy must be balanced just like a retain or init, meaning you must balance it with release at some point.
Lastly, your initWithSinglePart: method leaks the imagePath as well. In this case if you declare the imagePath property as copy instead of retain then you don't need to do this manually at all. Then you simply assign the value and let the property setter do it for you.
// Header
#property (copy) NSString *imagePath;
// Now this will do the copy for you
self.imagePath = copyFrom.imagePath;
Also, is the property imagePath defined with retain or copy semantics?
If so you need to add an autorelease here:
self.imagePath = [[copyFrom.imagePath copy] autorelease];
because the default setter will retain/copy it too.
So, you either need to autorelease, or omit the "self." to bypass the default setter.
You are making a copy of sp and then adding it to the array. The array then retains the object so your retain count is now 2.
In the end you release arr, thus making the retain count of it's items 1.
You should either add another release to the sp objects, or not use copy.
Try this:
self.partList = [NSMutableArray arrayWithCapacity:5];
for (SinglePart *sp in [copyFrom partList]) {
[arr addObject:sp];
}
NSMutableArray count is returning zero after adding objects to it, its been an hour of hacking away trying to figure out why, and I'm still stuck, so that brings me here.
Any ideas based off the following code, what the problem is?
the object 'search' is a custom class defined in the header set as a pointer, with retain, nonatomic attributes.
- (NSMutableArray *) populateArrayFromPlist{
NSLog(#"Populate Array from PList");
NSDictionary *dictionary;
// read "foo.plist" from application bundle
NSString *path = [[NSBundle mainBundle] bundlePath];
NSString *finalPath = [path stringByAppendingPathComponent:#"asearch.plist"];
dictionary = [NSDictionary dictionaryWithContentsOfFile:finalPath];
for (id key in dictionary)
{
search = [[ASearch alloc] init];
[dictionary valueForKey:key];
[search setID:[[dictionary valueForKey:key] intValue] ];
//[[search searchString] initWithString: key];
search.searchString = [[NSMutableString alloc] initWithString: key];
if (search == nil) {
printf("Let me know now\n\n\n\n");
}
NSLog(#"%#", [search searchString]);
NSLog(#"Setting string Value: %s\n", [key cString]);
NSLog(#"Setting ID Value: %i\n", [[dictionary valueForKey:key] intValue]);
//NSLog(#"aSearchArray count == %i", [[aSearchArray count] intValue]);
[aSearchArray addObject:search];
NSLog(#"aSearchArray count == %i", [aSearchArray count] );
aSearchArray is a nil object that is the only reason why you are getting count as zero.
For more confirmation just create a new local array and try to add your object to it.
You will get a proper count