How to unarchive BOOL property with NSKeyedUnarchiver? - ios

Question

I have class for playing sound in app.
I implemented on/off switch(on GUI), for disabling and enablining sound play.
I am using BOOL property for that and this is working.
Now I am trying to implement saving that BOOL (is sound on/off) in file so that next time when app is started state is automatically restored.
For that I am using NSCoding protocol, archiving is working but I have problem with unarchiving.
My app will not start it will just show black screen.
This is my code, only part that I think it is important.
GTN_Sound.h
#import <Foundation/Foundation.h>
#import <AudioToolbox/AudioToolbox.h> // for playing sound
#interface GTN_Sound : NSObject <NSCoding>
#property(nonatomic, readwrite, unsafe_unretained) BOOL isSoundOn;
+ (id)sharedManager;
- (void)playWinSound;
- (void)playLoseSound;
#end
GTN_Sound.m
#pragma mark - NSCoding Methods
- (void)encodeWithCoder:(NSCoder *)aCoder
{
[aCoder encodeBool:self.isSoundOn forKey:#"isSoundOn"];
}
- (instancetype)initWithCoder:(NSCoder *)aDecoder
{
self = [GTN_Sound sharedManager];
if (self) {
_isSoundOn = [aDecoder decodeBoolForKey:#"isSoundOn"];
}
return self;
}
I think that code is so far so good ?
Continuation of GTN_Sound.m
#pragma mark - itemArchivePath Method
- (NSString *)itemArchivePath
{
// Make sure that the first argument is NSDocumentDirectory
// and not NSDocumentationDirectory
NSArray *documentDirectories =
NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
// Get the one document directory from that list
NSString *documentDirectory = [documentDirectories firstObject];
return [documentDirectory stringByAppendingPathComponent:#"sound.archive"];
}
#pragma mark - custom seter Method
- (void)setIsSoundOn:(BOOL)theBoolean {
NSLog(#"My custom setter\n");
if(_isSoundOn != theBoolean){
_isSoundOn = theBoolean;
NSString *path = [self itemArchivePath];
[NSKeyedArchiver archiveRootObject:self toFile:path]; // this is doing save
}
}
It is done that for every time when switch on GUI is changed I do the savings.
This look fine from my side, because I am not expecting that user will change this many times.
Now the unarchiving comes and I thin that here are some problems.
#pragma mark - Singleton Methods
+ (id)sharedManager {
static GTN_Sound *sharedMyManager = nil;
// to be thread safe
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedMyManager = [[self alloc] initPrivate];
});
return sharedMyManager;
}
- (instancetype)init
{
#throw [NSException exceptionWithName:#"Singleton"
reason:#"Use +[GTN_Sound sharedManager]"
userInfo:nil];
return nil;
}
// Here is the real (secret) initializer
- (instancetype)initPrivate
{
self = [super init];
if (self) {
NSString *path = [self itemArchivePath]; // do as iVar, for futture
self = [NSKeyedUnarchiver unarchiveObjectWithFile:path];
//_isSoundOn = [NSKeyedUnarchiver unarchiveObjectWithFile:path];
}
return self;
}
I think that problem is in this line
self = [NSKeyedUnarchiver unarchiveObjectWithFile:path];
But have no idea how to fix it.
I have read that when I am doing archiving, that I need to archive all properties of object.
Does this apply to private ivars also ?
Any help is appreciated.
Thanks

Answer 1

You can only archive NSObject inheriting objects. ie. NSNumber
[NSKeyedArchiver archiveRootObject:#YES toFile:path]; //to save
_isSoundOn = [[NSKeyedUnarchiver unarchiveObjectWithFile:path] boolValue]; //to load