NSObject-Safe

Update 2019.07.04

• add overflow/negative support for NSRange

1: negative value
    - NSUInteger  > NSIntegerMax
2: overflow
    - (a+ b) > a

Update 2018.11.20

• add thread-safe support

Update 2018.6.26

• remove unused swizze for NSDictionary objectForKey:
• more class cluster support

NSArray
    __NSArrayI_Transfer, __NSArrayReversed, __NSFrozenArrayM, __NSCFArray
NSString
    NSTaggedPointerString, __NSCFString, _NSCFConstantString
NSData
    NSConcreteData, NSConcreteMutableData, _NSZeroData, _NSInlineData, __NSCFData

Warn:

• Compile NSObjectSafe.m with -fno-objc-arc, otherwise it will cause strange release error: [UIKeyboardLayoutStar release]: message sent to deallocated instance
• Conflict with MultiDelegate

Desciption

• Swizzle commonly used function of Foundation container to prevent nil crash
• Hook forwardInvocation to catch unrecognized selector exception
• Assert in Debug and log in Release

Usage:

• involve NSObjectSafe.h/NSObjectSafe.m as build phases

unrecognized selector protection

• NSSafeProxy: unrecognized selector [print:] sent to A

@interface A : NSObject
- (void)print:(NSString*)msg;
@end
@implementation A
@end

Object Literals

NSArray* item = nil;
NSArray * items = @[@"a",@"b", item ,@"c"];
NSLog(@"%@", items);

NSString* key = nil;
NSString* value = nil;
NSLog(@"%@", @{@"b":@"c",key:value, @"e":value});

Swizzle Functions:

• NSObject(Swizzle):

+ (void)swizzleClassMethod:(SEL)origSelector withMethod:(SEL)newSelector;
- (void)swizzleInstanceMethod:(SEL)origSelector withMethod:(SEL)newSelector;

• NSObject(Safe)

- (void) addObserver:(NSObject *)observer forKeyPath:(NSString *)keyPath 
						options:(NSKeyValueObservingOptions)options context:(void *)context;
- (void) removeObserver:(NSObject *)observer forKeyPath:(NSString *)keyPath;

• NSString

+ (NSString*) stringWithUTF8String:(const char *)nullTerminatedCString;
+ (nullable instancetype) stringWithCString:(const char *)cString encoding:(NSStringEncoding)enc;
- (nullable instancetype) initWithCString:(const char *)nullTerminatedCString encoding:(NSStringEncoding)encoding;
- (NSString *)stringByAppendingString:(NSString *)aString;

• NSMutableString

- (nullable instancetype) safeInitWithCString:(const char *)nullTerminatedCString encoding:(NSStringEncoding)encoding;
- (void) appendString:(NSString *)aString;
- (void) insertString:(NSString *)aString atIndex:(NSUInteger)loc;
- (void) deleteCharactersInRange:(NSRange)range;
- (NSString *)stringByAppendingString:(NSString *)aString;

• NSArray

+ (instancetype) arrayWithObject:(id)anObject;
- (id) objectAtIndex:(NSUInteger)index;

• NSMutableArray

- (void) addObject:(id)anObject;
- (id) objectAtIndex:(NSUInteger)index;
- (void) insertObject:(id)anObject atIndex:(NSUInteger)index;
- (void) removeObjectAtIndex:(NSUInteger)index;
- (void) replaceObjectAtIndex:(NSUInteger)index withObject:(id)anObject;
- (void) removeObjectsInRange:(NSRange)range;

• NSDictionary

+ (instancetype) dictionaryWithObject:(id)object forKey:(id)key;
- (id) objectForKey:(id)aKey;

• NSMutableDictionary

- (id) objectForKey:(id)aKey;
- (void) setObject:(id)anObject forKey:(id)aKey;
- (void) removeObjectForKey:(id)aKey;

• NSSet

+ (instancetype)setWithObject:(id)object;

• NSMutableSet

- (void) addObject:(id)object;
- (void) removeObject:(id)object;

• NSOrderedSet

+ (instancetype)orderedSetWithObject:(id)object;
- (instancetype)initWithObject:(id)object;
- (id)objectAtIndex:(NSUInteger)idx;

• NSMutableOrderedSet

- (id)objectAtIndex:(NSUInteger)idx;
- (void)addObject:(id)object;
- (void)insertObject:(id)object atIndex:(NSUInteger)idx;
- (void)removeObjectAtIndex:(NSUInteger)idx;
- (void)replaceObjectAtIndex:(NSUInteger)idx withObject:(id)object;

• NSUserDefault

- (id) objectForKey:(NSString *)defaultName;
- (NSInteger) integerForKey:(NSString *)defaultName;
- (BOOL) boolForKey:(NSString *)defaultName;
- (void) setObject:(id)value forKey:(NSString*)aKey;
- (void) removeObjectForKey:(NSString*)aKey;