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How to make a deep copy using copyWithZone to duplicate the structure?

I have a class representing a structure.

This class with the name Objecthas the following properties

@property (nonatomic, strong) NSArray *children;
@property (nonatomic, assign) NSInteger type;
@property (nonatomic, strong) NSString *name;
@property (nonatomic, weak) id parent;

childrenis an array of other Objects. parent- weak reference to the parent object.

I am trying to copy and paste a branch of this structure. If the root object is selected, it is obvious that it parentis zero. If the object is not a root, it has a parent.

To do this, view objects Objectmust conform to NSCopyingand NSCoding.

This is my implementation of these protocols in this class.

-(id) copyWithZone: (NSZone *) zone
{
  Object *obj = [[Object allocWithZone:zone] init];
  if (obj) {
    [obj setChildren:_children];
    [obj setType:_type];
    [obj setName:_name];
    [obj setParent:_parent];
   }

  return obj;
}

- (void)encodeWithCoder:(NSCoder *)coder {
  [coder encodeObject:@(self.type) forKey:@"type"];
  [coder encodeObject:self.name forKey:@"name"];
  NSData *childrenData = [NSKeyedArchiver archivedDataWithRootObject:self.children];
  [coder encodeObject:childrenData forKey:@"children"];
  [coder encodeConditionalObject:self.parent forKey:@"parent"]; //*
}

- (id)initWithCoder:(NSCoder *)coder {

  self = [super init];

  if (self) {

    _type = [[coder decodeObjectForKey:@"type"] integerValue];
    _name = [coder decodeObjectForKey:@"name"];
    _parent = [coder decodeObjectForKey:@"parent"]; //*
    NSData *childrenData = [coder decodeObjectForKey:@"children"];
    _children = [NSKeyedUnarchiver unarchiveObjectWithData:childrenData];
    _parent = nil;
  }

  return self;

}

, , self.parent initWithCoder: encodeWithCoder:, - = nil.

, . - . , Object.

ObjectA > ObjectB > ObjectC

encoderWithCoder: ObjectA, ObjectB ObjectC, ObjectB, , ObjectA, , , . .

/ ?

, , . , , .

. , //*, , _parent - nil initWithCoder: , parent

+4
2

[coder encodeConditionalObject:self.parent forKey:@"parent"]. -decodeObjectForKey: .

, - - , - . , , . nil.

, children, . , Object, (). ​​ . [coder encodeObject:self.children forKey:@"children"] _children = [coder decodeObjectForKey:@"children"].

-copyWithZone:. , , . , , . .

NSCoding . , . :

-(id) copyWithZone: (NSZone *) zone
{
  NSData* selfArchive = [NSKeyedArchiver archivedDataWithRootObject:self];
  return [NSKeyedUnarchiver unarchiveObjectWithData:selfArchive];
}

. , , .. .

, , (.. type name). , , , , , .

, -copyWithZone: [self class] Object, . , - Object -copyWithZone: super , Object (). :

-(id) copyWithZone: (NSZone *) zone
{
  Object *obj = [[[self class] allocWithZone:zone] init];
  if (obj) {
    [obj setType:_type];
    [obj setName:_name];
   }

  return obj;
}
+4

@KenThomases ,

, , children ?

. encodeConditionalObject:forKey: . :

NSData *childrenData = [NSKeyedArchiver archivedDataWithRootObject:self.children];

. , , :

[coder encodeObject:self.children forKey:@"children"];

NSKeyedArchiver.

:

_parent = nil;

.

+1

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