Unarchive custom object with secure coding in iOS

Question

I'm encoding an array of objects that conform to NSSecureCoding successfully like this.

NSData *data = [NSKeyedArchiver archivedDataWithRootObject:array requiringSecureCoding:YES error:nil];

How do I unarchive this data? I'm trying like this but it's returning nil.

NSError *error = nil;
NSArray<MyClass *> *array = [NSKeyedUnarchiver unarchivedObjectOfClass:[NSArray class] fromData:data error:&error];

This is the error it returns.

The data couldn’t be read because it isn’t in the correct format.

Answer 1

Here is a simple example

@interface Secure:NSObject<NSSecureCoding> {
    NSString* name;
}
@property NSString* name;
@end

@implementation Secure
@synthesize name;

// Confirms to NSSecureCoding
+ (BOOL)supportsSecureCoding {
    return true;
}

- (void)encodeWithCoder:(nonnull NSCoder *)coder {
    [coder encodeObject:self.name forKey: @"name"];
}

- (nullable instancetype)initWithCoder:(nonnull NSCoder *)coder {
    self = [self init];
    if (self){
        self.name = [coder decodeObjectOfClass:[NSString class] forKey:@"name"];
    }
    return  self;
}

@end

Usage

Secure *archive = [[Secure alloc] init];
    archive.name = @"ARC";
NSArray* array = @[archive];
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:array requiringSecureCoding:YES error:nil];
NSArray<Secure *> *unarchive = [NSKeyedUnarchiver unarchivedObjectOfClass:[NSObject class] fromData:data error:nil];
NSLog(@"%@", unarchive.firstObject.name);