decodeTopLevelObjectOfClasses:forKey:error:
Decode an object as one of several expected types, failing if the archived type does not match.
Declaration
- (id) decodeTopLevelObjectOfClasses:(NSSet<Class> *) classes forKey:(NSString *) key error:(NSError **) error;Parameters
- classes:
A set of expected classes that the object being decoded should match at least one of.
- key:
The archive key indicating the member to decode.
- error:
On return, an Nserror indicating why decoding failed, or
nilif no error occurred.
Return Value
The decoded object, or nil if decoding fails.
Discussion
This method is equivalent to decodeObject(of:forKey:), but allows you to specify a set of classes that the decoded object can match. If requiresSecureCoding is true, the decoded object’s class must be a member of the classes parameter, or a sublcass of a member.