Open ClassFoundation5.9.0

NSCoder

The NSCoder abstract class declares the interface used by concrete subclasses to transfer objects and other values between memory and some other format. This capability provides the basis for archiving (where objects and data items are stored on disk) and distribution (where objects and data items are copied between different processes or threads). The concrete subclasses provided by Foundation for these purposes are NSKeyedArchiver and NSKeyedUnarchiver. Concrete subclasses of NSCoder are referred to in general as coder classes, and instances of these classes as coder objects (or simply coders). A coder object that can only encode values is referred to as an encoder object, and one that can only decode values as a decoder object.

class NSCoder

NSCoder operates on objects, scalars, C arrays, structures, and strings, and on pointers to these types. It does not handle types whose implementation varies across platforms, such as UnsafeRawPointer, closures, and long chains of pointers. A coder object stores object type information along with the data, so an object decoded from a stream of bytes is normally of the same class as the object that was originally encoded into the stream. An object can change its class when encoded, however; this is described in Archives and Serializations Programming Guide.

Superclasses

class NSObject
The root class of most Foundation class hierarchies.

Citizens in Foundation

Conformances

protocol CustomDebugStringConvertible
A type with a customized textual representation suitable for debugging purposes.
protocol CustomStringConvertible
A type with a customized textual representation.
protocol Equatable
A type that can be compared for value equality.
protocol Hashable
A type that can be hashed into a Hasher to produce an integer hash value.
protocol NSObjectProtocol
The NSObjectProtocol groups methods that are fundamental to all Foundation objects.

Members

var allowedClasses: [AnyClass]?
The array of coded classes allowed for secure coding.
var allowsKeyedCoding: Bool
A Boolean value that indicates whether the receiver supports keyed coding of objects.
var decodingFailurePolicy: NSCoder.DecodingFailurePolicy
var error: Error?
var requiresSecureCoding: Bool
Boolean value that indicates whether the coder requires secure coding.
var systemVersion: UInt32
The system version in effect for the archive.
func containsValue(forKey: String) -> Bool
Returns a Boolean value that indicates whether an encoded value is available for a string.
func decodeArray(ofObjCType: UnsafePointer<Int8>, count: Int, at: UnsafeMutableRawPointer)
func decodeBool(forKey: String) -> Bool
Decodes and returns a Boolean value that was previously encoded with encode(_:forKey:) and associated with the string key.
func decodeCInt(forKey: String) -> Int32
Decodes and returns an int value that was previously encoded with encodeCInt(_:forKey:) or encode(_:forKey:) and associated with the string key.
func decodeData() -> Data?
Decodes and returns a Data object that was previously encoded with encode(_:). Subclasses must override this method.
func decodeDouble(forKey: String) -> Double
Decodes and returns a double value that was previously encoded with encodeCInt(_:forKey:) or encode(_:forKey:) and associated with the string key.
func decodeFloat(forKey: String) -> Float
Decodes and returns a float value that was previously encoded with encodeCInt(_:forKey:) or encode(_:forKey:) and associated with the string key.
func decodeInt32(forKey: String) -> Int32
Decodes and returns a 32-bit integer value that was previously encoded with encodeCInt(_:forKey:) or encode(_:forKey:) and associated with the string key.
func decodeInt64(forKey: String) -> Int64
Decodes and returns a 64-bit integer value that was previously encoded with encodeCInt(_:forKey:) or encode(_:forKey:) and associated with the string key.
func decodeInteger(forKey: String) -> Int
Decodes and returns an integer value that was previously encoded with encodeCInt(_:forKey:) or encode(_:forKey:) and associated with the string key.
func decodeObject() -> Any?
Decodes an Objective-C object that was previously encoded with any of the encode...Object methods.
func decodeObject(forKey: String) -> Any?
Decodes and returns an Objective-C object that was previously encoded with encode(_:forKey:) or encodeConditionalObject(_:forKey:) and associated with the string key.
func decodeObject<DecodedObjectType>(of: DecodedObjectType.Type, forKey: String) -> DecodedObjectType?
func decodeObject(of: [AnyClass]?, forKey: String) -> Any?
Decodes an object for the key, restricted to the specified classes.
func decodePoint() -> NSPoint
func decodePoint(forKey: String) -> NSPoint
func decodePropertyList() -> Any?
Decodes a property list that was previously encoded with encodePropertyList(_:).
func decodePropertyList(forKey: String) -> Any?
Returns a decoded property list for the specified key.
func decodeRect() -> NSRect
func decodeRect(forKey: String) -> NSRect
func decodeSize() -> NSSize
func decodeSize(forKey: String) -> NSSize
func decodeValue(ofObjCType: UnsafePointer<Int8>, at: UnsafeMutableRawPointer)
Decodes a single value, whose Objective-C type is given by type.
func encode(Data)
Encodes a given Data object.
func encode(NSRect)
func encode(NSSize)
func encode(NSPoint)
func encode(Any?)
Encodes object.
func encode(NSRect, forKey: String)
func encode(NSSize, forKey: String)
func encode(NSPoint, forKey: String)
func encode(Bool, forKey: String)
Encodes boolv and associates it with the string key.
func encode(Double, forKey: String)
Encodes realv and associates it with the string key.
func encode(Float, forKey: String)
Encodes realv and associates it with the string key.
func encode(Int, forKey: String)
Encodes a given integer number and associates it with a given key.
func encode(Int32, forKey: String)
Encodes the 32-bit integer intv and associates it with the string key.
func encode(Int64, forKey: String)
Encodes the 64-bit integer intv and associates it with the string key.
func encode(Any?, forKey: String)
Encodes the object objv and associates it with the string key.
func encodeArray(ofObjCType: UnsafePointer<Int8>, count: Int, at: UnsafeRawPointer)
Encodes an array of count items, whose Objective-C type is given by type.
func encodeBycopyObject(Any?)
Can be overridden by subclasses to encode anObject so that a copy, rather than a proxy, is created upon decoding.
func encodeByrefObject(Any?)
Can be overridden by subclasses to encode anObject so that a proxy, rather than a copy, is created upon decoding.
func encodeBytes(UnsafeRawPointer?, length: Int)
Encodes a buffer of data whose types are unspecified.
func encodeBytes(UnsafePointer<UInt8>?, length: Int, forKey: String)
Encodes a buffer of data, bytesp, whose length is specified by lenv, and associates it with the string key.
func encodeConditionalObject(Any?)
Can be overridden by subclasses to conditionally encode object, preserving common references to that object.
func encodeConditionalObject(Any?, forKey: String)
Conditionally encodes a reference to objv and associates it with the string key only if objv has been unconditionally encoded with encode(_:forKey:).
func encodePropertyList(Any)
Encodes the property list aPropertyList.
func encodeRootObject(Any)
Can be overridden by subclasses to encode an interconnected group of Objective-C objects, starting with rootObject.
func encodeValue(ofObjCType: UnsafePointer<Int8>, at: UnsafeRawPointer)
Must be overridden by subclasses to encode a single value residing at addr, whose Objective-C type is given by type.
func failWithError(Error)
func version(forClassName: String) -> Int
This method is present for historical reasons and is not used with keyed archivers.
func withDecodedUnsafeBytes<ResultType>(forKey: String, body: (UnsafeRawBufferPointer?) throws -> ResultType) rethrows -> ResultType
enum DecodingFailurePolicy
Describes the action an NSCoder should take when it encounters decode failures (e.g. corrupt data) for non-TopLevel decodes. Darwin platfrom supports exceptions here, and there may be other approaches supported in the future, so its included for completeness.
func withDecodedUnsafeBufferPointer<ResultType>(forKey: String, body: (UnsafeBufferPointer<UInt8>?) throws -> ResultType) rethrows -> ResultType

Subclasses

class NSKeyedArchiver
NSKeyedArchiver, a concrete subclass of NSCoder, provides a way to encode objects (and scalar values) into an architecture-independent format that can be stored in a file. When you archive a set of objects, the class information and instance variables for each object are written to the archive. NSKeyedArchiver’s companion class, NSKeyedUnarchiver, decodes the data in an archive and creates a set of objects equivalent to the original set.
class NSKeyedUnarchiver