NSCoder class reference

Authors

Andrew Kachites McCallum (mccallum@gnu.ai.mit.edu)
Adam Fedor (fedor@boulder.colorado.edu)

Date: Generated at 2023-12-20 19:35:39 -0500

Software documentation for the NSCoder class

NSCoder : NSObject

Declared in:

Foundation/NSCoder.h

Availability: OpenStep

Top-level class defining methods for use when archiving (encoding) objects to a byte array or file, and when restoring (decoding) objects. Generally only subclasses of this class are used directly - NSArchiver , NSUnarchiver , NSKeyedArchiver , NSKeyedUnarchiver , or NSPortCoder .

NSPortCoder is used within the distributed objects framework. For archiving to/from disk, the Keyed... classes are preferred for new implementations, since they provide greater forward/backward compatibility in the face of class changes.

Method summary

allowsKeyedCoding

- (BOOL) allowsKeyedCoding;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Returns a flag indicating whether the receiver supported keyed coding. the default implementation returns NO. Subclasses supporting keyed coding must override this to return YES.

containsValueForKey:

- (BOOL) containsValueForKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Returns a class indicating whether an encoded value corresponding to aKey exists.

decodeArrayOfObjCType: count: at:

- (void) decodeArrayOfObjCType: (const char*)type count: (NSUInteger)count at: (void*)address;

Availability: OpenStep

Decodes array of count structures or objects of given type, which may be obtained through the ' @encode(...) ' compile-time operator. Usually this is used for primitives though it can be used for objects as well. Objects will be retained and you must release them.

decodeBoolForKey:

- (BOOL) decodeBoolForKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Returns a boolean value associated with aKey. This value must previously have been encoded using -encodeBool:forKey:

decodeBytesForKey: returnedLength:

- (const uint8_t*) decodeBytesForKey: (NSString*)aKey returnedLength: (NSUInteger*)alength;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Returns a pointer to a byte array associated with aKey.
Returns the length of the data in aLength.
This value must previously have been encoded using -encodeBytes:length:forKey:

decodeBytesWithReturnedLength:

- (void*) decodeBytesWithReturnedLength: (NSUInteger*)l;

Availability: OpenStep

Retrieve bytes directly from archive.

decodeDataObject

- (NSData*) decodeDataObject;

Availability: OpenStep

Decode an instance of NSData .

decodeDoubleForKey:

- (double) decodeDoubleForKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Returns a double value associated with aKey. This value must previously have been encoded using -encodeDouble:forKey: or -encodeFloat:forKey:

decodeFloatForKey:

- (float) decodeFloatForKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Returns a float value associated with aKey. This value must previously have been encoded using -encodeFloat:forKey: or -encodeDouble:forKey:
Precision may be lost (or an exception raised if the value will not fit in a float) if the value was encoded using -encodeDouble:forKey: ,

decodeInt32ForKey:

- (int32_t) decodeInt32ForKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Returns a 32-bit integer value associated with aKey. This value must previously have been encoded using -encodeInt:forKey: , -encodeInt32:forKey: , or -encodeInt64:forKey: .
An exception will be raised if the value does not fit in a 32-bit integer.

decodeInt64ForKey:

- (int64_t) decodeInt64ForKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Returns a 64-bit integer value associated with aKey. This value must previously have been encoded using -encodeInt:forKey: , -encodeInt32:forKey: , or -encodeInt64:forKey: .

decodeIntForKey:

- (int) decodeIntForKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Returns an integer value associated with aKey. This value must previously have been encoded using -encodeInt:forKey: , -encodeInt32:forKey: , or -encodeInt64:forKey: .
An exception will be raised if the value does not fit in an integer.

decodeIntegerForKey:

- (NSInteger) decodeIntegerForKey: (NSString*)key;

Availability: MacOS-X 10.5.0

Subclasses must override this method.

Decodes an NSInteger associated with the key.

decodeObject

- (id) decodeObject;

Availability: OpenStep

Decodes a generic object. Usually the class will be read from the archive, an object will be created through an alloc call, then that class will be sent an [<NSCoding>-initWithCoder:] message.

decodeObjectForKey:

- (id) decodeObjectForKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Returns an object value associated with aKey. This value must previously have been encoded using -encodeObject:forKey: or -encodeConditionalObject:forKey:

decodeObjectOfClass: forKey:

- (id) decodeObjectOfClass: (Class)cls forKey: (NSString*)key;

Availability: MacOS-X 10.8.0

Description forthcoming.

decodeObjectOfClasses: forKey:

- (id) decodeObjectOfClasses: (NSSet*)classes forKey: (NSString*)key;

Availability: MacOS-X 10.8.0

Description forthcoming.

decodePoint

- (NSPoint) decodePoint;

Availability: OpenStep

Decodes a point structure.

decodePropertyList

- (id) decodePropertyList;

Availability: OpenStep

Decodes a property list from the archive previously stored through a call to -encodePropertyList: .

decodeRect

- (NSRect) decodeRect;

Availability: OpenStep

Decodes a rectangle structure.

decodeSize

- (NSSize) decodeSize;

Availability: OpenStep

Decodes a size structure.

decodeValueOfObjCType: at:

- (void) decodeValueOfObjCType: (const char*)type at: (void*)address;

Availability: OpenStep

Decodes structure or object of given type, which may be obtained through the ' @encode(...) ' compile-time operator. Usually this is used for primitives though it can be used for objects as well, in which case you are responsible for releasing them.

decodeValuesOfObjCTypes: ,...

- (void) decodeValuesOfObjCTypes: (const char*)types,...;

Availability: OpenStep

Multiple version of -decodeValueOfObjCType:at: .

encodeArrayOfObjCType: count: at:

- (void) encodeArrayOfObjCType: (const char*)type count: (NSUInteger)count at: (const void*)array;

Availability: OpenStep

Encodes array of count structures or objects of given type, which may be obtained through the ' @encode(...) ' compile-time operator. Usually this is used for primitives though it can be used for objects as well.

encodeBool: forKey:

- (void) encodeBool: (BOOL)aBool forKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Encodes aBool and associates the encoded value with aKey.

encodeBycopyObject:

- (void) encodeBycopyObject: (id)anObject;

Availability: OpenStep

Can be ignored.

encodeByrefObject:

- (void) encodeByrefObject: (id)anObject;

Availability: OpenStep

Can be ignored.

encodeBytes: length:

- (void) encodeBytes: (void*)d length: (NSUInteger)l;

Availability: OpenStep

Stores bytes directly into archive.

encodeBytes: length: forKey:

- (void) encodeBytes: (const uint8_t*)aPointer length: (NSUInteger)length forKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Encodes the data of the specified length and pointed to by aPointer, and associates the encoded value with aKey.

encodeConditionalObject:

- (void) encodeConditionalObject: (id)anObject;

Availability: OpenStep

Encode object if it is/will be encoded unconditionally by this coder, otherwise store a nil.

encodeConditionalObject: forKey:

- (void) encodeConditionalObject: (id)anObject forKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Encodes anObject and associates the encoded value with aKey, but only if anObject has already been encoded using -encodeObject:forKey:

encodeDataObject:

- (void) encodeDataObject: (NSData*)data;

Availability: OpenStep

Encode an instance of NSData .

encodeDouble: forKey:

- (void) encodeDouble: (double)aDouble forKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Encodes aDouble and associates the encoded value with aKey.

encodeFloat: forKey:

- (void) encodeFloat: (float)aFloat forKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Encodes aFloat and associates the encoded value with aKey.

encodeInt32: forKey:

- (void) encodeInt32: (int32_t)anInteger forKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Encodes 32 bit integer and associates the encoded value with aKey.

encodeInt64: forKey:

- (void) encodeInt64: (int64_t)anInteger forKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Encodes a 64 bit integer and associates the encoded value with aKey.

encodeInt: forKey:

- (void) encodeInt: (int)anInteger forKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Encodes an int and associates the encoded value with aKey.

encodeInteger: forKey:

- (void) encodeInteger: (NSInteger)anInteger forKey: (NSString*)key;

Availability: MacOS-X 10.5.0

Subclasses must override this method.

Encodes an NSInteger and associates the encoded value with key.

encodeObject:

- (void) encodeObject: (id)anObject;

Availability: OpenStep

Encodes a generic object. This will usually result in an [<NSCoding>-encodeWithCoder:] message being sent to anObject so it can encode itself.

encodeObject: forKey:

- (void) encodeObject: (id)anObject forKey: (NSString*)aKey;

Availability: MacOS-X 10.0.0

Subclasses must override this method.

Encodes anObject and associates the encoded value with aKey.

encodePoint:

- (void) encodePoint: (NSPoint)point;

Availability: OpenStep

Encodes a point structure.

encodePropertyList:

- (void) encodePropertyList: (id)plist;

Availability: OpenStep

Encodes a property list by calling [NSSerializer -serializePropertyList:], then encoding the resulting NSData object.

encodeRect:

- (void) encodeRect: (NSRect)rect;

Availability: OpenStep

Encodes a rectangle structure.

encodeRootObject:

- (void) encodeRootObject: (id)rootObject;

Availability: OpenStep

Store object and objects it refers to in archive (i.e., complete object graph).

encodeSize:

- (void) encodeSize: (NSSize)size;

Availability: OpenStep

Encodes a size structure.

encodeValueOfObjCType: at:

- (void) encodeValueOfObjCType: (const char*)type at: (const void*)address;

Availability: OpenStep

Encodes structure or object of given type, which may be obtained through the ' @encode(...) ' compile-time operator. Usually this is used for primitives though it can be used for objects as well.

encodeValuesOfObjCTypes: ,...

- (void) encodeValuesOfObjCTypes: (const char*)types,...;

Availability: OpenStep

Multiple version of -encodeValueOfObjCType:at: .

objectZone

- (NSZone*) objectZone;

Availability: OpenStep

Returns zone being used to allocate memory for decoded objects.

requiresSecureCoding

- (BOOL) requiresSecureCoding;

Availability: MacOS-X 10.8.0

Description forthcoming.

setObjectZone:

- (void) setObjectZone: (NSZone*)zone;

Availability: OpenStep

Sets zone to use for allocating memory for decoded objects.

setRequiresSecureCoding:

- (void) setRequiresSecureCoding: (BOOL)requires;

Availability: MacOS-X 10.8.0

Description forthcoming.

systemVersion

- (unsigned int) systemVersion;

Availability: OpenStep

Returns *Step version, which is not the release version, but a large number, by specification <1000 for pre-OpenStep. This implementation returns a number based on the GNUstep major, minor, and subminor versions.

versionForClassName:

- (NSInteger) versionForClassName: (NSString*)className;

Availability: OpenStep

Returns current version of class (when encoding) or version of decoded class (decoded). Version comes from [NSObject -getVersion].