NSObject-NSCoding

NSObject-NSCoding copied to clipboard

NSObject+NSCoding and Archiver

Mike Mayo Rackspace Mobile Apps [email protected] twitter: @greenisus

These are some simple classes to make object persistence with NSCoding easier. This code was extracted from the Rackspace Cloud / OpenStack iOS app at http://launchpad.net/openstack-ios

INSTALLATION

To install, simply drag Archiver.h, Archiver.m, NSObject+NSCoding.h, and NSObject+NSCoding.m into your project.

Then, right click Frameworks in Groups & Files and choose Add -> Existing Frameworks... and choose libobjc.A.dylib.

USAGE

-- Archiver

This class will read and write objects that conform to the NSCoding protocol to disk.

Archiver Usage:

SomeClass *myObject = [[[SomeClass alloc] init] autorelease]; myObject.someProperty = @"Hello world";

[Archiver persist:myObject key:@"myObject"];

// later on somewhere else...

SomeClass *myObject = [Archiver retrieve:@"myObject"];

-- NSObject+NSCoding

This category simplifies implementing NSCoding by iterating over the properties of your class and encoding/decoding them for you. It persists primitives (such as ints and floats) as well as any objects that conform to NSCoding.

NSObject+NSCoding Usage:

In your class header, conform to NSCoding:

@interface Model : NSObject <NSCoding> { //... }

In your class implementation, call the automatic methods:

• (void)encodeWithCoder:(NSCoder *)coder { [self autoEncodeWithCoder:coder]; }

• (id)initWithCoder:(NSCoder *)coder { if (self = [super init]) { [self autoDecode:coder]; } return self; }