IOS7 App Development Essentials(3)NSUserDefaults

IOS7 App Development Essentials(3)NSUserDefaults

In Android world, we have SharedPreferences, in iOS world, we should use NSUserDetails.

The NSUserDefaults class provides a interface for interacting with the defaults system.

Applications record such preferences by assigning values to a set of parameters in a user’s defaults databases. NSUserDefaults caches the information to avoid having to open the user’s defaults database.

It will support these classes
NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary

It support NSDictionary.

Here is How I use NSUserDefaults

Define the interface
@interface SLUserDefaults : NSObject + (NSDictionary *)getBeaconDataDictionary; + (void)setBeaconDataDictionary:(NSDictionary *)beacons;

+(void)setBeaconRangingOutside:(NSString *)identifier; +(NSString *)getBeaconRangingOutside;

+ (void)setBeaconRangingBeacons:(NSSet *)beacons; + (NSSet *)getBeaconRangingBeacons;

+ (BOOL)isBeaconRangeRunning; + (void)setBeaconRangeRunning:(BOOL) status;

Here is the implementation
#import “SLUserDefaults.h"staticNSString *const DEVICE_REGISTERED_KEY = @“SL_isRegistered"; staticNSString *const IS_STARTED_KEY = @“SL_isStarted";

@implementation LPUserDefaults

+ (NSDictionary *)getBeaconDataDictionary{    @synchronized(self){        if([[NSUserDefaultsstandardUserDefaults] objectForKey:BEACON_DATA_DIC]){            return [NSKeyedUnarchiverunarchiveObjectWithData:[[NSUserDefaultsstandardUserDefaults] objectForKey:BEACON_DATA_DIC]];        }else{            return [[NSDictionaryalloc] init];        }    } } + (void)setBeaconDataDictionary:(NSDictionary *)beacons {    @synchronized(self){        if(beacons != nil && [beacons count] > 0){            NSData *encodedObjects = [NSKeyedArchiverarchivedDataWithRootObject:beacons];            [[NSUserDefaultsstandardUserDefaults] setObject:encodedObjects forKey:BEACON_DATA_DIC];        }    } }

+ (void)setBeaconDataDictionary:(NSDictionary *)beacons {    @synchronized(self){        if(beacons != nil && [beacons count] > 0){            NSData *encodedObjects = [NSKeyedArchiverarchivedDataWithRootObject:beacons];            [[NSUserDefaultsstandardUserDefaults] setObject:encodedObjects forKey:BEACON_DATA_DIC];        }    } } +(void)setBeaconRangingOutside:(NSString *)identifier{    @synchronized(self){        [[NSUserDefaultsstandardUserDefaults] setValue:identifier forKey:BEACON_RANGING_OUTSIDE];    } }

+ (void)setBeaconMonitoringBeacons:(NSSet *)beacons {    @synchronized(self){        if(beacons != nil && [beacons count] > 0){            NSData *encodedObjects = [NSKeyedArchiverarchivedDataWithRootObject:beacons];            [[NSUserDefaultsstandardUserDefaults] setObject:encodedObjects forKey:BEACON_MONITORING_BEACONS];        }    } } + (NSSet *)getBeaconMonitoringBeacons{    @synchronized(self){        if([[NSUserDefaultsstandardUserDefaults] objectForKey:BEACON_MONITORING_BEACONS]){            return [NSKeyedUnarchiverunarchiveObjectWithData:[[NSUserDefaultsstandardUserDefaults] objectForKey:BEACON_MONITORING_BEACONS]];        }else{            return [[NSSetalloc] init ];        }    } }

+ (BOOL)isRegistered {    @synchronized(self) {        return [[NSUserDefaultsstandardUserDefaults] boolForKey:DEVICE_REGISTERED_KEY];    } } + (void)setRegistered {    @synchronized(self) {        [[NSUserDefaultsstandardUserDefaults] setBool:YESforKey:DEVICE_REGISTERED_KEY];    } }


References:
http://sillycat.iteye.com/blog/1841920

Store Object
http://stackoverflow.com/questions/2315948/how-to-store-custom-objects-in-nsuserdefaults