Saving and loading user data and preferences

#import <Foundation/Foundation.h>
 
@interface SettingsManager : NSObject {
	NSMutableDictionary* settings;
}
 
-(NSString *)getString:(NSString*)value;
-(int)getInt:(NSString*)value;
-(void)setValue:(NSString*)value newString:(NSString *)aValue;
-(void)setValue:(NSString*)value newInt:(int)aValue;
-(void)save;
-(void)load;
-(void)logSettings;
 
+(SettingsManager*)sharedSettingsManager;
@end

#import "SettingsManager.h"
 
@implementation SettingsManager
 
static SettingsManager* _sharedSettingsManager = nil;
 
-(NSString *)getString:(NSString*)value
{	
	return [settings objectForKey:value];
}
 
-(int)getInt:(NSString*)value {
	return [[settings objectForKey:value] intValue];
}
 
-(void)setValue:(NSString*)value newString:(NSString *)aValue {	
	[settings setObject:aValue forKey:value];
}
 
-(void)setValue:(NSString*)value newInt:(int)aValue {
	[settings setObject:[NSString stringWithFormat:@"%i",aValue] forKey:value];
}
 
-(void)save
{
        // NOTE: You should be replace "MyAppName" with your own custom application string.
        //
	[[NSUserDefaults standardUserDefaults] setObject:settings forKey:@"MyAppName"];
	[[NSUserDefaults standardUserDefaults] synchronize];	
}
 
-(void)load
{
        // NOTE: You should be replace "MyAppName" with your own custom application string.
        //
	[settings addEntriesFromDictionary:[[NSUserDefaults standardUserDefaults] objectForKey:@"MyAppName"]];
}
 
// Logging function great for checkin out what keys/values you have at any given time
//
-(void)logSettings
{
	for(NSString* item in [settings allKeys])
	{
		NSLog(@"[SettingsManager KEY:%@ - VALUE:%@]", item, [settings valueForKey:item]);
	}
}
 
+(SettingsManager*)sharedSettingsManager
{
	@synchronized([SettingsManager class])
	{
		if (!_sharedSettingsManager)
			[[self alloc] init];
 
		return _sharedSettingsManager;
	}
 
	return nil;
}
 
+(id)alloc
{
	@synchronized([SettingsManager class])
	{
		NSAssert(_sharedSettingsManager == nil, @"Attempted to allocate a second instance of a singleton.");
		_sharedSettingsManager = [[super alloc] init];
		return _sharedSettingsManager;
	}
 
	return nil;
}
 
-(id)autorelease {
    return self;
}
 
-(id)init {	
	settings = [[NSMutableDictionary alloc] initWithCapacity:5];	
	return [super init];
}
 
@end

[[SettingsManager sharedSettingsManager] saveValue:@"hiscore" newValue:@"10000"];
NSString* myValue = [[SettingsManager sharedSettingsManager] getValue:@"hiscore"];
int myInt = [[SettingsManager sharedSettingsManager] getInt:@"challenges_won"];

- (void)applicationDidFinishLaunching:(UIApplication *)application
 
{
  // ...  (some code) ...
 
  // Load settings on initial startup
  //
  [[SettingsManager sharedSettingsManager] load];
 
  // ...  (more code) ...
}
 
- (void)applicationWillResignActive:(UIApplication *)application
{
  [[SettingsManager sharedSettingsManager] save];
  [[Director sharedDirector] pause];
}
 
- (void)applicationDidBecomeActive:(UIApplication *)application
{
  [[SettingsManager sharedSettingsManager] load];
  [[Director sharedDirector] resume];
}
 
- (void)applicationWillTerminate:(UIApplication *)application
{
  [[SettingsManager sharedSettingsManager] save];
  [[Director sharedDirector] end];
}