iOS UUID library as alternative to the old good UDID and identifierForVendor.
This library provides the simplest API to obtain universally unique identifiers with different levels of persistence.

It's possible to retrieve the UUIDs created for all devices of the same user, in this way with a little bit of server-side help it's possible manage guest accounts across multiple devices easily.

##Requirements & dependencies

• iOS >= 5.0
• ARC enabled
• Key-value storage enabled (target / Capabilities / iCloud / Key-value storage)
• Security.framework
• UICKeyChainStore
• (optional) - KeyChain sharing enabled (entitlements and provisioning profile) if you need to share the same uuidForDevice / uuidsOfUserDevices values across multiple apps with the same bundle seed.

##Installation

####CocoaPods: pod 'FCUUID'

####Manual install:

• Copy FCUUID folder to your project.
• Manual install UICKeyChainStore

###Optional setup: It is recommended to do the setup in applicationDidFinishLaunchingWithOptions method.

• Add an observer to the FCUUIDsOfUserDevicesDidChangeNotification to be notified about uuids of user devices changes.
• If necessary, migrate from a previously used UUID or UDID using one of the migrations methods listed in the API section (it's recommended to do migration before calling uuidForDevice or uuidsForUserDevices methods). Keep in mind that migration works only if the existing value is a valid uuid and uuidForDevice has not been created yet.
• Call any class method to enforce iCloud sync.

##API Get different UUIDs (each one with its own persistency level)

//changes each time (no persistent)
+(NSString *)uuid;

//changes each time (no persistent), but allows to keep in memory more temporary uuids
+(NSString *)uuidForKey:(id<NSCopying>)key;

//changes each time the app gets launched (persistent to session)
+(NSString *)uuidForSession;

//changes each time the app gets installed (persistent to installation)
+(NSString *)uuidForInstallation;

//changes each time all the apps of the same vendor are uninstalled (this works exactly as identifierForVendor)
+(NSString *)uuidForVendor;

//changes only on system reset, this is the best replacement to the good old udid (persistent to device)
+(NSString *)uuidForDevice;
//or
#import "UIDevice+FCUUID.h"
[[UIDevice currentDevice] uuid];

Get the list of UUIDs of user devices

//returns the list of all uuidForDevice of the same user, in this way it's possible manage guest accounts across multiple devices easily
+(NSArray *)uuidsOfUserDevices;

Migrate from a previously stored UUID / UDID
Before migrating an existing value it's recommended to debug it by simply passing commitMigration:NO and logging the returned value.
When you will be ready for committing the migration, use commitMigration:YES.
After the migration, any future call to uuidForDevice will return the migrated value.

//these methods search for an existing UUID / UDID stored in the KeyChain or in UserDefaults for the given key / service / access-group
+(NSString *)uuidForDeviceMigratingValueForKey:(NSString *)key commitMigration:(BOOL)commitMigration;
+(NSString *)uuidForDeviceMigratingValueForKey:(NSString *)key service:(NSString *)service commitMigration:(BOOL)commitMigration;
+(NSString *)uuidForDeviceMigratingValueForKey:(NSString *)key service:(NSString *)service accessGroup:(NSString *)accessGroup commitMigration:(BOOL)commitMigration;

Check if value is a valid UUID

+(BOOL)uuidValueIsValid:(NSString *)uuidValue;

##Persistence

• √ yes
• - no
• * read notes below

*(persists only if the user have not uninstalled all apps of the same vendor)

**(persists only if the user restores a device backup which includes also keychain's data)

##Donate Do you want to support me?

##License The MIT License (MIT)

Copyright (c) 2015 Fabio Caccamo - [email protected]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.