PFAnonymousUtils.h

//
//  PFAnonymousUtils.h
//  Parse
//
//  Created by David Poll on 3/20/12.
//  Copyright (c) 2012 Parse, Inc. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "PFUser.h"
#import "PFConstants.h"

/*!
 Provides utility functions for working with Anonymously logged-in users.  Anonymous users have some unique characteristics:
 <ul>
   <li>Anonymous users don't need a user name or password.</li>
   <li>Once logged out, an anonymous user cannot be recovered.</li>
   <li>When the current user is anonymous, the following methods can be used to switch to a different user or convert the
     anonymous user into a regular one:
     <ul>
       <li>signUp converts an anonymous user to a standard user with the given username and password.
           Data associated with the anonymous user is retained.</li>
       <li>logIn switches users without converting the anonymous user.  Data associated with the anonymous user will be lost.</li>
       <li>Service logIn (e.g. Facebook, Twitter) will attempt to convert the anonymous user into a standard user by linking it to the service.
           If a user already exists that is linked to the service, it will instead switch to the existing user.</li>
       <li>Service linking (e.g. Facebook, Twitter) will convert the anonymous user into a standard user by linking it to the service.</li>
     </ul>
 </ul>
 */
@interface PFAnonymousUtils : NSObject

/*! @name Creating an Anonymous User */

/*!
 Creates an anonymous user.
 @param block The block to execute when anonymous user creation is complete. The block should have the following argument signature:
 (PFUser *user, NSError *error) 
 */
+ (void)logInWithBlock:(PFUserResultBlock)block;

/*!
 Creates an anonymous user.  The selector for the callback should look like: (PFUser *)user error:(NSError *)error
 @param target Target object for the selector.
 @param selector The selector that will be called when the asynchronous request is complete.
 */
+ (void)logInWithTarget:(id)target selector:(SEL)selector;

/*! @name Determining Whether a PFUser is Anonymous */

/*!
 Whether the user is logged in anonymously.
 @param user User to check for anonymity. The user must be logged in on this device.
 @result True if the user is anonymous.  False if the user is not the current user or is not anonymous.
 */
+ (BOOL)isLinkedWithUser:(PFUser *)user;

@end