/* * Copyright 2010-present Facebook. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #import #import #import "FBSDKMacros.h" // up-front decl's @class FBAccessTokenData; @class FBSession; @class FBSessionTokenCachingStrategy; #define FB_SESSIONSTATETERMINALBIT (1 << 8) #define FB_SESSIONSTATEOPENBIT (1 << 9) /* * Constants used by NSNotificationCenter for active session notification */ /*! NSNotificationCenter name indicating that a new active session was set */ FBSDK_EXTERN NSString *const FBSessionDidSetActiveSessionNotification; /*! NSNotificationCenter name indicating that an active session was unset */ FBSDK_EXTERN NSString *const FBSessionDidUnsetActiveSessionNotification; /*! NSNotificationCenter name indicating that the active session is open */ FBSDK_EXTERN NSString *const FBSessionDidBecomeOpenActiveSessionNotification; /*! NSNotificationCenter name indicating that there is no longer an open active session */ FBSDK_EXTERN NSString *const FBSessionDidBecomeClosedActiveSessionNotification; /*! @typedef FBSessionState enum @abstract Passed to handler block each time a session state changes @discussion A typical `FBSession` lifecycle will start with `FBSessionStateCreated`. If a cached token is available, it will transition to `FBSessionStateCreatedTokenLoaded`. When attempting to open a session, it will become `FBSessionStateCreatedOpening` internally before going to `FBSessionStateOpen` or `FBSessionStateClosedLoginFailed`. From `FBSessionStateOpen` it can go to `FBSessionStateOpenTokenExtended` (when more permissions were granted) or `FBSessionStateClosed`. */ typedef NS_ENUM(NSUInteger, FBSessionState) { /*! One of two initial states indicating that no valid cached token was found */ FBSessionStateCreated = 0, /*! One of two initial session states indicating that a cached token was loaded; when a session is in this state, a call to open* will result in an open session, without UX or app-switching*/ FBSessionStateCreatedTokenLoaded = 1, /*! One of three pre-open session states indicating that an attempt to open the session is underway*/ FBSessionStateCreatedOpening = 2, /*! Open session state indicating user has logged in or a cached token is available */ FBSessionStateOpen = 1 | FB_SESSIONSTATEOPENBIT, /*! Open session state indicating token has been extended, or the user has granted additional permissions */ FBSessionStateOpenTokenExtended = 2 | FB_SESSIONSTATEOPENBIT, /*! Closed session state indicating that a login attempt failed */ FBSessionStateClosedLoginFailed = 1 | FB_SESSIONSTATETERMINALBIT, // NSError obj w/more info /*! Closed session state indicating that the session was closed, but the users token remains cached on the device for later use */ FBSessionStateClosed = 2 | FB_SESSIONSTATETERMINALBIT, // " }; /*! helper macro to test for states that imply an open session */ #define FB_ISSESSIONOPENWITHSTATE(state) (0 != (state & FB_SESSIONSTATEOPENBIT)) /*! helper macro to test for states that are terminal */ #define FB_ISSESSIONSTATETERMINAL(state) (0 != (state & FB_SESSIONSTATETERMINALBIT)) /*! @typedef FBSessionLoginBehavior enum @abstract Passed to open to indicate whether Facebook Login should allow for fallback to be attempted. @discussion Facebook Login authorizes the application to act on behalf of the user, using the user's Facebook account. Usually a Facebook Login will rely on an account maintained outside of the application, by the native Facebook application, the browser, or perhaps the device itself. This avoids the need for a user to enter their username and password directly, and provides the most secure and lowest friction way for a user to authorize the application to interact with Facebook. If a Facebook Login is not possible, a fallback Facebook Login may be attempted, where the user is prompted to enter their credentials in a web-view hosted directly by the application. The `FBSessionLoginBehavior` enum specifies whether to allow fallback, disallow fallback, or force fallback login behavior. Most applications will use the default, which attempts a normal Facebook Login, and only falls back if needed. In rare cases, it may be preferable to disallow fallback Facebook Login completely, or to force a fallback login. */ typedef NS_ENUM(NSUInteger, FBSessionLoginBehavior) { /*! Attempt Facebook Login, ask user for credentials if necessary */ FBSessionLoginBehaviorWithFallbackToWebView = 0, /*! Attempt Facebook Login, no direct request for credentials will be made */ FBSessionLoginBehaviorWithNoFallbackToWebView = 1, /*! Only attempt WebView Login; ask user for credentials */ FBSessionLoginBehaviorForcingWebView = 2, /*! Attempt Facebook Login, prefering system account and falling back to fast app switch if necessary */ FBSessionLoginBehaviorUseSystemAccountIfPresent = 3, /*! Attempt only to login with Safari */ FBSessionLoginBehaviorForcingSafari = 4, }; /*! @typedef FBSessionDefaultAudience enum @abstract Passed to open to indicate which default audience to use for sessions that post data to Facebook. @discussion Certain operations such as publishing a status or publishing a photo require an audience. When the user grants an application permission to perform a publish operation, a default audience is selected as the publication ceiling for the application. This enumerated value allows the application to select which audience to ask the user to grant publish permission for. */ typedef NS_ENUM(NSUInteger, FBSessionDefaultAudience) { /*! No audience needed; this value is useful for cases where data will only be read from Facebook */ FBSessionDefaultAudienceNone = 0, /*! Indicates that only the user is able to see posts made by the application */ FBSessionDefaultAudienceOnlyMe = 10, /*! Indicates that the user's friends are able to see posts made by the application */ FBSessionDefaultAudienceFriends = 20, /*! Indicates that all Facebook users are able to see posts made by the application */ FBSessionDefaultAudienceEveryone = 30, }; /*! @typedef FBSessionLoginType enum @abstract Used as the type of the loginType property in order to specify what underlying technology was used to login the user. @discussion The FBSession object is an abstraction over five distinct mechanisms. This enum allows an application to test for the mechanism used by a particular instance of FBSession. Usually the mechanism used for a given login does not matter, however for certain capabilities, the type of login can impact the behavior of other Facebook functionality. */ typedef NS_ENUM(NSUInteger, FBSessionLoginType) { /*! A login type has not yet been established */ FBSessionLoginTypeNone = 0, /*! A system integrated account was used to log the user into the application */ FBSessionLoginTypeSystemAccount = 1, /*! The Facebook native application was used to log the user into the application */ FBSessionLoginTypeFacebookApplication = 2, /*! Safari was used to log the user into the application */ FBSessionLoginTypeFacebookViaSafari = 3, /*! A web view was used to log the user into the application */ FBSessionLoginTypeWebView = 4, /*! A test user was used to create an open session */ FBSessionLoginTypeTestUser = 5, }; /*! @typedef @abstract Block type used to define blocks called by for state updates @discussion See https://developers.facebook.com/docs/technical-guides/iossdk/errors/ for error handling best practices. Requesting additional permissions inside this handler (such as by calling `requestNewPublishPermissions`) should be avoided because it is a poor user experience and its behavior may vary depending on the login type. You should request the permissions closer to the operation that requires it (e.g., when the user performs some action). */ typedef void (^FBSessionStateHandler)(FBSession *session, FBSessionState status, NSError *error); /*! @typedef @abstract Block type used to define blocks called by <[FBSession requestNewReadPermissions:completionHandler:]> and <[FBSession requestNewPublishPermissions:defaultAudience:completionHandler:]>. @discussion See https://developers.facebook.com/docs/technical-guides/iossdk/errors/ for error handling best practices. Requesting additional permissions inside this handler (such as by calling `requestNewPublishPermissions`) should be avoided because it is a poor user experience and its behavior may vary depending on the login type. You should request the permissions closer to the operation that requires it (e.g., when the user performs some action). */ typedef void (^FBSessionRequestPermissionResultHandler)(FBSession *session, NSError *error); /*! @typedef @abstract Block type used to define blocks called by <[FBSession reauthorizeWithPermissions]>. @discussion You should use the preferred FBSessionRequestPermissionHandler typedef rather than this synonym, which has been deprecated. */ typedef FBSessionRequestPermissionResultHandler FBSessionReauthorizeResultHandler __attribute__((deprecated)); /*! @typedef @abstract Block type used to define blocks called for system credential renewals. */ typedef void (^FBSessionRenewSystemCredentialsHandler)(ACAccountCredentialRenewResult result, NSError *error) ; /*! @class FBSession @abstract The `FBSession` object is used to authenticate a user and manage the user's session. After initializing a `FBSession` object the Facebook App ID and desired permissions are stored. Opening the session will initiate the authentication flow after which a valid user session should be available and subsequently cached. Closing the session can optionally clear the cache. If an request requires user authorization then an `FBSession` object should be used. @discussion Instances of the `FBSession` class provide notification of state changes in the following ways: 1. Callers of certain `FBSession` methods may provide a block that will be called back in the course of state transitions for the session (e.g. login or session closed). 2. The object supports Key-Value Observing (KVO) for property changes. */ @interface FBSession : NSObject /*! @methodgroup Creating a session */ /*! @method @abstract Returns a newly initialized Facebook session with default values for the parameters to . */ - (instancetype)init; /*! @method @abstract Returns a newly initialized Facebook session with the specified permissions and other default values for parameters to . @param permissions An array of strings representing the permissions to request during the authentication flow. @discussion It is required that any single permission request request (including initial log in) represent read-only permissions or publish permissions only; not both. The permissions passed here should reflect this requirement. */ - (instancetype)initWithPermissions:(NSArray *)permissions; /*! @method @abstract Following are the descriptions of the arguments along with their defaults when ommitted. @param permissions An array of strings representing the permissions to request during the authentication flow. @param appID The Facebook App ID for the session. If nil is passed in the default App ID will be obtained from a call to <[FBSession defaultAppID]>. The default is nil. @param urlSchemeSuffix The URL Scheme Suffix to be used in scenarious where multiple iOS apps use one Facebook App ID. A value of nil indicates that this information should be pulled from [FBSettings defaultUrlSchemeSuffix]. The default is nil. @param tokenCachingStrategy Specifies a key name to use for cached token information in NSUserDefaults, nil indicates a default value of @"FBAccessTokenInformationKey". @discussion It is required that any single permission request request (including initial log in) represent read-only permissions or publish permissions only; not both. The permissions passed here should reflect this requirement. */ - (instancetype)initWithAppID:(NSString *)appID permissions:(NSArray *)permissions urlSchemeSuffix:(NSString *)urlSchemeSuffix tokenCacheStrategy:(FBSessionTokenCachingStrategy *)tokenCachingStrategy; /*! @method @abstract Following are the descriptions of the arguments along with their defaults when ommitted. @param permissions An array of strings representing the permissions to request during the authentication flow. @param defaultAudience Most applications use FBSessionDefaultAudienceNone here, only specifying an audience when using reauthorize to request publish permissions. @param appID The Facebook App ID for the session. If nil is passed in the default App ID will be obtained from a call to <[FBSession defaultAppID]>. The default is nil. @param urlSchemeSuffix The URL Scheme Suffix to be used in scenarious where multiple iOS apps use one Facebook App ID. A value of nil indicates that this information should be pulled from [FBSettings defaultUrlSchemeSuffix]. The default is nil. @param tokenCachingStrategy Specifies a key name to use for cached token information in NSUserDefaults, nil indicates a default value of @"FBAccessTokenInformationKey". @discussion It is required that any single permission request request (including initial log in) represent read-only permissions or publish permissions only; not both. The permissions passed here should reflect this requirement. If publish permissions are used, then the audience must also be specified. */ - (instancetype)initWithAppID:(NSString *)appID permissions:(NSArray *)permissions defaultAudience:(FBSessionDefaultAudience)defaultAudience urlSchemeSuffix:(NSString *)urlSchemeSuffix tokenCacheStrategy:(FBSessionTokenCachingStrategy *)tokenCachingStrategy; // instance readonly properties /*! @abstract Indicates whether the session is open and ready for use. */ @property (readonly) BOOL isOpen; /*! @abstract Detailed session state */ @property (readonly) FBSessionState state; /*! @abstract Identifies the Facebook app which the session object represents. */ @property (readonly, copy) NSString *appID; /*! @abstract Identifies the URL Scheme Suffix used by the session. This is used when multiple iOS apps share a single Facebook app ID. */ @property (readonly, copy) NSString *urlSchemeSuffix; /*! @abstract The access token for the session object. @discussion Deprecated. Use the `accessTokenData` property. */ @property(readonly, copy) NSString *accessToken __attribute__((deprecated)); /*! @abstract The expiration date of the access token for the session object. @discussion Deprecated. Use the `accessTokenData` property. */ @property(readonly, copy) NSDate *expirationDate __attribute__((deprecated)); /*! @abstract The permissions granted to the access token during the authentication flow. */ @property (readonly, copy) NSArray *permissions; /*! @abstract Specifies the login type used to authenticate the user. @discussion Deprecated. Use the `accessTokenData` property. */ @property(readonly) FBSessionLoginType loginType __attribute__((deprecated)); /*! @abstract Gets the FBAccessTokenData for the session */ @property (readonly, copy) FBAccessTokenData *accessTokenData; /*! @abstract Returns a collection of permissions that have been declined by the user for this given session instance. @discussion A "declined" permission is one that had been requested but was either skipped or removed by the user during the login flow. Note that once the permission has been granted (either by requesting again or detected by a permissions refresh), it will be removed from this collection. */ @property (readonly, copy) NSArray *declinedPermissions; /*! @methodgroup Instance methods */ /*! @method @abstract Opens a session for the Facebook. @discussion A session may not be used with and other classes in the SDK until it is open. If, prior to calling open, the session is in the state, then no UX occurs, and the session becomes available for use. If the session is in the state, prior to calling open, then a call to open causes login UX to occur, either via the Facebook application or via mobile Safari. Open may be called at most once and must be called after the `FBSession` is initialized. Open must be called before the session is closed. Calling an open method at an invalid time will result in an exception. The open session methods may be passed a block that will be called back when the session state changes. The block will be released when the session is closed. @param handler A block to call with the state changes. The default is nil. */ - (void)openWithCompletionHandler:(FBSessionStateHandler)handler; /*! @method @abstract Logs a user on to Facebook. @discussion A session may not be used with and other classes in the SDK until it is open. If, prior to calling open, the session is in the state, then no UX occurs, and the session becomes available for use. If the session is in the state, prior to calling open, then a call to open causes login UX to occur, either via the Facebook application or via mobile Safari. The method may be called at most once and must be called after the `FBSession` is initialized. It must be called before the session is closed. Calling the method at an invalid time will result in an exception. The open session methods may be passed a block that will be called back when the session state changes. The block will be released when the session is closed. @param behavior Controls whether to allow, force, or prohibit Facebook Login or Inline Facebook Login. The default is to allow Facebook Login, with fallback to Inline Facebook Login. @param handler A block to call with session state changes. The default is nil. */ - (void)openWithBehavior:(FBSessionLoginBehavior)behavior completionHandler:(FBSessionStateHandler)handler; /*! @method @abstract Imports an existing access token and opens the session with it. @discussion The method attempts to open the session using an existing access token. No UX will occur. If successful, the session with be in an Open state and the method will return YES; otherwise, NO. The method may be called at most once and must be called after the `FBSession` is initialized (see below). It must be called before the session is closed. Calling the method at an invalid time will result in an exception. The open session methods may be passed a block that will be called back when the session state changes. The block will be released when the session is closed. The initialized session must not have already been initialized from a cache (for example, you could use the `[FBSessionTokenCachingStrategy nullCacheInstance]` instance). @param accessTokenData The token data. See `FBAccessTokenData` for construction methods. @param handler A block to call with session state changes. The default is nil. */ - (BOOL)openFromAccessTokenData:(FBAccessTokenData *)accessTokenData completionHandler:(FBSessionStateHandler) handler; /*! @abstract Closes the local in-memory session object, but does not clear the persisted token cache. */ - (void)close; /*! @abstract Closes the in-memory session, and clears any persisted cache related to the session. */ - (void)closeAndClearTokenInformation; /*! @abstract Reauthorizes the session, with additional permissions. @param permissions An array of strings representing the permissions to request during the authentication flow. A value of nil indicates basic permissions. The default is nil. @param behavior Controls whether to allow, force, or prohibit Facebook Login. The default is to allow Facebook Login and fall back to Inline Facebook Login if needed. @param handler A block to call with session state changes. The default is nil. @discussion Methods and properties that specify permissions without a read or publish qualification are deprecated; use of a read-qualified or publish-qualified alternative is preferred (e.g. reauthorizeWithReadPermissions or reauthorizeWithPublishPermissions) */ - (void)reauthorizeWithPermissions:(NSArray *)permissions behavior:(FBSessionLoginBehavior)behavior completionHandler:(FBSessionReauthorizeResultHandler)handler __attribute__((deprecated)); /*! @abstract Reauthorizes the session, with additional permissions. @param readPermissions An array of strings representing the permissions to request during the authentication flow. A value of nil indicates basic permissions. @param handler A block to call with session state changes. The default is nil. @discussion This method is a deprecated alias of <[FBSession requestNewReadPermissions:completionHandler:]>. Consider using <[FBSession requestNewReadPermissions:completionHandler:]>, which is preferred for readability. */ - (void)reauthorizeWithReadPermissions:(NSArray *)readPermissions completionHandler:(FBSessionReauthorizeResultHandler)handler __attribute__((deprecated)); /*! @abstract Reauthorizes the session, with additional permissions. @param writePermissions An array of strings representing the permissions to request during the authentication flow. @param defaultAudience Specifies the audience for posts. @param handler A block to call with session state changes. The default is nil. @discussion This method is a deprecated alias of <[FBSession requestNewPublishPermissions:defaultAudience:completionHandler:]>. Consider using <[FBSession requestNewPublishPermissions:defaultAudience:completionHandler:]>, which is preferred for readability. */ - (void)reauthorizeWithPublishPermissions:(NSArray *)writePermissions defaultAudience:(FBSessionDefaultAudience)defaultAudience completionHandler:(FBSessionReauthorizeResultHandler)handler __attribute__((deprecated)); /*! @abstract Requests new or additional read permissions for the session. @param readPermissions An array of strings representing the permissions to request during the authentication flow. A value of nil indicates basic permissions. @param handler A block to call with session state changes. The default is nil. @discussion The handler, if non-nil, is called once the operation has completed or failed. This is in contrast to the state completion handler used in <[FBSession openWithCompletionHandler:]> (and other `open*` methods) which is called for each state-change for the session. */ - (void)requestNewReadPermissions:(NSArray *)readPermissions completionHandler:(FBSessionRequestPermissionResultHandler)handler; /*! @abstract Requests new or additional write permissions for the session. @param writePermissions An array of strings representing the permissions to request during the authentication flow. @param defaultAudience Specifies the audience for posts. @param handler A block to call with session state changes. The default is nil. @discussion The handler, if non-nil, is called once the operation has completed or failed. This is in contrast to the state completion handler used in <[FBSession openWithCompletionHandler:]> (and other `open*` methods) which is called for each state-change for the session. */ - (void)requestNewPublishPermissions:(NSArray *)writePermissions defaultAudience:(FBSessionDefaultAudience)defaultAudience completionHandler:(FBSessionRequestPermissionResultHandler)handler; /*! @abstract Refreshes the current permissions for the session. @param handler Called after completion of the refresh. @discussion This will update the sessions' permissions array from the server. This can be useful if you want to make sure the local permissions are up to date. */ - (void)refreshPermissionsWithCompletionHandler:(FBSessionRequestPermissionResultHandler)handler; /*! @abstract A helper method that is used to provide an implementation for [UIApplicationDelegate application:openURL:sourceApplication:annotation:]. It should be invoked during the Facebook Login flow and will update the session information based on the incoming URL. @param url The URL as passed to [UIApplicationDelegate application:openURL:sourceApplication:annotation:]. */ - (BOOL)handleOpenURL:(NSURL *)url; /*! @abstract A helper method that is used to provide an implementation for [UIApplicationDelegate applicationDidBecomeActive:] to properly resolve session state for the Facebook Login flow, specifically to support app-switch login. */ - (void)handleDidBecomeActive; /*! @abstract Assign the block to be invoked for session state changes. @param stateChangeHandler the handler block. @discussion This will overwrite any state change handler that was already assigned. Typically, you should only use this setter if you were unable to assign a state change handler explicitly. One example of this is if you are not opening the session (e.g., using the `open*`) but still want to assign a `FBSessionStateHandler` block. This can happen when the SDK opens a session from an app link. */ - (void)setStateChangeHandler:(FBSessionStateHandler)stateChangeHandler; /*! @abstract Returns true if the specified permission has been granted to this session. @param permission the permission to verify. @discussion This is a convenience helper for checking if `pemission` is inside the permissions array. */ - (BOOL)hasGranted:(NSString *)permission; /*! @methodgroup Class methods */ /*! @abstract This is the simplest method for opening a session with Facebook. Using sessionOpen logs on a user, and sets the static activeSession which becomes the default session object for any Facebook UI widgets used by the application. This session becomes the active session, whether open succeeds or fails. Note, if there is not a cached token available, this method will present UI to the user in order to open the session via explicit login by the user. @param allowLoginUI Sometimes it is useful to attempt to open a session, but only if no login UI will be required to accomplish the operation. For example, at application startup it may not be disirable to transition to login UI for the user, and yet an open session is desired so long as a cached token can be used to open the session. Passing NO to this argument, assures the method will not present UI to the user in order to open the session. @discussion Returns YES if the session was opened synchronously without presenting UI to the user. This occurs when there is a cached token available from a previous run of the application. If NO is returned, this indicates that the session was not immediately opened, via cache. However, if YES was passed as allowLoginUI, then it is possible that the user will login, and the session will become open asynchronously. The primary use for this return value is to switch-on facebook capabilities in your UX upon startup, in the case where the session is opened via cache. */ + (BOOL)openActiveSessionWithAllowLoginUI:(BOOL)allowLoginUI; /*! @abstract This is a simple method for opening a session with Facebook. Using sessionOpen logs on a user, and sets the static activeSession which becomes the default session object for any Facebook UI widgets used by the application. This session becomes the active session, whether open succeeds or fails. @param permissions An array of strings representing the permissions to request during the authentication flow. A value of nil indicates basic permissions. A nil value specifies default permissions. @param allowLoginUI Sometimes it is useful to attempt to open a session, but only if no login UI will be required to accomplish the operation. For example, at application startup it may not be desirable to transition to login UI for the user, and yet an open session is desired so long as a cached token can be used to open the session. Passing NO to this argument, assures the method will not present UI to the user in order to open the session. @param handler Many applications will benefit from notification when a session becomes invalid or undergoes other state transitions. If a block is provided, the FBSession object will call the block each time the session changes state. @discussion Returns true if the session was opened synchronously without presenting UI to the user. This occurs when there is a cached token available from a previous run of the application. If NO is returned, this indicates that the session was not immediately opened, via cache. However, if YES was passed as allowLoginUI, then it is possible that the user will login, and the session will become open asynchronously. The primary use for this return value is to switch-on facebook capabilities in your UX upon startup, in the case where the session is opened via cache. It is required that initial permissions requests represent read-only permissions only. If publish permissions are needed, you may use reauthorizeWithPermissions to specify additional permissions as well as an audience. Use of this method will result in a legacy fast-app-switch Facebook Login due to the requirement to separate read and publish permissions for newer applications. Methods and properties that specify permissions without a read or publish qualification are deprecated; use of a read-qualified or publish-qualified alternative is preferred. */ + (BOOL)openActiveSessionWithPermissions:(NSArray *)permissions allowLoginUI:(BOOL)allowLoginUI completionHandler:(FBSessionStateHandler)handler __attribute__((deprecated)); /*! @abstract This is a simple method for opening a session with Facebook. Using sessionOpen logs on a user, and sets the static activeSession which becomes the default session object for any Facebook UI widgets used by the application. This session becomes the active session, whether open succeeds or fails. @param readPermissions An array of strings representing the read permissions to request during the authentication flow. It is not allowed to pass publish permissions to this method. @param allowLoginUI Sometimes it is useful to attempt to open a session, but only if no login UI will be required to accomplish the operation. For example, at application startup it may not be desirable to transition to login UI for the user, and yet an open session is desired so long as a cached token can be used to open the session. Passing NO to this argument, assures the method will not present UI to the user in order to open the session. @param handler Many applications will benefit from notification when a session becomes invalid or undergoes other state transitions. If a block is provided, the FBSession object will call the block each time the session changes state. @discussion Returns true if the session was opened synchronously without presenting UI to the user. This occurs when there is a cached token available from a previous run of the application. If NO is returned, this indicates that the session was not immediately opened, via cache. However, if YES was passed as allowLoginUI, then it is possible that the user will login, and the session will become open asynchronously. The primary use for this return value is to switch-on facebook capabilities in your UX upon startup, in the case where the session is opened via cache. */ + (BOOL)openActiveSessionWithReadPermissions:(NSArray *)readPermissions allowLoginUI:(BOOL)allowLoginUI completionHandler:(FBSessionStateHandler)handler; /*! @abstract This is a simple method for opening a session with Facebook. Using sessionOpen logs on a user, and sets the static activeSession which becomes the default session object for any Facebook UI widgets used by the application. This session becomes the active session, whether open succeeds or fails. @param publishPermissions An array of strings representing the publish permissions to request during the authentication flow. @param defaultAudience Anytime an app publishes on behalf of a user, the post must have an audience (e.g. me, my friends, etc.) The default audience is used to notify the user of the cieling that the user agrees to grant to the app for the provided permissions. @param allowLoginUI Sometimes it is useful to attempt to open a session, but only if no login UI will be required to accomplish the operation. For example, at application startup it may not be desirable to transition to login UI for the user, and yet an open session is desired so long as a cached token can be used to open the session. Passing NO to this argument, assures the method will not present UI to the user in order to open the session. @param handler Many applications will benefit from notification when a session becomes invalid or undergoes other state transitions. If a block is provided, the FBSession object will call the block each time the session changes state. @discussion Returns true if the session was opened synchronously without presenting UI to the user. This occurs when there is a cached token available from a previous run of the application. If NO is returned, this indicates that the session was not immediately opened, via cache. However, if YES was passed as allowLoginUI, then it is possible that the user will login, and the session will become open asynchronously. The primary use for this return value is to switch-on facebook capabilities in your UX upon startup, in the case where the session is opened via cache. */ + (BOOL)openActiveSessionWithPublishPermissions:(NSArray *)publishPermissions defaultAudience:(FBSessionDefaultAudience)defaultAudience allowLoginUI:(BOOL)allowLoginUI completionHandler:(FBSessionStateHandler)handler; /*! @abstract An application may get or set the current active session. Certain high-level components in the SDK will use the activeSession to set default session (e.g. `FBLoginView`, `FBFriendPickerViewController`) @discussion If sessionOpen* is called, the resulting `FBSession` object also becomes the activeSession. If another session was active at the time, it is closed automatically. If activeSession is called when no session is active, a session object is instatiated and returned; in this case open must be called on the session in order for it to be useable for communication with Facebook. */ + (FBSession *)activeSession; /*! @abstract An application may get or set the current active session. Certain high-level components in the SDK will use the activeSession to set default session (e.g. `FBLoginView`, `FBFriendPickerViewController`) @param session The FBSession object to become the active session @discussion If an application prefers the flexibilility of directly instantiating a session object, an active session can be set directly. */ + (FBSession *)setActiveSession:(FBSession *)session; /*! @method @abstract Set the default Facebook App ID to use for sessions. The app ID may be overridden on a per session basis. @discussion This method has been deprecated in favor of [FBSettings setDefaultAppID]. @param appID The default Facebook App ID to use for methods. */ + (void)setDefaultAppID:(NSString *)appID __attribute__((deprecated)); /*! @method @abstract Get the default Facebook App ID to use for sessions. If not explicitly set, the default will be read from the application's plist. The app ID may be overridden on a per session basis. @discussion This method has been deprecated in favor of [FBSettings defaultAppID]. */ + (NSString *)defaultAppID __attribute__((deprecated)); /*! @method @abstract Set the default url scheme suffix to use for sessions. The url scheme suffix may be overridden on a per session basis. @discussion This method has been deprecated in favor of [FBSettings setDefaultUrlSchemeSuffix]. @param urlSchemeSuffix The default url scheme suffix to use for methods. */ + (void)setDefaultUrlSchemeSuffix:(NSString *)urlSchemeSuffix __attribute__((deprecated)); /*! @method @abstract Get the default url scheme suffix used for sessions. If not explicitly set, the default will be read from the application's plist. The url scheme suffix may be overridden on a per session basis. @discussion This method has been deprecated in favor of [FBSettings defaultUrlSchemeSuffix]. */ + (NSString *)defaultUrlSchemeSuffix __attribute__((deprecated)); /*! @method @abstract Issues an asychronous renewCredentialsForAccount call to the device Facebook account store. @param handler The completion handler to call when the renewal is completed. The handler will be invoked on the main thread. @discussion This can be used to explicitly renew account credentials on iOS 6 devices and is provided as a convenience wrapper around `[ACAccountStore renewCredentialsForAccount:completion]`. Note the method will not issue the renewal call if the the Facebook account has not been set on the device, or if access had not been granted to the account (though the handler wil receive an error). This is safe to call (and will surface an error to the handler) on versions of iOS before 6 or if the user logged in via Safari or Facebook SSO. */ + (void)renewSystemCredentials:(FBSessionRenewSystemCredentialsHandler)handler; @end