iphone - 使用 -openWithBehavior :completionHandler: 获取 iOS 版 Facebook 应用的发布权限

Question

在我的应用程序中，我需要用户登录 Facebook，在我的表格 View 中获取 friend 列表并在提要上发布，但我不想将用户重定向到任何地方。所以我使用了 -openWithBehavior:completionHandler: ...这是我的代码。

-(IBAction)loginAction:(id)sender {
[self deleteCookies];
// get the app delegate so that we can access the session property
DLAppDelegate *appDelegate = [[UIApplication sharedApplication]delegate];

// this button's job is to flip-flop the session from open to closed
if (appDelegate.session.isOpen) {
    // if a user logs out explicitly, we delete any cached token information, and next
    // time they run the applicaiton they will be presented with log in UX again; most
    // users will simply close the app or switch away, without logging out; this will
    // cause the implicit cached-token login to occur on next launch of the application
    [appDelegate.session closeAndClearTokenInformation];

} else {
    if (appDelegate.session.state != FBSessionStateCreated) {
        // Create a new, logged out session.
        appDelegate.session = [[FBSession alloc] init];
        [self updateView];
    }

    // if the session isn't open, let's open it now and present the login UX to the user
    [appDelegate.session openWithBehavior:FBSessionLoginBehaviorForcingWebView completionHandler:^(FBSession *session, FBSessionState status, NSError *error) {
        switch (status) {
            case FBSessionStateOpen:
                // call the legacy session delegate
                //Now the session is open do corresponding UI changes
            {
                FBCacheDescriptor *cacheDescriptor = [FBFriendPickerViewController cacheDescriptor];
                [cacheDescriptor prefetchAndCacheForSession:session];
                [FBSession openActiveSessionWithAllowLoginUI:NO];
                [FBSession openActiveSessionWithPublishPermissions:[NSArray arrayWithObjects:@"publish_stream",@"publish_actions", nil] defaultAudience:FBSessionDefaultAudienceFriends allowLoginUI:NO completionHandler:nil];
            }
                break;
            case FBSessionStateClosedLoginFailed:
            { // prefer to keep decls near to their use                    
                // unpack the error code and reason in order to compute cancel bool
                // call the legacy session delegate if needed
                //[[delegate facebook] fbDialogNotLogin:userDidCancel];
            }
                break;
                // presently extension, log-out and invalidation are being implemented in the Facebook class
            default:
                break; // so we do nothing in response to those state transitions
        }
        [self updateView];
    }];
}
}

用户已成功登录，我可以使用 FQL 检索好友列表。问题是在发布到提要时。我知道我需要获得发布权限才能做到这一点。但是当我使用以下代码发布...

- (IBAction)postAction:(id)sender {
DLAppDelegate *appDelegate = [[UIApplication sharedApplication]delegate];
if (appDelegate.session.isOpen) {
    [FBSession openActiveSessionWithAllowLoginUI:NO];
    NSMutableDictionary *postParams = [[NSMutableDictionary alloc] initWithObjectsAndKeys:
                                       @"https://developers.facebook.com/ios", @"link",
                                       @"https://developers.facebook.com/attachment/iossdk_logo.png", @"picture",
                                       @"Facebook SDK for iOS", @"name",
                                       @"Build great social apps and get more installs.", @"caption",
                                       @"The Facebook SDK for iOS makes it easier and faster to develop Facebook integrated iOS apps.", @"description",
                                       nil];
    if ([_postText.text length]>0) {
        [postParams setObject:[_postText text] forKey:@"message"];
    }
    if (([FBSession.activeSession.permissions
          indexOfObject:@"publish_actions"] == NSNotFound) ||
        ([FBSession.activeSession.permissions
          indexOfObject:@"publish_stream"] == NSNotFound)) {

        // No permissions found in session, ask for it
        [FBSession.activeSession
         reauthorizeWithPublishPermissions:
         [NSArray arrayWithObjects:@"publish_stream",@"publish_actions",nil]
         defaultAudience:FBSessionDefaultAudienceFriends
         completionHandler:^(FBSession *session, NSError *error) {
             if (!error) {
                 // If permissions granted, publish the story
                 [self publishStory:postParams];
             }
         }];
    } else {
        // If permissions present, publish the story
        [self publishStory:postParams];
    }
}    
}

-(void)publishStory:(NSDictionary *)postParams {
[FBRequestConnection startWithGraphPath:
                             @"me/feed" parameters:postParams HTTPMethod:@"POST"
                      completionHandler:^(FBRequestConnection *connection, id result, NSError *error)
 {
     if (!error) {
         //Tell the user that it worked.
         UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Shared:"
                                                             message:[NSString stringWithFormat:@"Sucessfully posted to your wall."]
                                                            delegate:self
                                                   cancelButtonTitle:@"OK"
                                                   otherButtonTitles:nil];
         alertView.tag = 101;
         [alertView show];
     }
     else {
         UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Error:"
                                                             message:error.localizedDescription
                                                            delegate:nil
                                                   cancelButtonTitle:@"OK"
                                                   otherButtonTitles:nil];
         [alertView show];
         NSLog(@"%@",error);
     }
 }
 ];    
}

此代码将用户重定向到 Safari 或 Facebook 应用程序。这是我不想发生的。

当然我需要在登录时获得发布权限。问题是如何？

Answer 1

您必须设置 FBSessionLoginBehavior，要更改它，唯一的方法是使用:

[session openWithBehavior:FBSessionLoginBehaviorWithNoFallbackToWebView
    completionHandler:^(FBSession *session,
                        FBSessionState status,
                        NSError *error) {
        // Respond to session state changes, 
        // ex: updating the view
    }];

我看到你用 FBSessionLoginBehaviorForcingWebView ，所以要得到你想要的，你必须从这个枚举中选择:

typedef enum {
/*! 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,
} FBSessionLoginBehavior;

现在要解决这个“我肯定需要在登录时获得发布权限。问题是如何？”你可以 - (id)initWithPermissions:(NSArray*)permissions;您的 Session :

NSArray *permissions = @[@"publish_stream", @"publish_actions"];
appDelegate.session = [[FBSession alloc] initWithPermissions:permissions];