Question

I am using this code to share an item on Facebook newsfeed:

-(void)recommendOnFacebook:(Item *)currentItem{    
if(!facebook){
    facebook = [[Facebook alloc] initWithAppId:@"myappid" andDelegate:self];
} 
NSMutableDictionary *params2 = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                [NSString stringWithFormat:@"%@", currentItem.name], @"name",
                                [shop name], @"caption",
                                currentItem.description, @"description",
                                [NSString stringWithFormat:@""], @"link",
                                currentItem.imagePath, @"picture",
                                nil, @"actions",
                                nil];    
[facebook dialog:@"feed" 
     andParams:params2
     andDelegate:self];
}

If I am logged in, I can successfully see the dialog to share the feed. But if I am not logged in, after this code block finishes, api dialog asks for my credentials. What I need is, if the user is not logged in, api shows the dialog, after the user successfully logs in, another dialog is shown to continue sharing progress.

Answer 1

You need to take a look at FBSessionDelegate. Here is my code for sharing

- (IBAction) facebookShare:(id)sender {
    AppDelegate *delegate = (AppDelegate *)[UIApplication sharedApplication].delegate;

    if (![delegate.facebook isSessionValid]) {
        [delegate.facebook authorize:[NSArray arrayWithObjects:@"publish_stream", @"offline_access", nil]];
    }
    else {
        NSMutableDictionary *params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
         [NSString stringWithFormat:@"TEXT", score.text], @"name",
         @"", @"caption",
         @"DESC.", @"description",
         @"link", @"link",
         @"imagelink", @"picture",
         nil];  
        [delegate.facebook dialog:@"feed"
               andParams:params
             andDelegate:self];
    }

}

#pragma mark - FB Session Delegate

- (void)fbDidLogin {
    AppDelegate *delegate = (AppDelegate *)[UIApplication sharedApplication].delegate;
    /*NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    [defaults setObject:[delegate.facebook accessToken] forKey:@"FBAccessTokenKey"];
    [defaults setObject:[delegate.facebook expirationDate] forKey:@"FBExpirationDateKey"];
    [defaults synchronize];*/
    NSMutableDictionary *params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
         [NSString stringWithFormat:@"TEXT", score.text], @"name",
         @"", @"caption",
         @"DESC.", @"description",
         @"link", @"link",
         @"imagelink", @"picture",
         nil];  
        [delegate.facebook dialog:@"feed"
               andParams:params
             andDelegate:self];
}

EDIT

For logout in cases of public cafe you need to make sure that u NEVER save access token in NSUSerDefaults as in FB Session delegate method fbDidLogin

Now implements FBDialogDelegate method

- (void)dialogDidComplete:(FBDialog *)dialog {
    AppDelegate *delegate = (AppDelegate *)[UIApplication sharedApplication].delegate;
    [delegate.facebook logout:self];
}