ACAccountCredential returns null for oauthToken - ios

Question

I am getting access to user's facebook via:
[accStore requestAccessToAccountsWithType:fbAccountType
options:options
completion:^(BOOL granted, NSError *error) {
if (granted) {
// If access granted, then get the Facebook account info
NSArray *accounts = [accStore
accountsWithAccountType:fbAccountType];
ACAccount *acc = [accounts lastObject];
// Get the access token, could be used in other scenarios
ACAccountCredential *fbCredential = [acc credential];
NSString *accessToken = [fbCredential oauthToken];
NSLog(#"Facebook Access Token: %#", accessToken);
// Add code here to make an API request using the SLRequest class
} else {
NSLog(#"Access not granted");
}
}];
This prints out:
Facebook Access Token: (null)
I am granted access, but the token is null. What am I doing wrong?
Thanks

Answer 1

I've solved the problem by renewing the credentials. That is, after access to FB has been granted, but in the case where ACAccountCredential's oauthToken returns nil, we just call ACAccountStore's renewCredentialsForAccount. Credentials are renewed, and after that the token is valid!

Answer 2

Here's some info from Apple doc:
#property(nonatomic, retain) ACAccountCredential *credential
Discussion This property is required and must be set before the
account is saved. For privacy reasons, this property is inaccessible
after the account is saved.
As in your code, [acc credential] will return null
For reference, http://developer.apple.com/library/ios/#documentation/Accounts/Reference/ACAccountClassRef/Reference/Reference.html#//apple_ref/doc/uid/TP40011019
Found a similar post here: Get Facebook access token from Social.framework(iOS6)
Hope this can help.