Social API Facebook iOS: "Error validating access token: Session has expired on"

Question

In my iOS app I use with the Social Framework the Facebook API to make request to share with Facebook, but now I receive this status code from Facebook:

{
    error =     {
        code = 190;
        "error_subcode" = 463;
        message = "Error validating access token: Session has expired on 25 marzo 2014 16.20. The current time is 18 aprile 2014 8.45.";
        type = OAuthException;
    };
}

This is the code i use:

ACAccountType *facebookTypeAccount = [accountStore accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierFacebook];

NSDictionary *options = @{ACFacebookAppIdKey: @"##myfbid###",ACFacebookPermissionsKey: @[@"email"]};

[accountStore requestAccessToAccountsWithType:facebookTypeAccount
    options:options
    completion:^(BOOL granted, NSError *error) {
        if(granted){
            NSArray *accounts = [accountStore accountsWithAccountType:facebookTypeAccount];
            facebookAccount = [accounts lastObject];
            //NSLog(@"Success");

            NSURL *meurl = [NSURL URLWithString:@"https://graph.facebook.com/me"];
            SLRequest *merequest = [SLRequest requestForServiceType:SLServiceTypeFacebook
                requestMethod:SLRequestMethodGET
                URL:meurl
                parameters:nil];
            merequest.account = facebookAccount;
            [merequest performRequestWithHandler:^(NSData *responseData, NSHTTPURLResponse *urlResponse, NSError *error) {
                NSDictionary *json = [NSJSONSerialization JSONObjectWithData:responseData options:0 error:&error];
                //this json conaints the log i write above
        }

];

So i have tried to logout from the Facebook account in the iPhone Setting, and then login again, so my question is there is a way to automatically refresh this token every time the app open to avoid this problem?

Answer 1

You cannot "automatically", refresh the access token. Whenever you get the response, you should check for the error and if error exists renew the token. This code may help you-

....
if([json.profileDictionary objectForKey:@"error"]!=nil){
   [self renewCredentials]; 
}

-(void)renewCredentials{
    [self.accountStore renewCredentialsForAccount:(ACAccount *)self.facebookAccount completion:^(ACAccountCredentialRenewResult renewResult, NSError *error){
        if(!error){
            switch (renewResult) {
                case ACAccountCredentialRenewResultRenewed:
                    NSLog(@"Good to go");
                    [self getFacebookAccount];
                    break;
                case ACAccountCredentialRenewResultRejected:
                    NSLog(@"User declined permission");
                    break;
                case ACAccountCredentialRenewResultFailed:
                    NSLog(@"non-user-initiated cancel, you may attempt to retry");
                    break;
                default:
                    break;
            }
        }
        else{
            //handle error
            NSLog(@"error from renew credentials%@",error);
        }
    }];
}

Hope that helps!