Check if Facebook account is linked to PFUser - ios

Question

In the Parse docs, it says that you can check if a user is linked to a Facebook account, but is there any way to do it vice versa? For example, suppose the user clicks a button to sign in with Facebook, since [PFUser currentUser] is nil (because the user hasn't logged in yet), Parse will create a NEW account for that user since you can't use [PFFacebookUtils isLinkedWithUser: [PFUser currentUser]]. It seems like the only way to link an account is after the user has logged in regularly(i.e. entering their username and password), but that's really inconvenient. What if the user has already created an accounted manually (by filling out a the registration form I provide) and then decides to link their Facebook account? SO is there anyway to check if a Facebook account is linked with a user in general rather than checking it against a specific user?

Answer 1

Ok here is the solution. Basically iterate through every user and see if Facebook account is linked with that. based on that, link or create a new account. Here is code:
PFQuery *userQuery = [PFUser query];
[userQuery findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
NSUInteger count = [objects count];
BOOL linked = NO;
for(NSUInteger i = 0; i < count; i++){
PFUser *checkUser = objects[i];
if([PFFacebookUtils isLinkedWithUser:checkUser]){
linked = YES;
NSLog(#"profile is linked to a user");
break;
}
}
if(linked == YES){
[PFFacebookUtils logInWithPermissions:_permissions block:^(PFUser *user, NSError *error) {
if(!user){
NSLog(#"facebook cancelled");
}
else{
_type = #"twitter";
[self performSegueWithIdentifier:#"showMain" sender:self]; }
}
];
}
else{
CCAlertView *ask = [[CCAlertView alloc]initWithTitle:#"Are you already registered" message:nil];
[ask addButtonWithTitle:#"No" block:^{
[PFFacebookUtils logInWithPermissions:_permissions block:^(PFUser *user, NSError *error) {
if(!user){
NSLog(#"Facebook cancelled");
}
else if(user.isNew){
_type = #"facebook";
[self performSegueWithIdentifier:#"showMain" sender:self]; }
else{
[self performSegueWithIdentifier:#"showMain" sender:self]; }
}];
}];
[ask addButtonWithTitle:#"Yes" block:^{
CCAlertView *log = [[CCAlertView alloc]initWithTitle:#"Enter username and password" message:nil];
[log setAlertViewStyle:UIAlertViewStyleLoginAndPasswordInput];
UITextField *un = [log textFieldAtIndex:0];
UITextField *pw = [log textFieldAtIndex:1];
[log addButtonWithTitle:#"Cancel" block:nil];
[log addButtonWithTitle:#"Enter" block:^{
[PFUser logInWithUsernameInBackground:[un text] password:[pw text] block:^(PFUser *user, NSError *error) {
if(user){
[PFFacebookUtils linkUser:user permissions:_permissions block:^(BOOL succeeded, NSError *error) {
if(succeeded){
NSLog(#"linked");
[self performSegueWithIdentifier:#"showMain" sender:self]; }
else{
NSLog(#"couldnt link");
}
}];
}
else{
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:#"Oops!" message:[error userInfo] delegate:self cancelButtonTitle:nil otherButtonTitles:#"okay", nil];
[alert show];
}
}];
}];
[log show];
}];
[ask show];
}
}];