ios facebook user info - ios

Question

Can you help me how can I get user info.
NSString *name;
[FBRequestConnection startForMeWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error)
{
if (!error)
{
// Success! Include your code to handle the results here
name = [result objectForKey:#"first_name"]; // Error!!! how to get data from this handler
}
else
{
// An error occurred, we need to handle the error
// See: https://developers.facebook.com/docs/ios/errors
}
}];
Code described above - asynchronous? How to make it synchronous? Tell me about the mechanism or tell me where to read. Thank you!

Answer 1

You could read everything about Facebook SDK on this site: https://developers.facebook.com.
They don't provide synchronous API and I don't even know why you might need it. But if you really do you can do some workaround. See implementation:
__block id result = nil;
dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
[FBRequestConnection startForMeWithCompletionHandler:^(FBRequestConnection *connection, id theResult, NSError *error) {
result = theResult;
dispatch_semaphore_signal(semaphore); // UPDATE: dispatch_semaphore_wait call was here, which is wrong
}];
dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
NSLog(#"%#", result);// this code will be launched after you've received response from Facebook
Result conforms FBGraphUser protocol. So if you it doesn't contain value for first_name key, user wouldn't have specified it. You could print result in debugger and see what it is.

Answer 2

Seems like you totally mess up. Try this code, but be sure, your understand it:
- (void) SetUserData
{
[FBRequestConnection startForMeWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error)
{
if (!error)
{
self.first_name = [result objectForKey:#"first_name"];
NSLog(#"First name just came from server: first_name: %#", self.first_name);
}
else
{
}
}];
[self furtherProcessMethod];
}
- (void) furtherProcessMethod
{
if (self.first_name == nil)
{
// this is not recursion, do not miss that!!
[self performSelector:#selector(furtherProcessMethod) withObject:nil afterDelay:2.0];
}
else
{
NSLog(#"First name that I can work with first_name: %#", self.first_name);
// here you can handle you first_name, after it came
}
}
So after some time you need to get in log:
First name just came from server: first_name: some name
First name that I can work with first_name: some name

Answer 3

You can use additional method to solve your problem:
1) make name as property: __block NSString *name
2) move you code, that you need to perform, to separate method, like that:
- (void) methodWithComplitionHandler
{
name = nil;
[FBRequestConnection startForMeWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error)
{
if (!error)
{
name = [result objectForKey:#"first_name"];
}
else
{
}
}];
[self futherProcessMethod];
}
- (void) furtherProcessMethod
{
if (self.name == nil)
{
[self performSelector:#selector(furtherProcessMethod) withObject:nil afterDelay:3.0]; // here set appropriate delay
}
else
{
// do some with name;
}
}

Answer 4

As I clarify in previous answer, you need to work with name inside "else" statement. Please, debug for more understanding. So we have:
- (void) SetUserData
{
[FBRequestConnection startForMeWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error)
{
if (!error)
{
self.first_name = [result objectForKey:#"first_name"];
}
else
{
}
}];
[self furtherProcessMethod];
}
- (void) furtherProcessMethod
{
if (self.first_name == nil)
{
[self performSelector:#selector(furtherProcessMethod) withObject:nil afterDelay:30.0]; // here set appropriate delay
}
else
{
NSLog(#"first_name: %#", self.first_name);
}
}