How to get session login information to my UIWebView by FacebookSDK - iphone

Question

After logging in to facebook with FacebookSDK, and I want to display a page using a UIWebView.
It is displayed correctly when I login for the first time.
But I close and restart the app, Even though the facebook session still open, I can't get login session to my UIWebView.
Do you have any suggestions for that, when I re-run the app, to get as it is the Facebook session information?
This is my code example.
#interface FBLogin2ViewController ()
#end
#implementation FBLogin2ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
if (FBSession.activeSession.state == FBSessionStateCreatedTokenLoaded) {
// To-do, show logged in view
NSString *appID = [FBSession defaultAppID];
NSLog(#"Session token exists %#", appID);
}
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)onLogin:(id)sender {
NSArray *permissions = nil;
if (![FBSession activeSession]) {
FBSession *session = [[FBSession alloc] initWithAppID:#"000000000000" permissions:permissions defaultAudience:FBSessionDefaultAudienceEveryone urlSchemeSuffix:#"fb" tokenCacheStrategy:nil];
[FBSession setActiveSession:session];
}
else if( [FBSession activeSession].isOpen )
{
[[FBSession activeSession] closeAndClearTokenInformation];
FBSession.activeSession = nil;
}
[[FBSession activeSession] openWithBehavior:FBSessionLoginBehaviorForcingWebView
completionHandler:^(FBSession *session, FBSessionState state, NSError *error) {
[self sessionStateChanged:session state:state error:error];
}];
}
- (IBAction)onLogout:(id)sender {
[FBSession.activeSession closeAndClearTokenInformation];
FBSession.activeSession = nil;
}
- (IBAction)onGoWeb:(id)sender {
NSURL *url = [NSURL URLWithString:#"http://www.facebook.com/xxxxx?fref=xx"];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
[_webView loadRequest:request];
_webView.delegate = self;
}
- (void)sessionStateChanged:(FBSession *)session
state:(FBSessionState) state
error:(NSError *)error
{
switch (state) {
case FBSessionStateOpen: {
}
break;
case FBSessionStateClosed:
case FBSessionStateClosedLoginFailed:
// Once the user has logged in, we want them to
// be looking at the root view.
break;
default:
break;
}
if (error) {
UIAlertView *alertView = [[UIAlertView alloc]
initWithTitle:#"Error"
message:error.localizedDescription
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alertView show];
}
}
#end

Answer 1

1)call openFBSessionIfAvaliable in didFinishLaunchingWithOptions method
//in appdelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
[self openFBSessionIfAvaliable];
}
//in appdelegate
- (BOOL)application:(UIApplication *)application
openURL:(NSURL *)url
sourceApplication:(NSString *)sourceApplication
annotation:(id)annotation {
// attempt to extract a token from the url
return [[FBSession activeSession] handleOpenURL:url];
}
//in appdelegate
- (void)applicationDidBecomeActive:(UIApplication *)application
{
// Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
[[FBSession activeSession] handleDidBecomeActive];
}
//in appdelegate
- (void)applicationWillTerminate:(UIApplication *)application
{
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
[[FBSession activeSession] close];
}
-(void)openFBSessionIfAvaliable
{
[FBSession setActiveSession:[FBSession new]];
if ([FBSession activeSession].state == FBSessionStateCreatedTokenLoaded)
{
[self openFBSessionWithAllowLoginUI:NO];
}
}
- (BOOL)openFBSessionWithAllowLoginUI:(BOOL)allowLoginUI
{
NSArray *permissions = [[NSArray alloc] initWithObjects:
#"email",nil];
return [FBSession openActiveSessionWithReadPermissions:permissions
allowLoginUI:allowLoginUI
completionHandler:^(FBSession *session,
FBSessionState state,
NSError *error)
{
[self sessionStateChanged:session
state:state
error:error];
}];
}
- (void)sessionStateChanged:(FBSession *)session
state:(FBSessionState) state
error:(NSError *)error
{
switch (state)
{
case FBSessionStateOpen:
if (!error)
{
NSString *_facebookToken = [[FBSession activeSession] accessToken];
NSString *_facebookEmail = [user objectForKey:#"email"];
}
break;
case FBSessionStateClosed:
case FBSessionStateClosedLoginFailed:
[FBSession.activeSession closeAndClearTokenInformation];
break;
default:
break;
}
if (error)
{
[FBSession.activeSession closeAndClearTokenInformation];
/*UIAlertView *alertView = [[UIAlertView alloc]
initWithTitle:#"Error"
message:#"Please try Again"
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alertView show];*/
}
}
2) On button Click of "Login via facebook" call below method
[self openFBSessionWithAllowLoginUI:YES];
3) Now every time when you launch the app, it will check the Facebook session, if found then proceed further otherwise show the button "Login via Facebook".session
I hope it will solve your problem.