iOS - Login view in UITabBarControler best practice - ios

Question

I've tabbar controller with 6 to 7 tabs on it with customization allowed (means that the user can change the order of tab bar display). And tab 1,3,5,7 requires the user to login access before seeing any contents on the view.
I don’t know as to how to identify which tabbar requires login access (Can we create #protocal or something). And after the user logs in successfully. I don’t know how to select the last tabbar, which the user has touched on.
I was using appdelegate by confiming to UITabBarControllerDelegate in AppDelegate
-(BOOL)tabBarController:(UITabBarController *)aTabBar shouldSelectViewController:(UIViewController *)viewController {
NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
BOOL hasValidLogin = [standardUserDefaults boolForKey:#"hasValidLogin"];
if (hasValidLogin == NO && /* I don't know to find a controller which requires login access*/) {
[LoginView showModal:viewController delegate:self];
return NO;
}
return YES;
}
pragma mark -
pragma mark LoginDelegate methods-
-(void)loginViewController:(LoginView *)loginViewController didLoginSuccess:NSString *)userName {
NSLog((#"%s [Line %d] "), __func__, __LINE__);
NSLog(#"userName = %#", userName);
NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
[standardUserDefaults setBool:YES forKey:#"hasValidLogin"];
[standardUserDefaults synchronize];
[self.tabBarController setSelected:/* How do i find the last touched tabbar*/];
}
Any good practice,recipes and code snippet you can direct me is appreciated.
I was reading matt's iOS Recipes. But I couldn't find anything related to this one.

Answer 1

Focus on UITabBarDelegate didSelectItem. Keep track of the previously selected tab item. If the user is not authenticated, pop up your authentication screen and select the previously selected tab item. Here is an example.
- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item {
switch ( item.tag ) {
case ME_TAB_BAR_TAG:
if ( [AppHelper checkAuthentication] ) {
[self showMe:YES];
} else if ( previousItem ) {
[tabBar setSelectedItem:previousItem];
return;
}
break;
case ITEMS_TAB_BAR_TAG:
[self showMe:NO];
break;
case CREATE_TAB_BAR_TAG:
if ( [AppHelper checkAuthentication] ) {
[self createNewItem];
} else if ( previousItem ) {
[tabBar setSelectedItem:previousItem];
return;
}
break;
}
previousItem = item;
}