User not logged out from Dropbox and Google drive when deleting app - ios

Question

I am using Dropbox and Google Drive integration in my iOS app. I can fetch files from both drives and view listing in tableview. However, when I delete the app on my iPhone without logout from these drives, it still shows logged in when I install new app. How to logout user when I delete the app or remove session?
For Dropbox i am using ObjectiveDropboxOfficial apiV2 and for Google Drive i am using GoogleAPIClientForREST, GTMSessionFetcher etc libraries.
My code:
[DBClientsManager setupWithAppKey:#"my-key"];
[DBClientsManager authorizeFromController:[UIApplication sharedApplication]
controller:self openURL:^(NSURL *url) {
[[UIApplication sharedApplication] openURL:url];
}];
//AppDelegate
if ([DBClientsManager handleRedirectURL:url])
{
if (DBClientsManager.authorizedClient || DBClientsManager.authorizedTeamClient) {
// NSLog(#"App linked successfully!");
// At this point you can start making API calls
NSNotification *notification = [NSNotification notificationWithName:#"DropboxLoggedIn" object:nil];
[[NSNotificationCenter defaultCenter] postNotification:notification];
}
return YES;
}

Answer 1

If these services are designed this way I assume they save credentials in keychain which persists data and your application is already logged in when reinstalled or keychain is anyhow transfered.
If this is not your desired effect I can only assume you will need to log out from these services manually. This means you will need to track these logins and logouts and then when the app starts simply log out from all services which have not been tracked as logged in by you.
It is an ugly thing to do but it is a solution:
When a service is logged in save a value in user defaults
- (void)serviceDidLogin:(ServiceType)type {
[[NSUserDefaults standardUserDefaults] setBool:YES forKey:[self keyForServiceType: type]];
}
Then when it is logged out you need to clear it
- (void)serviceDidLogout:(ServiceType)type {
[[NSUserDefaults standardUserDefaults] removeObjectForKey:[self keyForServiceType: type]];
}
Then when app starts you need to log out from all of the services that you have no recording of being logged into:
- (void)logOutFromAllUnusedService {
for(int i=0; i<ServiceTypeCount; i++) {
ServiceType type = i;
if([[NSUserDefaults standardUserDefaults] boolForKey:[self keyForServiceType: type]] == NO) {
[self logoutFromService:type];
}
}
}
No matter how you do this but my situation assumes ServiceType is an enum like so:
typedef enum {
// Never assign values to enums
ServiceTypeDropbox,
ServiceTypeGoogleDrive,
ServiceTypeCount, // Always last of the valid
// Move deprecated services here
ServiceTypeDeprecated1 // TODO: remove at some point
} ServiceType;