Question

In my iPhone app, I am using AFNetworking to make HTTP requests to a PHP API.

Every time I open the app, I have to login and the server will initiate the sessions.
After I log in, every time I will make an HTTP request to the API, the API knows that I have the session and will allow me to use every function of the API.

The problem is that after I close the app, I think that the sessions are destroyed and I am can’t use any functionality from the API without having to login again.

I am talking about an iPhone app here which uses AFNetworking to make the HTTP request.
From my tests I know that the session is destroyed after the app is closed.

I want to know if this is true and I want to know what’s the best way of making an authentication system. I think that session is not a solution anymore, since they are destroyed after the app is closed. My alternative was to create an auth_token every time someone logs in and store the token in the app, then every time someone open the app the first http request they will make it will contain the auth_token and if that token matches with the one from the database, then initialize the session as usual. I think that this can be a bit slower, providing that every time you open the app it will have to make an HTTPS request to initialize the connection between the client and the server.

So the question is: Is it true that you can keep the session alive after you close the app? Is it my alternative a good one?

Answer 1

This is the solution to my question.
If you are using AFNetworking the cookies are removed after you close the app. So to fix this you can save the cookies in user defaults and then load them when the app is open.

Save the cookies (you should check the name of the cookie first, mine was PHPSESSID, because you don’t want to save unuseful cookies):

    NSArray * all = [NSHTTPCookie cookiesWithResponseHeaderFields:[self.response allHeaderFields] forURL:[NSURL URLWithString:@"http://link.to.api" ]];
    for (NSHTTPCookie *cookie in all)
    {
        if([cookie.name compare:@"PHPSESSID"] == NSOrderedSame)
        {
            NSData *data = [NSKeyedArchiver archivedDataWithRootObject:cookie];
            [[NSUserDefaults standardUserDefaults] setObject:data forKey:@"MySavedCookies"];
            [[NSUserDefaults standardUserDefaults] synchronize];
        }
    }

Then when you load the app in “application didFinishLaunchingWithOptions” for example:

  NSData *cookiesdata = [[NSUserDefaults standardUserDefaults] objectForKey:@"MySavedCookies"];
  if([cookiesdata length])
  {
     NSHTTPCookie *cookie = [NSKeyedUnarchiver unarchiveObjectWithData:cookiesdata];
    [[NSHTTPCookieStorage sharedHTTPCookieStorage] setCookie:cookie];
  }