Question

I am a .Net developer and very new to Xcode. I am using WCF for the server side process and send/receive JSON data between iphone app and WCF. I want the native iPhone app to do below:

1. Registration and Login view
2. Once user click login button, it sends username and password entered in JSON format to my WCF service to authenticate, if login is valid, WCF will return a valid member GUID and a token string
3. iPhone app receives the member guid and token, and stores them in a “persistent variable”, and I will load new views for authenticated users. So member has access to all functions/views.
4. Every time I post data between iphone app and WCF, I need to use that member guid and token from the variable so the WCF service knows which member is requesting data.
5. Every time user shutdown or restart iphone, I hope my app can remember the member guid, so they don’t have to login again.
6. User can click a logout button, and it will clear the variable and return to login view.

I am not sure if this is the correct way of iphone app login process?

I have already done WCF authentication and send back JSON, but now I need to store member GUID, Can someone please point me to the right direction? What should I use to store that information that can be used later on? An example would be great!

Answer 1

Sounds like the perfect sort of thing for the NSUserDefaults. Use them like this:

NSUserDefaults *myUserDefaults = [NSUserDefaults standardUserDefaults];
[myUserDefaults setObject: @"the key" forKey: @"key"];

You can also use other functions to set different kinds of data, like setInteger:forKey: or setValue:forKey:. To recall your data, use this function:

NSString *theKey = [myUserDefaults objectForKey:@"key"];

and the return value will be the object you stored in it. Other data types work similarly with functions like integerForKey: and valueForKey:.