iPhone Facebook app: Where does the "permissions array" code go? - iphone

Question

I just went through the "Getting Started > Mobile Apps" documentation on Facebook developers. They provided the code to ask permission for accessing information but they don't specify where that code is suppose to go.
Could you tell me where to put the code? Because I don't want to put it in the wrong space.
The code I want to add:
NSArray* permissions = [[NSArray arrayWithObjects:
#"publish_stream", #"offline_access", nil] retain];
[facebook authorize:permissions delegate:self];
My appDelegate code:
#import "iOSTestAppDelegate.h"
#implementation iOSTestAppDelegate
#synthesize facebook;
#synthesize viewController=_ViewController;
#synthesize window=_window;
#synthesize managedObjectContext=__managedObjectContext;
#synthesize managedObjectModel=__managedObjectModel;
#synthesize persistentStoreCoordinator=__persistentStoreCoordinator;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// Override point for customization after application launch.
[self.window makeKeyAndVisible];
/* Step 2. Within the body of the application:didFinishLaunchingWithOptions: method create instance of the Facebook class using your app id */
facebook = [[Facebook alloc] initWithAppId:#"********"];
/* Step 3. Once the instance is created, check for previously saved access token information. */
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
if ([defaults objectForKey:#"FBAccessTokenKey"]
&& [defaults objectForKey:#"FBExpirationDateKey"]) {
facebook.accessToken = [defaults objectForKey:#"FBAccessTokenKey"];
facebook.expirationDate = [defaults objectForKey:#"FBExpirationDateKey"];
}
/* Step 4. Check for a valid session and if it is not valid call the authorize method which will both signin the user and prompt the user to authorize the app: */
if (![facebook isSessionValid]) {
[facebook authorize:nil delegate:self];
}
return YES;
}
/* Step 5. Add the application:handleOpenURL: method to the AppDelegate with a call to the facebook instance: */
- (BOOL)application:(UIApplication *)application handleOpenURL:(NSURL *)url {
return [facebook handleOpenURL:url];
}
/* Step 6. Implement the fbDidLogin method from the FBSessionDelegate implementation. In this method you will save the user's credentials specifically the access token and corresponding expiration date. */
- (void)fbDidLogin {
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:[facebook accessToken] forKey:#"FBAccessTokenKey"];
[defaults setObject:[facebook expirationDate] forKey:#"FBExpirationDateKey"];
[defaults synchronize];
}
...
#end

Answer 1

After allocate your facebook instance, you have to provide these permission for authorizing the facebook from the user_credentials. it means were getting these permission from the user who are login.
facebook=[[Facebook alloc]initWithAppId:kAppId];
_permissions = [[NSArray arrayWithObjects:#"publish_stream",#"offline_access",nil]retain];
[facebook authorize:_permissions delegate:self];
Publish stream provides : Enables your app to post content, comments, and likes to a user's stream and to the streams of the user's friends. With this permission, you can publish content to a user's feed at any time, without requiring offline_access. However, please note that Facebook recommends a user-initiated sharing model.
Offline Access:
Enables your app to perform authorized requests on behalf of the user at any time. By default, most access tokens expire after a short time period to ensure applications only make requests on behalf of the user when the are actively using the application. This permission makes the access token returned by our OAuth endpoint long-lived.
Refer more details about permission here