Facebook IOS SDK trying to make singleton class? - iphone

Question

Hy, i am trying to make from Facebook IOS SDK (Octomber 2011) a class of my own in where i can make all the methods and functions that i need and just import this class in any of my application view controllers and call it.
So this way i don't need to do all the initialization and delegation to the controllers in where i use the facebook.
So i want to do like this, [myfacebookclass initwithappID:myappid]
[myfacebookclass postmessage:#"some message"];
The thing is when i am seting authorizeWithFBAppAuth:YES safariAuth:YES flags in facebook.m ( the original class) and i do a postmessage it redirects me on Facebook Application or Safari and check's for permision, i hit ok and then redirects me in my application and doesn't post message.
WHen i am trying to post message i do like this :
This is in my own facebook class
myfacebookclass *facebook2;
+(void)initWithAppID:(NSString*) facebookAppId {
if (facebook2 == nil) {
facebook2 = [myfacebookclass new];
[facebook2 setWithAppId:facebookAppId];
}
}
- (void) postMessage1:(NSString *)messageToPost {
if ([self.facebook isSessionValid]) {
NSMutableDictionary *params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
self.applicationID, #"api_key",
messageToPost, #"message",
nil];
[self.facebook requestWithGraphPath:#"me/feed" andParams:params andHttpMethod:#"POST" andDelegate:self];
} else {
NSArray * neededPermissions = [[[NSArray alloc] initWithObjects:#"user_about_me", #"publish_stream", nil] autorelease];
[self.facebook authorize:neededPermissions];
}
}
+ (void)postMessage:(NSString*) message {
[facebook2 postMessage1:message];
}
I also implemented:
(BOOL)application:(UIApplication *)application openURL:(NSURL *)url
sourceApplication:(NSString *)sourceApplication annotation:(id)annotation
{
return [facebook handleOpenURL:url];
}
i've didn't modified facebook.m or other classes in Facebook IOS SDK.

Answer 1

a good practice when making a singleton class is to use shared instance. Correct singleton also has to include some memory management overridden methods. In your case it can be done like this:
#implementation FacebookManager
static FacebookManager *mySharedFacebookManager;
+ (FacebookManager*)sharedFacebookManager {
#synchronized(self) {
if(mySharedFacebookManager == nil) {
mySharedFacebookManager = [[self alloc] init];
}
}
return mySharedFacebookManager;
}
+ (id)allocWithZone:(NSZone *)zone {
#synchronized(self) {
if(mySharedFacebookManager == nil) {
mySharedFacebookManager = [super allocWithZone:zone];
return mySharedFacebookManager;
}
}
return nil;
}
- (id)copyWithZone:(NSZone *)zone {
return self;
}
- (id)retain {
return self;
}
- (unsigned)retainCount {
return UINT_MAX;
}
- (oneway void)release {
}
- (id)autorelease {
return self;
}
In your case you may have Facebook type object as ivar, and some methods to wrap over FB API, for example like this:
- (id)init {
self = [super init];
if(self) {
facebook = [[Facebook alloc] initWithAppId:FB_APP_ID andDelegate:self];
// restore previous session
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
if ([defaults objectForKey:#"FBAccessTokenKey"]
&& [defaults objectForKey:#"FBExpirationDateKey"]) {
facebook.accessToken = [defaults objectForKey:#"FBAccessTokenKey"];
facebook.expirationDate = [defaults objectForKey:#"FBExpirationDateKey"];
}
...
}
return self;
}
- (void)login {
NSArray *permissions = [NSArray arrayWithObjects: #"user_about_me", #"publish_stream", nil];
[facebook authorize:permissions];
}
- (void)postToFeed:(NSString*)messageToPost {
NSMutableDictionary *params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
messageToPost, #"message",
nil];
[facebook requestWithGraphPath:#"me/feed"
andParams:params
andHttpMethod:#"POST"
andDelegate:self];
}
From other classes which have to deal with Facebook the construction is simple:
[[FacebookManager sharedFacebookManager] login];
...
[[FacebookManager sharedFacebookManager] postToFeed:#"Hello World!"];
I hope this snippets will help you.
To manage your facebook session you have to remember accessToken manually in FBSessionDelegate methods like that:
- (void)fbDidLogin {
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:[facebook accessToken] forKey:#"FBAccessTokenKey"];
[defaults setObject:[facebook expirationDate] forKey:#"FBExpirationDateKey"];
[defaults synchronize];
}
- (void)fbDidLogout {
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults removeObjectForKey:#"FBAccessTokenKey"];
[defaults removeObjectForKey:#"FBExpirationDateKey"];
[defaults synchronize];
}