Facebook Connect Class with Singleton : Access token issue - objective-c

Question

I have created a singleton class called "LoginFacebook" which is meant to connect user to Facebook and to perform the different request. The problem is that I get an error about the access_token. Here it is :
3 : <CFString 0x4c552f0 [0xe50400]>{contents = "message"} = <CFString 0x4c55250 [0xe50400]>{contents = "An active access token must be used to query information about the current user."}
First I connect to Facebook by making the following request from another View Controller :
[[LoginFacebook loginFacebook] launchFacebook:self]
Then I make that second request from the same other View Controller but from another method :
[[LoginFacebook loginFacebook] requireName:self]
Here is my singleton class "LoginFacebook" :
LoginFacebook.h :
#import <UIKit/UIKit.h>
#import "LoginFacebook.h"
#interface FirstViewController : UIViewController {
}
-(IBAction)performConnect:(id)sender;
-(IBAction)performName:(id)sender;
#end
LoginFacebook.m :
#import "LoginFacebook.h"
static LoginFacebook *loginFacebook = nil;
#implementation LoginFacebook
#synthesize name;
#synthesize facebook;
-(void)launchFacebook:(id)sender
{
permissions = [[NSArray arrayWithObjects:
#"read_stream", #"publish_stream", #"offline_access",nil] retain];
Facebook* facebookbis = [[Facebook alloc] initWithAppId:#"168938499825684"];
facebook = facebookbis;
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
if ([defaults objectForKey:#"FBAccessTokenKey"]
&& [defaults objectForKey:#"FBExpirationDateKey"]) {
facebook.accessToken = [defaults objectForKey:#"FBAccessTokenKey"];
facebook.expirationDate = [defaults objectForKey:#"FBExpirationDateKey"];
}
if (![facebook isSessionValid]) {
[facebook authorize:nil delegate:self];
}
}
-(NSString *)requireName:(id)sender
{
NSLog(#"requireName asked");
[facebook requestWithGraphPath:#"me" andDelegate:self];
return name;
NSLog(#"%#",[facebook accessToken]);
}
+ (LoginFacebook *)loginFacebook
{
if (loginFacebook == nil) {
loginFacebook = [[super allocWithZone:NULL] init];
}
return loginFacebook;
}
+ (id)allocWithZone:(NSZone *)zone {
return [[self loginFacebook] retain];
}
- (id)copyWithZone:(NSZone *)zone {
return self;
}
- (id)retain {
return self;
}
- (NSUInteger)retainCount {
return NSUIntegerMax; //denotes an object that cannot be released
}
- (void)release {
//do nothing
}
- (id)autorelease {
return self;
}
// FBRequestDelegate
/**
* Called when the Facebook API request has returned a response. This callback
* gives you access to the raw response. It's called before
* (void)request:(FBRequest *)request didLoad:(id)result,
* which is passed the parsed response object.
*/
- (void)request:(FBRequest *)request didReceiveResponse:(NSURLResponse *)response {
NSLog(#"received response");
}
/**
* Called when a request returns and its response has been parsed into
* an object. The resulting object may be a dictionary, an array, a string,
* or a number, depending on the format of the API response. If you need access
* to the raw response, use:
*
* (void)request:(FBRequest *)request
* didReceiveResponse:(NSURLResponse *)response
*/
- (void)request:(FBRequest *)request didLoad:(id)result {
if ([result isKindOfClass:[NSArray class]]) {
result = [result objectAtIndex:0];
}
name = [result objectForKey:#"name"];
NSLog(#"request didLoad");
};
/**
* Called when an error prevents the Facebook API request from completing
* successfully.
*/
- (void)request:(FBRequest *)request didFailWithError:(NSError *)error {
name = [error localizedDescription];
NSLog(#"----request didFailWithError");
NSLog(#"%#", [error localizedDescription]);
NSLog(#"%#", [error description]);
};
////////////////////////////////////////////////////////////////////////////////
// FBDialogDelegate
/**
* Called when a UIServer Dialog successfully return.
*/
- (void)dialogDidComplete:(FBDialog *)dialog {
name = #"publish successfully";
}
#end
Please also note that I added the following method (with the corresponding FacebookLogin *facebook in the .h) to my App Delegate :
- (BOOL)application:(UIApplication *)application handleOpenURL:(NSURL *)url {
return [facebook handleOpenURL:url];
}
Does one of you know what is going wrong there ? I have been struggling with the code for 2 days now...

Answer 1

From the error message it seems your access token isn't valid anymore or you didn't even have an access token yet. Does your app actually open a web browser the first time a user is trying to access Facebook? If not, then you probably failed to configure the project properly.
Perhaps it'd be a good idea to share the code of my Facebook singleton - I believe the code is pretty clean and easy to understand & expand. Since my needs are currently very modest I only have a method to authorize (login) and another method to post to wall. I'm using a stack so I can perform some operations in the correct order (for example login before posting message to wall, if user isn't logged in yet).
SDFacebookController.h
#import <Foundation/Foundation.h>
#import "FBConnect.h"
#interface SDFacebookController : NSObject
<FBSessionDelegate,
FBRequestDelegate>
#property (nonatomic, retain) Facebook *facebook;
+ (SDFacebookController *)sharedController;
- (void)authorize;
- (void)postMessageToWall:(NSString *)message;
#end
SDFacebookController.m
#import "SDFacebookController.h"
#import "Constants+Macros.h"
#import "SDOperationStack.h"
#interface SDFacebookController ()
#property (nonatomic, retain) SDOperationStack *operationStack;
- (void)performAuthorization;
- (void)performPostMessageToWall:(NSString *)message;
- (void)runOperation;
#end
#implementation SDFacebookController
#synthesize facebook, operationStack;
#pragma mark - Instance methods
- (void)authorize
{
NSInvocationOperation *operation = [[[NSInvocationOperation alloc] initWithTarget:self selector:#selector(performAuthorization) object:nil] autorelease];
[operationStack push:operation];
[self runOperation];
}
- (void)postMessageToWall:(NSString *)message
{
NSInvocationOperation *operation = [[[NSInvocationOperation alloc] initWithTarget:self selector:#selector(performPostMessageToWall:) object:message] autorelease];
[operationStack push:operation];
if (![facebook isSessionValid])
{
NSInvocationOperation *operation = [[[NSInvocationOperation alloc] initWithTarget:self selector:#selector(performAuthorization) object:nil] autorelease];
[operationStack push:operation];
}
[self runOperation];
}
#pragma mark - Private methods
- (void)runOperation
{
NSOperation *operation = [operationStack pop];
[[NSOperationQueue currentQueue] addOperation:operation];
}
- (void)performAuthorization
{
if (![facebook isSessionValid])
{
NSArray *permissions = [NSArray arrayWithObject:#"publish_stream"];
[facebook authorize:permissions delegate:self];
}
}
- (void)performPostMessageToWall:(NSString *)message
{
NSMutableDictionary *params = [NSMutableDictionary dictionaryWithObjectsAndKeys:message, #"message", nil];
[facebook requestWithGraphPath:#"me/feed" andParams:params andHttpMethod:#"POST" andDelegate:self];
}
#pragma mark - FBRequestDelegate
/**
* Called just before the request is sent to the server.
*/
- (void)requestLoading:(FBRequest *)request
{
DLog(#"%#", request);
}
/**
* Called when the server responds and begins to send back data.
*/
- (void)request:(FBRequest *)request didReceiveResponse:(NSURLResponse *)response
{
DLog(#"%# %#", request, response);
}
/**
* Called when an error prevents the request from completing successfully.
*/
- (void)request:(FBRequest *)request didFailWithError:(NSError *)error
{
DLog(#"%# %#", request, error);
[[[[UIAlertView alloc] initWithTitle:NSLocalizedString(#"Error", nil)
message:[error localizedDescription]
delegate:nil
cancelButtonTitle:NSLocalizedString(#"OK", nil)
otherButtonTitles:nil]
autorelease] show];
[operationStack empty];
}
/**
* Called when a request returns and its response has been parsed into
* an object.
*
* The resulting object may be a dictionary, an array, a string, or a number,
* depending on thee format of the API response.
*/
- (void)request:(FBRequest *)request didLoad:(id)result
{
DLog(#"%# %#", request, result);
if ([operationStack isEmpty] == NO)
[self runOperation];
else if ([operationStack.lastOperation.invocation selector] == #selector(performPostMessageToWall:))
[[[[UIAlertView alloc] initWithTitle:NSLocalizedString(#"MessagePosted", nil)
message:NSLocalizedString(#"Successfully posted message on Facebook.", nil)
delegate:nil
cancelButtonTitle:NSLocalizedString(#"OK", nil)
otherButtonTitles:nil]
autorelease] show];
}
/**
* Called when a request returns a response.
*
* The result object is the raw response from the server of type NSData
*/
- (void)request:(FBRequest *)request didLoadRawResponse:(NSData *)data
{
DLog(#"%# %#", request, data);
}
#pragma mark - FBSessionDelegate
/**
* Called when the user successfully logged in.
*/
- (void)fbDidLogin
{
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:[facebook accessToken] forKey:#"FBAccessTokenKey"];
[defaults setObject:[facebook expirationDate] forKey:#"FBExpirationDateKey"];
[defaults synchronize];
}
/**
* Called when the user dismissed the dialog without logging in.
*/
- (void)fbDidNotLogin:(BOOL)cancelled
{
}
/**
* Called when the user logged out.
*/
- (void)fbDidLogout
{
}
#pragma mark - Memory management
- (id)init
{
self = [super init];
if (self)
{
facebook = [[Facebook alloc] initWithAppId:kFacebookAppIdentifier];
operationStack = [[SDOperationStack alloc] init];
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
if ([defaults objectForKey:#"FBAccessTokenKey"] && [defaults objectForKey:#"FBExpirationDateKey"])
{
facebook.accessToken = [defaults objectForKey:#"FBAccessTokenKey"];
facebook.expirationDate = [defaults objectForKey:#"FBExpirationDateKey"];
}
}
return self;
}
- (void)dealloc
{
[operationStack release];
[facebook release];
[super dealloc];
}
#pragma mark - Singleton
+ (SDFacebookController *)sharedController
{
static SDFacebookController *controller = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
controller = [[self alloc] init];
});
return controller;
}
#end
SDOperationStack.h
#import <Foundation/Foundation.h>
#interface SDOperationStack : NSObject
#property (nonatomic, retain) NSInvocationOperation *lastOperation;
- (void)push:(NSOperation *)operation;
- (NSOperation *)pop;
- (BOOL)isEmpty;
- (void)empty;
#end
SDOperationStack.m
#import "SDOperationStack.h"
#interface SDOperationStack ()
#property (nonatomic, retain) NSMutableArray *array;
#end
#implementation SDOperationStack
#synthesize array, lastOperation;
- (void)dealloc
{
[lastOperation release];
[array release];
[super dealloc];
}
- (id)init
{
self = [super init];
if (self)
{
array = [[NSMutableArray alloc] init];
}
return self;
}
- (void)push:(NSInvocationOperation *)operation
{
[array addObject:operation];
}
- (NSInvocationOperation *)pop
{
if ([self isEmpty])
return nil;
self.lastOperation = (NSInvocationOperation *)[array lastObject];
[array removeLastObject];
return lastOperation;
}
- (BOOL)isEmpty
{
return [array count] == 0;
}
- (void)empty
{
[array removeAllObjects];
}
#end