Method to return block result - objective-c-blocks

Question

- (ACAccount *)accountFacebook{
if (_accountFacebook) {
return _accountFacebook;
}
if (!_accountStoreFacebook) {
_accountStoreFacebook = ACAccountStore.new;
}
ACAccountType *accountTypeFacebook = [self.accountStoreFacebook accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierFacebook];
NSDictionary *options = #{ACFacebookAppIdKey : #"xxxxxxxxx",
ACFacebookAudienceKey : ACFacebookAudienceEveryone,
ACFacebookPermissionsKey : #[#"user_about_me", #"publish_actions"]
};
__block ACAccount *accountFb;
[_accountStoreFacebook requestAccessToAccountsWithType:accountTypeFacebook options:options completion:^(BOOL granted, NSError *error) {
if (granted) {
NSLog(#"Facebook access granted");
accountFb = _accountStoreFacebook.accounts.lastObject;
}else {
NSLog(#"Facebook access denied");
accountFb = nil;}
if (error) {
NSLog(error.localizedDescription);
}
}];
return accountFb;
}
When I run
AppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
if (appDelegate.accountFacebook) {
NSLog(#"accountFacebook OK");
}else NSLog(#"accountFacebook Not Exists");
appDelegate.accountFacebook return nil always, doesn't wait for block to complete.
What should be changed?

Answer 1

This is an asynchronous call, so the block completes after your method ends. You need to redesign your app to do what it has to do in the completion block. You call appDelegate.accountFacebook and expect to do something if it is not nil. Why not pass this method a completion block that would perform what you want it to perform like so:
typedef void(^HandlerType)(ACAccount* account);
- (void)performForFacebookAccount: (HandlerType) handler{
if (_accountFacebook) {
handler(_accountFacebook);
return;
}
if (!_accountStoreFacebook) {
_accountStoreFacebook = ACAccountStore.new;
}
ACAccountType *accountTypeFacebook = [self.accountStoreFacebook accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierFacebook];
NSDictionary *options = #{ACFacebookAppIdKey : #"xxxxxxxxx",
ACFacebookAudienceKey : ACFacebookAudienceEveryone,
ACFacebookPermissionsKey : #[#"user_about_me", #"publish_actions"]
};
[_accountStoreFacebook requestAccessToAccountsWithType:accountTypeFacebook options:options completion:^(BOOL granted, NSError *error) {
if (granted) {
NSLog(#"Facebook access granted");
_accountFacebook = _accountStoreFacebook.accounts.lastObject;
handler(_accountFacebook);
}else {
NSLog(#"Facebook access denied");
_accountFacebook = nil;}
if (error) {
NSLog(error.localizedDescription);
}
}];
}