canLoadEntity.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{  
    // ...

    [Socialize setCanLoadEntityBlock:^BOOL(id<SocializeEntity> entity) { 
        return ![entity.name isEqualToString:@"DeletedEntity"];
    }];


}

entityLoader.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{  
    // ...

    [Socialize setEntityLoaderBlock:^(UINavigationController *navigationController, id<SocializeEntity>entity) {
        SampleEntityLoader *entityLoader = [[[SampleEntityLoader alloc] initWithEntity:entity] autorelease];
        [navigationController pushViewController:entityLoader animated:YES];
    }];
}