ios - AFRESTClient pathForEntity具有嵌套资源？

Question

我正在尝试使用嵌套的资源URL在相册中获取照片，例如:

GET http://www.myapi.com/albums/:album_id/photos

似乎最简单的方法是通过覆盖我的AFRESTClient子类中的pathForEntity函数。但是，我无权访问相册对象，因此无法返回包含album_id的URL。我应该如何覆盖/扩展来完成此任务？请参阅下文，了解我如何尝试执行此操作，请注意我无法提供相册ID的问号:

- (NSString *)pathForEntity:(NSEntityDescription *)entity {

  NSString *path = AFPluralizedString(entity.name);

  if ([entity.name isEqualToString:@"Photo"]) {
    path = [NSString stringWithFormat:@"albums/%d/photos", ??];
  }

  return path;
}

在堆栈的更高处，我在PhotosViewController -viewDidLoad中拥有它

- (void)viewDidLoad
{
  [super viewDidLoad];

  self.title = self.currentAlbum.name;

  NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] initWithEntityName:@"Photo"];
  fetchRequest.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"createdAt" ascending:NO]];

  NSPredicate *predicate = [NSPredicate predicateWithFormat:@"album == %@", self.currentAlbum];
  fetchRequest.predicate = predicate;

  self.fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:nil];
  self.fetchedResultsController.delegate = self;
  [self.fetchedResultsController performFetch:nil];
}

谢谢!

Answer 1

我们具有相似的层次结构，最终在我们的AFRESTClient子类中实现pathForRelationship:forObject:方法。以您的相册和照片为例，我想它会是这样的:

- (NSString *)pathForRelationship:(NSRelationshipDescription *)relationship
                        forObject:(NSManagedObject *)object
{
    if ([object isKindOfClass:[Album class]] && [relationship.name isEqualToString:@"photos"]) {
        Album *album = (Album*)object;
        return [NSString stringWithFormat:@"/albums/%@/photos", album.album_id];
    }
    return [super pathForRelationship:relationship forObject:object];
}

这是假设您在模型中设置了toMany关系。