objective-c - RestKit .2 将图像发布到 Web 服务 - 空实体错误

Question

我正在使用 RestKit 将图像发布到 Web 服务，它们发布得很好，服务器发回了 200。发生的情况是我收到以下错误:

*** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ valueForUndefinedKey:]: the entity (null) is not key value coding-compliant for the key "resource_updated_at".'

这是我用来发布图像的方法..我希望我遗漏了一些明显的东西。我发现了一篇类似的文章，其中提到核心数据堆栈可能未正确设置，但我不确定如何设置。我正在使用 RestKit 发布其他标准表单数据，它返回并映射得很好。

- (void)postImagesFromInventory:(NSManagedObject *)inventory {
    NSLog(@"######## postImagesFromInventory ########");

    // if there are photos that aren't synced, post the first one
    int postingImageNumber = 0;

    RKObjectManager *manager = [RKObjectManager managerWithBaseURL:[NSURL URLWithString:BASE_URL]];

    // send for each image in inventory
    for (Image *image in [[inventory valueForKey:@"image"] allObjects]) {
        postingImageNumber = postingImageNumber + 1;
        [SVProgressHUD setStatus:[NSString stringWithFormat:@"Posting image %d of %d for inventory %@", postingImageNumber, [[inventory valueForKey:@"image"] allObjects].count, [inventory valueForKey:@"asset_name"]]];

        // make sure it's not already synced
        if (![image valueForKey:@"synced"]) {
            NSLog(@"-------------------------------------");
            NSLog(@"need to post image for inventory %@",[inventory valueForKey:@"inventory_id"]);

            NSURL *imagePath = [NSURL URLWithString:[image valueForKey:@"path"]];

            // need to get my image from Asset Library
            ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
            __block NSNumber *imageSize = nil;
            __block UIImage *myImage = nil;
            __block Image *blockImage = nil;
            __block NSData *blockImageData = nil;

            [library assetForURL:imagePath resultBlock:^(ALAsset *asset) {
                myImage = [UIImage imageWithCGImage:[[asset defaultRepresentation] fullResolutionImage]];
                imageSize = [NSNumber numberWithLongLong:asset.defaultRepresentation.size];

                // make the image available on callback
                blockImage = image;

                NSData *imageData = UIImageJPEGRepresentation(myImage, 1.0);
                blockImageData = imageData;

                NSMutableURLRequest *request = [manager multipartFormRequestWithObject:inventory method:RKRequestMethodPOST path:IMAGES_ENDPOINT parameters:@{@"auth_token":@"my_auth_token",@"image" : @{@"asset_inventory_id":[inventory valueForKey:@"inventory_id"],@"resource_content_type":@"image/jpeg",@"resource_file_name":[NSString stringWithFormat:@"%@_image.jpg",[inventory valueForKey:@"asset_name"]],@"resource_file_size": [NSString stringWithFormat:@"%@",imageSize]}} constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
               [formData appendPartWithFileData:imageData
                                           name:@"image[resource]"
                                       fileName:[NSString stringWithFormat:@"%@_image.jpg",[inventory valueForKey:@"asset_name"]]
                                       mimeType:@"image/jpeg"];
            }];

            RKEntityMapping *mapping = [RKEntityMapping mappingForEntityForName:@"Image" inManagedObjectStore:_managedStore];
            [mapping addAttributeMappingsFromDictionary:@{@"resource_updated_at":@"resource_updated_at"}];
            [mapping mappingForDestinationKeyPath:@"image"];


            RKResponseDescriptor *responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:mapping pathPattern:nil keyPath:nil statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];

            [manager addResponseDescriptor:responseDescriptor];

            RKObjectRequestOperation *operation = [manager objectRequestOperationWithRequest:request success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
                NSLog(@"operation successful");
            } failure:^(RKObjectRequestOperation *operation, NSError *error) {
                NSLog(@"operation failed");
            }];

            // queue up the operation
            [manager enqueueObjectRequestOperation:operation];

            // library access failure
            } failureBlock:^(NSError *error) {
                NSLog(@"error : %@", error);
            }];
        }
    }
}

另外，这里是我设置 RKManagedObjectStore 的 init 方法，以防相关。

- (PSNDataSync *)init {
    RKLogConfigureByName("RestKit/Network*", RKLogLevelDebug);
    RKLogConfigureByName("RestKit/ObjectMapping", RKLogLevelDebug);

    PSNAppDelegate *appDelegate = (PSNAppDelegate *)[[UIApplication sharedApplication] delegate];
    _context = [appDelegate managedObjectContext];
    _managedStore = [[RKManagedObjectStore alloc] initWithManagedObjectModel:[appDelegate managedObjectModel]];

    _currentInventory = nil;
    _imagesArray = nil;

    // initialize imagesArray for loading inventoryCollectionView
    _imagesArray = [[NSMutableArray alloc]init];

    return self;
}

这是代表核心数据实体的图像类

#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>

@class Inventory;

@interface Image : NSManagedObject

@property (nonatomic, retain) NSString * path;
@property (nonatomic, retain) NSString * resource_updated_at;
@property (nonatomic, retain) NSNumber * synced;
@property (nonatomic, retain) Inventory *inventory;

@end

我将提出免责声明，这可能不是最好的代码..但如果您看到错误，请告诉我:]。

Answer 1

我遇到了完全相同的错误。您需要使用 RKObjectRequestOperation 的托管版本(RKManagedObjectRequestOperation)。