我在使用 RestKit 0.20pre6 发布 NSManagedObject 时遇到问题，它导致在我的 Rails 站点上创建一个值为 nil 的条目。我怀疑映射器，但据我所知，我已经正确设置了 RK 对象。例子很少，支持有限。该示例涉及 NSObjects 而不是 CoreData，因此我不得不做出一些假设。

这是我发布的代码，后面是控制台输出。该应用程序可以正常从服务器获取对象。

        // Sync the added object to the server
    // ****************************************

    RKObjecMapping *responseMapping = [RKObjectMapping mappingForClass:[Event class]];
//  RKEntityMapping *responseMapping = [RKEntityMapping mappingForEntityForName:@"Event" inManagedObjectStore:self.managedObjectStore];
    [responseMapping addAttributeMappingsFromDictionary:@{
     @"id": @"eventId",
     @"name": @"name",
     @"amount": @"amount",
     @"length": @"length",
     @"updated_at": @"updatedAt",
     @"created_at": @"createdAt",
     @"latitude": @"latitude",
     @"longitude": @"longitude",
     @"thumbnail": @"thumbnail",
     @"airTemp": @"airTemp",
     }];

    NSIndexSet *statusCodes = RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful); // Anything in 2xx
    RKResponseDescriptor *eventDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:responseMapping
                                                                                    pathPattern:@"/events"
                                                                                        keyPath:@"events"
                                                                                    statusCodes:statusCodes
                                                                                                ];

    RKObjectMapping *requestMapping = [RKObjectMapping requestMapping]; // objectClass == NSMutableDictionary

    [requestMapping addAttributeMappingsFromDictionary:@{
     @"id": @"eventId",
     @"name": @"name",
     @"amount": @"amount",
     @"length": @"length",
     @"updated_at": @"updatedAt",
     @"created_at": @"createdAt",
     @"latitude": @"latitude",
     @"longitude": @"longitude",
     @"thumbnail": @"thumbnail",
     @"airTemp": @"airTemp",
     }];


    // For any object of class Article, serialize into an NSMutableDictionary using the given mapping and nest
    // under the 'article' key path
    RKRequestDescriptor *requestDescriptor = [RKRequestDescriptor requestDescriptorWithMapping:requestMapping
                                                                                   objectClass:[Event class]
                                                                                   rootKeyPath:@"events"
                                                                                                ];

    LocationsAppDelegate *appDelegate = (LocationsAppDelegate *)[[UIApplication sharedApplication] delegate];
//  RKObjectManager *manager = [RKObjectManager managerWithBaseURL:gBaseURL];


    [RKObjectManager sharedManager].requestSerializationMIMEType = RKMIMETypeJSON;
    [[RKObjectManager sharedManager] addRequestDescriptor:requestDescriptor];
    [[RKObjectManager sharedManager] addResponseDescriptor:eventDescriptor];

    NSLog(@"RVC-addEvent %@ - %@", appDelegate.user.login, appDelegate.user.password);
    [[NBEventManager sharedManager] setUsername:appDelegate.user.login andPassword:appDelegate.user.password];
    appDelegate.objectManager.HTTPClient = [NBEventManager sharedManager];


    event = [eventsArray objectAtIndex:0];
    [[RKObjectManager sharedManager] postObject:event
                                           path:@"/events"
                                     parameters:nil
                                        success:nil
                                        failure:nil
                                                ];

}

2013-01-15 23:25:52.857 fish[38803:13403] I restkit.network:RKHTTPRequestOperation.m:152 POST 'http://localhost:3000/events' 2013-01-15 23:25:52.969 fish[38803:16903] I restkit.network:RKHTTPRequestOperation.m:179 POST 'http://localhost:3000/events' (201 Created) [0.1121 s] 2013-01-15 23:25:52.971 fish[38803:17507] D restkit.object_mapping:RKMapperOperation.m:360 Executing mapping operation for representation: { event = { airTemp = ""; amount = ""; "created_at" = "2013-01-16T04:25:52Z"; id = 54; latitude = ""; length = ""; longitude = ""; name = ""; thumbnail = ""; "updated_at" = "2013-01-16T04:25:52Z"; "user_id" = ""; }; } and targetObject: (entity: Event; id: 0x9c7f710 ; data: { airTemp = 0; amount = nil; createdAt = "2013-01-16 04:25:52 +0000"; eventId = 0; latitude = "28.158466"; length = 0; longitude = "-82.509215"; name = nil; photo = nil; thumbnail = nil; updatedAt = nil; }) 2013-01-15 23:25:52.971 fish[38803:17507] D restkit.object_mapping:RKMapperOperation.m:287 Found mappable data at keyPath 'event': { airTemp = ""; amount = ""; "created_at" = "2013-01-16T04:25:52Z"; id = 54; latitude = ""; length = ""; longitude = ""; name = ""; thumbnail = ""; "updated_at" = "2013-01-16T04:25:52Z"; "user_id" = ""; } 2013-01-15 23:25:52.971 fish[38803:17507] D restkit.object_mapping:RKMapperOperation.m:232 Asked to map source object { airTemp = ""; amount = ""; "created_at" = "2013-01-16T04:25:52Z"; id = 54; latitude = ""; length = ""; longitude = ""; name = ""; thumbnail = ""; "updated_at" = "2013-01-16T04:25:52Z"; "user_id" = ""; } with mapping eventId>", " name>", " amount>", " length>", " updatedAt>", " createdAt>", " latitude>", " longitude>", " airTemp>", " thumbnail>" )> 2013-01-15 23:25:52.971 fish[38803:17507] D restkit.object_mapping:RKMappingOperation.m:754 Starting mapping operation... 2013-01-15 23:25:52.972 fish[38803:17507] D restkit.object_mapping:RKMappingOperation.m:818 Finished mapping operation successfully... 2013-01-15 23:25:52.973 fish[38803:17507] D restkit.object_mapping:RKMapperOperation.m:316 Found unmappable value at keyPath: events 2013-01-15 23:25:52.973 fish[38803:17507] D restkit.object_mapping:RKMapperOperation.m:389 Finished performing object mapping. Results: { event = " (entity: Event; id: 0x9c7f710 ; data: {\n airTemp = nil;\n amount = nil;\n createdAt = \"2013-01-16 04:25:52 +0000\";\n eventId = 54;\n latitude = nil;\n length = nil;\n longitude = nil;\n name = nil;\n photo = nil;\n thumbnail = nil;\n updatedAt = \"2013-01-16 04:25:52 +0000\";\n})"; } 2013-01-15 23:25:52.973 fish[38803:13403] D restkit.core_data:RKManagedObjectRequestOperation.m:534 Skipping deletion of orphaned objects: only performed for GET requests. 2013-01-15 23:25:52.976 fish[38803:11f03] D restkit.core_data:RKManagedObjectRequestOperation.m:599 Refreshing mapped target object (entity: Event; id: 0x9c7f710 ; data: { airTemp = nil; amount = nil; createdAt = "2013-01-16 04:25:52 +0000"; eventId = 54; latitude = nil; length = nil; longitude = nil; name = nil; photo = nil; thumbnail = nil; updatedAt = "2013-01-16 04:25:52 +0000"; }) in context

现在这是我的代码，因为我已将所有映射移至应用程序委托(delegate)并已实现 RKEntityMapping。我仍然没有 JSON 对象附加到 POST 调用。

    RKEntityMapping *eventMapping = [RKEntityMapping mappingForEntityForName:@"Event" inManagedObjectStore:managedObjectStore];
[eventMapping addAttributeMappingsFromDictionary:@{
 @"id": @"eventId",
 @"name": @"name",
 @"amount": @"amount",
 @"length": @"length",
 @"updated_at": @"updatedAt",
 @"created_at": @"createdAt",
 @"latitude": @"latitude",
 @"longitude": @"longitude",
 @"thumbnail": @"thumbnail",
 @"airTemp": @"airTemp",
 }];
eventMapping.identificationAttributes = @[ @"eventId" ];

//RKRelationshipMapping *eventRelationship = [RKRelationshipMapping relationshipMappingFromKeyPath:@"events"
//                                                                                     toKeyPath:@"events"
//                                                                                   withMapping:eventMapping];
//[eventMapping addPropertyMapping:eventRelationship];

// Register our mappings with the provider
RKResponseDescriptor *responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:eventMapping
                                                                                   pathPattern:nil
                                                                                       keyPath:@"event"
                                                                                   statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
[objectManager addResponseDescriptor:responseDescriptor];

RKEntityMapping *eventRequestMapping = [eventMapping inverseMapping];
RKRequestDescriptor *eventRequestDescriptor = [RKRequestDescriptor requestDescriptorWithMapping:eventRequestMapping
                                                                                    objectClass:[Event class]
                                                                                    rootKeyPath:@"event"
                                                                                                ];
[objectManager addRequestDescriptor:eventRequestDescriptor];
[RKObjectManager sharedManager].requestSerializationMIMEType = RKMIMETypeJSON;

最佳答案

RESTKit 0.20pre6 中有一个错误，即使它是一个对象，它也会将 POST 请求的 HTTP Body 打印到 NSLog 为(null)。我在开发分支中修复了它。 https://github.com/RestKit/RestKit/pull/1139

关于iphone - 使用 RestKit 发布导致发布 nil 对象，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/14351531/