Question

我需要使用一些mapper（例如Object Mapper）将检索到的JSON Object保存到Core Data中。我使用了一个可以检索这个json的rest api：

[
{
    "event_id": "1",
    "event_name": "Lungo il tevere",
    "event_image_url": "https:\/\/www.dayroma.it\/wp-content\/uploads\/2016\/06\/event_fb-9400.jpg",
    "event_content": "<b>Lungo il Tevere Roma 2016, bancarelle sulle banchine del Tevere<\/b>\r\n\r\n&nbsp;\r\n\r\n&nbsp;",
    "event_start_date": "2016-07-29",
    "event_end_date": "2016-07-30",
    "event_start_time": "22:00:00",
    "event_end_time": "03:00:00",
    "location_name": "Lungotevere",
    "location_address": "Piazza Navona 2, Roma",
    "location_latitude": "41.897785",
    "location_longitude": "12.472971"
},
{
    "event_id": "8",
    "event_name": "test 7 - VIlla BOrghese",
    "event_image_url": "https:\/\/www.dayroma.it\/wp-content\/uploads\/2016\/06\/event_fb-9398.jpg",
    "event_content": "TEst villa borghese",
    "event_start_date": "2016-07-29",
    "event_end_date": "2016-07-30",
    "event_start_time": "22:00:00",
    "event_end_time": "02:00:00",
    "location_name": "Villa Borghese",
    "location_address": "Villa Borghese 4, Roma",
    "location_latitude": "41.912888",
    "location_longitude": "12.485208"
}

没什么特别的，一个简单的JSON数组。我需要将其解析为数据对象并存储到Core Data中。实际上，我有关于将Object映射到Core Data Object的问题，因为只检索String值，其他的都是nil。

这是我的dataController

class DataController: NSObject {

var managedObjectContext: NSManagedObjectContext

override  init() {
    // This resource is the same name as your xcdatamodeld contained in your project.
    guard let modelURL = NSBundle.mainBundle().URLForResource("DataModel", withExtension:"momd") else {
        fatalError("Error loading model from bundle")
    }
    // The managed object model for the application. It is a fatal error for the application not to be able to find and load its model.
    guard let mom = NSManagedObjectModel(contentsOfURL: modelURL) else {
        fatalError("Error initializing mom from: \(modelURL)")
    }
    let psc = NSPersistentStoreCoordinator(managedObjectModel: mom)
    self.managedObjectContext = NSManagedObjectContext(concurrencyType: .MainQueueConcurrencyType)
    self.managedObjectContext.persistentStoreCoordinator = psc

    let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
    let docURL = urls[urls.endIndex-1]
    /* The directory the application uses to store the Core Data store file.
     This code uses a file named "DataModel.sqlite" in the application's documents directory.
     */
    let storeURL = docURL.URLByAppendingPathComponent("DataModel.sqlite")
    do {
        try psc.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: storeURL, options: nil)
    } catch {
        fatalError("Error migrating store: \(error)")
    }

}

}

这是我的对象核心属性：

extension Event {

@NSManaged var eventId: Int
@NSManaged var eventName: String?
@NSManaged var eventImageUrl: String?
@NSManaged var eventContent: String?
@NSManaged var eventStartTime: NSDate?
@NSManaged var eventEndTime: NSDate?
@NSManaged var eventStartDate: NSDate?
@NSManaged var eventEndDate: NSDate?
@NSManaged var locationName: String?
@NSManaged var locationAddress: String?
@NSManaged var locationLatitude: NSNumber?
@NSManaged var locationLongitude: NSNumber?

}

这是我实现mappable的核心数据对象模型：

class Event: NSManagedObject, Mappable {


override init(entity: NSEntityDescription, insertIntoManagedObjectContext context: NSManagedObjectContext?) {
    super.init(entity: entity, insertIntoManagedObjectContext: DataController().managedObjectContext)
}

required init?(_ map: Map) {
    let ctx = DataController().managedObjectContext
    let entity = NSEntityDescription.entityForName("Event", inManagedObjectContext: ctx)
    super.init(entity: entity!, insertIntoManagedObjectContext: ctx)

    mapping(map)
}

func mapping(map: Map) {

    eventId   <- map["event_id"]
    eventName   <- map["event_name"]
    eventImageUrl   <- map["event_image_url"]
    eventContent   <- map["event_content"]
    eventStartTime   <- map["event_start_time"]
    eventEndTime   <- map["event_end_time"]
    eventStartDate   <- map["event_start_date"]
    eventEndDate   <- map["event_end_date"]
    locationName   <- map["location_name"]
    locationAddress   <- map["location_address"]
    locationLatitude   <- map["location_latitude"]
    locationLongitude   <- map["location_longitude"]



}

}

运行此：

let URL = "##### MY API ######"
    Alamofire.request(.GET, URL).responseArray { (response: Response<[Event], NSError>) in

        let eventsArray = response.result.value

        for element in eventsArray! {
            print(element)
        }

    }

我找回了这个：

data: {
eventContent = "TEst villa borghese";
eventEndDate = nil;
eventEndTime = nil;
eventId = 0;
eventImageUrl = "https://www.dayroma.it/wp-content/uploads/2016/06/event_fb-9398.jpg";
eventName = nil;
eventStartDate = nil;
eventStartTime = nil;
locationAddress = "Villa Borghese 4, Roma";
locationLatitude = nil;
locationLongitude = nil;
locationName = "Villa Borghese";

}

大部分领域都是零，你能帮我理解是什么问题吗？

谢谢你

Answer 1

即使你在等待NSNumber或NSDate，你也只能收到Json。

要使此地图有效，您应该使用ObjectMapper中的自定义变换，并按照以下方式设置映射：

birthday    <- (map["birthday"], DateTransform())

或进行自定义转换，例如：

private static let formatter: NSNumberFormatter = NSNumberFormatter()
private let transform = TransformOf<NSNumber, String>(fromJSON:
        { (value: String?) -> NSNumber? in
            // transform value from String? to Int?
            formatter.numberStyle = .DecimalStyle
            return formatter.numberFromString(value!)
    }, toJSON:
        { (value: NSNumber?) -> String? in
            // transform value from Int? to String?
            if let value = value
            {
                return String(value)
            }
            return nil
})

并使用它：

people <- (map["people"], transform)

希望得到这个帮助。

对象映射器/核心数据，对象映射器零值字段

1 个答案: