Realm + Object Mapper + SwityJSON

问题

I need help in mapping my object

Realm Model: https://gist.github.com/n1tesh/7d6c6e155285dd6b39c8edba76f6eba5

This is how I'm doing

    // write request result to realm database
    let entries = json["data"]
    realm.beginWrite()
        let entry: ChatGroups = Mapper<ChatGroups>().map(JSONObject: entries)!
        realm.add(entry, update: true)

    do {
        try realm.commitWrite()
    } catch {

    }

JSON Response: https://gist.github.com/n1tesh/bf84cbd930f8c76b340f21723a217ebe

But i'm getting error fatal error: unexpectedly found nil while unwrapping an Optional value

Please help me out with what I'm doing wrong.

回答1:

Create a class to transform Array to List, because the Realm doesn't accept arrays.

import ObjectMapper
import RealmSwift

public class ListTransform<T:RealmSwift.Object> : TransformType where T:Mappable {
    public typealias Object = List<T>
    public typealias JSON = [AnyObject]

    let mapper = Mapper<T>()

    public init(){}

    public func transformFromJSON(_ value: Any?) -> Object? {
        let results = List<T>()
        if let value = value as? [AnyObject] {
            for json in value {
                if let obj = mapper.map(JSONObject: json) {
                    results.append(obj)
                }
            }
        }
        return results
    }

    public func transformToJSON(_ value: Object?) -> JSON? {
        var results = [AnyObject]()
        if let value = value {
            for obj in value {
                let json = mapper.toJSON(obj)
                results.append(json as AnyObject)
            }
        }
        return results
    }
}

Then in your ChatGroups class you have to call the Transform function to make the transformation, make this change:

updated_by              <- map["updated_by"]
members                 <- map["member"]

to this:

updated_by              <- (map["updated_by"], ListTransform<QuorgUser>())
members                 <- (map["member"], ListTransform<GroupMember>())

回答2:

In your ChatGroup class you have declared

dynamic var image: String = ""

but in your response your are getting null in image key of JSON response.

You need to convert your declaration to:

dynamic var image: String? = nil

来源：https://stackoverflow.com/questions/43977399/realm-object-mapper-swityjson

标签

ios

swift

realm

swifty-json