Question

So I have the following JSON, which I am using together with ObjectMapper and Realm.

{
  "result": [
    {
      "id": 20,
      "types": [
        "now"
      ],
      "url": "/nl/whereto/ezrhgerigerg",
      "categories": [
        {
          "id": 39,
          "name": "Food "
        },
        {
          "id": 21,
          "name": "Varia"
        }
      ]
    },

My problem is getting the data from "types", which for some items in the array says "now" or "later", and is empty for other items (hence, no types item is given).

I tried to do the following in my mapping:

class Publication: Object, Mappable {
    dynamic var id:Int = 0
    var typez  = List<getType>()
    dynamic var url:String?

    required convenience init?(_ map: Map) {
        self.init()
    }

    override static func primaryKey() -> String? {
        return "id"
    }

    func mapping(map: Map) {
        id <- map["id"]
        typez <- map["types"]
        url <- map["url"]
    }
}

class getType: Object, Mappable {
    dynamic var text: String = ""


    required convenience init?(_ map: Map) {
        self.init()
    }

    func mapping(map: Map) {
        text <- map[""]
    }
}

When I check the Realm database, you can see that typez, an array of [getType] was made, but it's empty for all items (even the ones where types is "now"). The other two items (id and url) are filled in in the database.

What am I doing wrong that it won't save to the database?

Answer 1

Because Realm cannot detect assigning List properties since List property is not Objective-C type. So List properties should be declared as let, and should not be nil. You should use append/remove.../insert...method to modifying theList`.

So your code

typez <- map["types"]

doesn't work, since you assign values to the typez property directly.

The workaround is like the following:

func mapping(map: Map) {
    ...
    var typez: [String]? = nil
    typez <- map["types"]

    typez?.forEach { t in
        let obj = getType()
        obj.text = t
        self.typez.append(obj)
    }
    ...

First, store the mapped value to the local variable (it is string array). Then convert the string array to objects. Then append the objects to the List property.

Objectmapper get array of one item within JSON

1 个答案: