How can I do array mapping with objectmapper?

Question

I have a response model that looks like this:

class ResponseModel: Mappable {

    var data: T?
    var code: Int = 0

    required init?(map: Map) {}

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

If the json-data is not an array it works:

{"code":0,"data":{"id":"2","name":"XXX"}}

but if it is an array, it does not work

{"code":0,"data":[{"id":"2","name":"XXX"},{"id":"3","name":"YYY"}]}

My mapping code;

let apiResponse = Mapper<ResponseModel>().map(JSONObject: response.result.value)

For details; I tried this code using this article : http://oramind.com/rest-client-in-swift-with-promises/

score 15 · Answer 1 · answered Mar 13 '17 at 12:30

15

you need to use mapArray method instead of map :

let apiResponse = Mapper<ResponseModel>().mapArray(JSONObject: response.result.value)

answered Mar 13 '17 at 12:30

MohyG

1,335
13
25

score 4 · Answer 2 · answered Oct 07 '19 at 14:18

What I do is something like this:

func mapping(map: Map) {
    if let _ = try? map.value("data") as [Data] {
       dataArray <- map["data"]
    } else {
       data <- map["data"]
    }

    code <- map["code"]
}

where:

var data: T?
var dataArray: [T]?
var code: Int = 0

The problem with this is that you need to check both data and dataArray for nil values.

score 3 · Accepted Answer · answered Dec 11 '16 at 19:19

3

You need to change your declaration of data to an array, since that's how it is in the JSON:

var data: [T]?

answered Dec 11 '16 at 19:19

Alex S

572
7
15

but data sometimes object sometimes array. is there a way for both? – frontier Dec 11 '16 at 20:28
Create two separate mappable classes, one for an array and one without an array. Try mapping the first one and if it fails try the second one. – Alex S Dec 11 '16 at 20:46
2

Also, the API should really wrap the object in an array object even when there is only one element. – Alex S Dec 11 '16 at 20:47

score 1 · Answer 4 · edited Aug 16 '18 at 07:56

1

let apiResponse = Mapper<ResponseModel>().mapArray(JSONObject: response.result.value)

works for me

edited Aug 16 '18 at 07:56

Giorgos Myrianthous

36,235
20
134
156

answered Aug 16 '18 at 06:25

ioSana

117
2

score 0 · Answer 5 · answered Jan 12 '18 at 17:41

Anyone using SwiftyJSON and if you want an object from JSON directly without having a parent class, for example, you want the "data" from it. You can do something like this,

if let data = response.result.value {
   let json = JSON(data)
   let dataResponse = json["data"].object
   let responseObject = Mapper<DataClassName>().mapArray(JSONObject: dataResponse)
}

This will return you [DataClassName]? as response.

xevser · Answer 6 · 2020-02-27T08:48:06.777

Based on Abrahanfer's answer. I share my solution. I wrote a BaseResult for Alamofire.

class BaseResult<T: Mappable> : Mappable {

var Result : Bool = false
var Error : ErrorResult?
var Index : Int = 0
var Size : Int = 0
var Count : Int = 0
var Data : T?
var DataArray: [T]?

required init?(map: Map){

}

func mapping(map: Map) {
    Result  <- map["Result"]
    Error <- map["Error"]
    Index <- map["Index"]
    Size <- map["Size"]
    Count <- map["Count"]

    if let _ = try? map.value("Data") as [T] {
       DataArray <- map["Data"]
    } else {
       Data <- map["Data"]
    }
}}

The usage for Alamofire :

WebService.shared.request(url, params, encoding: URLEncoding.default, success: { (response : BaseResult<TypeData>) in

            if let arr = response.DataArray
            {
                for year in arr
                {
                   self.years.append(year)
                }
            }
        }, failure: {

        })

The request method is :

 func request<T: Mappable>(_ url: String,_ parameters: [String : Any] = [:], _ method: HTTPMethod = .post,_ httpHeaders: HTTPHeaders? = nil, encoding: ParameterEncoding = JSONEncoding.default, success: @escaping (T) -> Void, failure: @escaping () -> () ) {

    AF.request(newUrl, method:method, parameters:parameters, encoding:encoding, headers: httpHeaders)

    .responseJSON { response in

        if let res = response.value {
            let json = res as! [String: Any]
            if let object = Mapper<T>().map(JSON: json) {
                success(object)
                return
            }
        }else if let _ = response.error {
            failure()
        }
    }
}

And TypeData class is :

class TypeData : Mappable
{
var Id : String = ""
var Title: String =  ""

required init(map: Map){

}

func mapping(map: Map) {
    Id  <- map["ID"]
    Title  <- map["YEAR"]
}}

How can I do array mapping with objectmapper?

6 Answers6