Retrieve Map from Firebase Firestore using REST API on iOS - ios

Question

I'm trying to retrieve maps values from a Firebase Firestore JSON file. So far I've been able to get any field I wanted but I'm having trouble with maps since they are so nested.
Here you can see an image of the JSON.
And here you can see as text.
"user_metrics": {
"arrayValue": {
"values": [
{
"mapValue": {
"fields": {
"point1": {
"integerValue": "0"
},
"point2": {
"integerValue": "0"
},
"metricDescription": {
"stringValue": "Distanza Pupillare"
},
"metricResult": {
"doubleValue": 6.27
},
"metricDescriptionEn": {
"stringValue": "Distance between pupils"
},
"metricTitle": {
"stringValue": "DBP"
}
}
}
},
And I'm decoding it as follows:
struct SessionResponse : Codable {
let sessions : [Session_Struct]
private enum CodingKeys : String, CodingKey {
case sessions = "documents"
}
}
struct SessionStringValue : Codable {
let value : String
private enum CodingKeys : String, CodingKey {
case value = "stringValue"
}
}
struct Session_Struct : Codable {
let is_first_session : Bool
let device : String
let glassesRefs : [String]
let ref_catalogo : String
let total_time : Double
let data_inizio_sessione : String
let data_fine_user_session : String
let device_id : String
let lineaRefs : [String]
let modelRefs : [String]
let user_metrics : [String]
private enum SessionKeys : String, CodingKey {
case fields
}
private enum FieldKeys : String, CodingKey {
case is_first_session
case device
case glassesRefs
case ref_catalogo
case total_time
case data_inizio_sessione
case data_fine_user_session
case device_id
case lineaRefs
case modelRefs
case user_metrics
}
// MARK: - Total Time
struct TotalTime: Codable {
let doubleValue: Double
}
// MARK: - First Session
struct FirstSession: Codable {
let booleanValue: Bool
}
// MARK: - ListaRefsSizes
struct MapMetrics: Codable {
let arrayValue: MetricsArrayValue
}
// MARK: - ArrayValue
struct MetricsArrayValue: Codable {
let values: [ValueMetric]
}
// MARK: - ArrayValue
struct ValueMetric: Codable {
let mapValue : MapValue
}
// MARK: - ListaRefsSizes
struct ListaRefsGlasses: Codable {
let arrayValue: ArrayValue
}
// MARK: - ArrayValue
struct ArrayValue: Codable {
let values: [Value]
}
// MARK: - Value
struct Value: Codable {
let stringValue: String
}
// MARK: - Value
struct MapValue: Codable {
let mapValue: String
}
// MARK: - Value
struct ReferenceValue: Codable {
let referenceValue: String
}
init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: SessionKeys.self)
let fieldContainer = try container.nestedContainer(keyedBy: FieldKeys.self, forKey: .fields)
is_first_session = try fieldContainer.decode(FirstSession.self, forKey: .is_first_session).booleanValue
device = try fieldContainer.decode(SessionStringValue.self, forKey: .device).value
ref_catalogo = try fieldContainer.decode(ReferenceValue.self, forKey: .ref_catalogo).referenceValue
total_time = try fieldContainer.decode(TotalTime.self, forKey: .total_time).doubleValue
data_inizio_sessione = try fieldContainer.decode(SessionStringValue.self, forKey: .data_inizio_sessione).value
data_fine_user_session = try fieldContainer.decode(SessionStringValue.self, forKey: .data_fine_user_session).value
device_id = try fieldContainer.decode(SessionStringValue.self, forKey: .device_id).value
//Lists
glassesRefs = try fieldContainer.decode(ListaRefsGlasses.self, forKey: .glassesRefs)
.arrayValue.values.map{ $0.stringValue }
lineaRefs = try fieldContainer.decode(ListaRefsGlasses.self, forKey: .lineaRefs)
.arrayValue.values.map{ $0.stringValue }
modelRefs = try fieldContainer.decode(ListaRefsGlasses.self, forKey: .modelRefs)
.arrayValue.values.map{ $0.stringValue }
user_metrics = try fieldContainer.decode(MapMetrics.self, forKey: .user_metrics)
.arrayValue.values.map{ $0.mapValue } // <-- How to read this??
}
}
My issue is that I'm not being able to read the array inside the field "user_metrics". Any idea on how to achieve that? Thanks to anyone who can help!

Answer 1

import Foundation
// MARK: - Welcome
struct Welcome: Codable {
let userMetrics: UserMetrics
enum CodingKeys: String, CodingKey {
case userMetrics = "user_metrics"
}
}
// MARK: - UserMetrics
struct UserMetrics: Codable {
let arrayValue: ArrayValue
}
// MARK: - ArrayValue
struct ArrayValue: Codable {
let values: [Value]
}
// MARK: - Value
struct Value: Codable {
let mapValue: MapValue
}
// MARK: - MapValue
struct MapValue: Codable {
let fields: Fields
}
// MARK: - Fields
struct Fields: Codable {
let point1, point2: Point
let metricDescription: Metric
let metricResult: MetricResult
let metricDescriptionEn, metricTitle: Metric
}
// MARK: - Metric
struct Metric: Codable {
let stringValue: String
}
// MARK: - MetricResult
struct MetricResult: Codable {
let doubleValue: Double
}
// MARK: - Point
struct Point: Codable {
let integerValue: String
}
there is structure for your json
call the api request and get data to Welcome(renamed it as you want)
func requestHTTP(urlString:String,completionHandler:#escaping(_ model:Welcome?,_ error:Error?) -> Void) {
guard let requestUrl = URL(string: urlString) else {return}
URLSession.shared.dataTask(with: requestUrl) { (data, httpUrlResponse, error) in
if(error == nil && data != nil && data?.count != 0) {
do {
let response = try JSONDecoder().decode(Welcome.self, from: data!)
completionHandler(response,nil)
} catch {
debugPrint("error")
completionHandler(nil,error)
}
} else {
completionHandler(nil,error)
}
}.resume()
}
and your will get your data easily
func getDataOnController() {
requestHTTP(urlString: "your url here") { model, error in
if let model = model {
let mapVlues = model.userMetrics.arrayValue.values.map({$0.mapValue})
print(mapVlues)
print(mapVlues.count)
}
}
}