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

Question

I'm using REST APIs to retrieve data from my Firestore DB. I'm forced to use REST API instead of the Firebase SDK since App Clip don't allow to use the latter.
The JSON file is the following: JSON File
And, as text:
{
"name": "projects/myProject/databases/(default)/documents/Brand/rxnBLnp736gqjFBNLxxx",
"fields": {
"descrizione": {
"stringValue": "My project Brand Demo"
},
"descrizione_en": {
"stringValue": "My project Brand Demo"
},
"listaRefsLinea": {
"arrayValue": {
"values": [
{
"referenceValue": "projects/myProject/databases/(default)/documents/Linea/aeeDNuY9xEvRvyM5cxxx"
}
]
}
},
"data_consumption": {
"stringValue": "7xpISf0XxRnfrnUkNxxx"
},
"url_logo": {
"stringValue": "gs://myproject.appspot.com/FCMImages/app-demo-catalogue.png"
},
"web_url": {
"stringValue": "www.mybrand.it"
},
"nome_brand": {
"stringValue": "My project Demo"
}
},
"createTime": "2021-05-19T10:34:51.828685Z",
"updateTime": "2022-05-24T14:03:16.121296Z"
}
And I'm decoding it as follows:
import Foundation
struct BrandResponse : Codable {
let brands : [Brand_Struct]
private enum CodingKeys : String, CodingKey {
case brands = "documents"
}
}
struct StringValue : Codable {
let value : String
private enum CodingKeys : String, CodingKey {
case value = "stringValue"
}
}
struct Brand_Struct : Codable {
let url_logo : String
let web_url : String
let nome_brand : String
let descrizione : String
let listaRefsLinea : [String]
let descrizione_en : String
let data_consumption : String
private enum BrandKeys : String, CodingKey {
case fields
case listaRefsLinea
}
private enum FieldKeys : String, CodingKey {
case url_logo
case web_url
case nome_brand
case descrizione
case listaRefsLinea
case descrizione_en
case data_consumption
}
init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: BrandKeys.self)
let fieldContainer = try container.nestedContainer(keyedBy: FieldKeys.self, forKey: .fields)
//listaRefsLinea = try containerListaRefsLinea_2.decode(ArrayValue.self, forKey: .values).referenceValue
nome_brand = try fieldContainer.decode(StringValue.self, forKey: .nome_brand).value
web_url = try fieldContainer.decode(StringValue.self, forKey: .web_url).value
url_logo = try fieldContainer.decode(StringValue.self, forKey: .url_logo).value
descrizione = try fieldContainer.decode(StringValue.self, forKey: .descrizione).value
descrizione_en = try fieldContainer.decode(StringValue.self, forKey: .descrizione_en).value
data_consumption = try fieldContainer.decode(StringValue.self, forKey: .data_consumption).value
listaRefsLinea = [""] // <-- How to read this??
}
}
My issue is that I'm not being able to read the array inside the field "listaRefsLinea". Any idea on how to achieve that? Also I'm afraid that part of the troubles come from the fact that that's a Document Reference variable and as such does not conform to the Codable protocol.

Answer 1

Well. listaRefsLinea is a custom object just like your StringValue
So add these structs:
// MARK: - ListaRefsLinea
struct ListaRefsLinea: Codable {
let arrayValue: ArrayValue
}
// MARK: - ArrayValue
struct ArrayValue: Codable {
let values: [Value]
}
// MARK: - Value
struct Value: Codable {
let referenceValue: String
}
and in your custom init decode it to this struct, go down the tree until you get the array and map that to a [String]:
listaRefsLinea = try fieldContainer.decode(ListaRefsLinea.self, forKey: .listaRefsLinea)
.arrayValue.values.map{ $0.referenceValue }