Swift Vapor wrong decoding of array of objects - arrays

Question

I'm trying to pass an array of objects inside another object
struct CreationData: Encodable {
enum CodingKeys: String, CodingKey {
case property1
case amount
case participants
case code
}
var property1: String?
var amount: Double?
var tipAmount: Double?
var participants: [Participant]
var currency: Currency
init() {
name = nil
property1 = nil
participants = []
tipAmount = nil
currency = .hryvna
}
func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: CodingKeys.self)
if let name = name {
try container.encode(name, forKey: .name)
}
if let property1 = property1 {
try container.encode(property1, forKey: .property1)
}
if let tipAmount = tipAmount {
try container.encode(tipAmount, forKey: .tipAmount)
}
if !participants.isEmpty {
try container.encode(participants, forKey: .participants)
}
try container.encode(currency, forKey: .currencyCode)
}
}
where object in array is
struct Participant: Hashable, Encodable {
enum CodingKeys: String, CodingKey {
case amount
case id
}
var image: Data?
var displayName: String
var amount: Double? = 100
var id: Int?
var name: String?
var isSelected: Bool = false
func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: CodingKeys.self)
try container.encode(amount, forKey: .amount)
try container.encode(id, forKey: .id)
}
}
so my JSON looks something like this
{
"property1" : 123,
"code" : "zen",
"name" : "No name",
"participants" : [
{
"amount" : 100,
"id" : 1
}
]
}
On the backend I use this handler
func createHandler(_ req: Request, splitCreate: Create) throws -> Future<SplitResponse> {
let logger = try req.make(Logger.self)
let user = try req.requireAuthenticated(User.self)
guard let id = user.id else {
throw Abort(.badRequest, reason: "Couldn't get an id for current user")
}
...
with this request content object
struct Create: Content {
struct Participant: Content {
var id: Int?
var amount: Double?
}
var amount: Double?
var tipAmount: Double?
var name: String?
var participants: [Participant]
var currencyCode: String
}
I create pivots by the participants array, and the problem is that instead of getting a single participant from an array like so
[App.Create.Participant(id: Optional(1), amount: Optional(100.0))]
on the backend from the specified JSON I get these participants
[App.Create.Participant(id: Optional(1), amount: nil), App.Create.Participant(id: Optional(1), amount: Optional(100.0))]
Seems like my array json is being decoded incorrectly, but I'm unable to find a way to fix it

Answer 1

For some reason adding Content-Type header to URLSessionConfiguration.additionalHeaders didn't change the encoding to JSON.
So I had to set Alamofire's request encoding to JSONEncoding.default explicitly.