Issue decoding JSON | Swift - swift

Question

I am having an issue dynamically populating the date associated with each section.
The value of grouped is currently derived from grouping the raw JSON data by routeid
You can see that I am currently using a static value for date as a test, while $0.key represent the value of myID dynamically.
How can also add the dynamic value of myDate intead of "test"?
Variables:
var sections = [mySections]()
var structure = [myStructure]()
Currently this is true
sections.map(\.id) == [8,4]
At the end this must be true as well
sections.map(\.date) == [2021-01-20, 2021-01-18]
Decoding:
do {
let decoder = JSONDecoder()
let res = try decoder.decode([myStructure].self, from: data)
let grouped = Dictionary(grouping: res, by: { $0.myID })
_ = grouped.keys.sorted()
sections = grouped.map { mySections(date: "test", id: $0.key, items: $0.value) }
.sorted { $0.id > $1.id }
}
Struct:
struct mySections {
let date : String
let id : Int
var items : [myStructure]
}
struct myStructure: Decodable {
let name: String
let type: String
let myID: Int
let myDate: String
}
Example JSON:
[
{
"name": "Jeff",
"type": "large",
"myID": 8,
"myDate": "2021-01-20"
},
{
"name": "Jessica",
"type": "small",
"myID": 4,
"myDate": "2021-01-18"
},
{
"name": "Beth",
"type": "medium",
"myID": 4,
"myDate": "2021-01-18"
}
]

Answer 1

So, you want it grouped by both id number and date string? I would create a Hashable structure for those two values.
struct Section {
let date: String
let id: Int
var items: [Item]
}
extension Section {
struct Header: Hashable {
let date: String
let id: Int
}
}
struct Item: Decodable {
let name: String
let type: String
let myID: Int
let myDate: String
}
And
let decoder = JSONDecoder()
let res = try decoder.decode([Item].self, from: data)
let sections = Dictionary(grouping: res) { Section.Header(date: $0.myDate, id: $0.myID) }
.sorted { $0.key.id > $1.key.id }
.map { Section(date: $0.key.date, id: $0.key.id, items: $0.value) }