How to map the nested data in a document from Firestore by Swift? - swift

Question

I have a document data structure on Firestore like this:
pic1
pic2
So there are 2 map-objects inside the document and a collection and a another document inside this document
Then I create 3 model swift files for this document
task:
struct task {
var Name: String
var Address: String
var Car: CarModel
car Price: PriceModel
var dictionary: [String:Any] {
return [
"Name" : Name,
"Address" : Address,
"Car" : CarModel,
"Price" : PriceModel
]
}
init?(data: [String:Any]) {
guard let Name = dictionary["Name"] as? String,
let Address = dictionary["Address"] as? String,
let Car = ditionary["car"] as? CarModel,
let Price = dictionary["price"] as? PriceModel else{
return nil
}
self.Name = Name
self.Address = Address
self.Car = Car
self.Price = Price
}
}
CarModel:
struct CarModel {
var brand: String
var model: String
var year: String
var dictionary: [String:Any] {
return [
"brand" : brand,
"model" : model,
"year" : year,
]
}
init?(data: [String:Any]) {
guard let brand = dictionary["brand"] as? String,
let model = dictionary["model"] as? String,
let year = ditionary["year"] as? String else{
return nil
}
self.brand = brand
self.model = model
self.year = year
}
}
PriceModel:
struct PriceModel {
var basic: Int
var extra: Int
var dictionary: [String:Any] {
return [
"basic" : basic,
"extra" : extra,
]
}
init?(data: [String:Any]) {
guard let basic = dictionary["basic"] as? Int,
let extra = ditionary["extra"] as? Int else{
return nil
}
self.basic = basic
self.extra = extra
}
}
Then download the data with this following code:
func loadDataFromFirestore(completion: #escaping (Bool) -> ()) {
var success: Bool = false
DispatchQueue.global(qos: .userInteractive).async {
let downloadGroup = DispatchGroup()
let colRef = db.collection("tasks")
downloadGroup.enter()
colRef.getDocuments() { (querySnapshot, error) in
if let error = error {
print("Error: \(error)")
return
}
for document in querySnapshot!.documents{
let result = document.data()
print (result)
if let data = task(data: result){
print(data)
}
}
success = true
downloadGroup.leave()
}
downloadGroup.wait()
DispatchQueue.main.async {
completion(success)
}
}
}
I can get the data with comment the CarModel and PriceModel, but if I uncomment these two, it will let my app crash!
So how could I get the map-object to adapt to my code?
And the second question is: How can I get the document inside a document's collection with this kind of code?