How to read a subsection from a firebase database - objective-c

Question

I am using this code to access a Firebase Database, but I am cannot figure out how to read the sub array of strings. (the JSON structure is below)). The code I have returns the top level items, but not the list of strings. Would someone be able to assist with this issue?
Here is my function to read from the DB:
func sizes(userId: String = Auth.auth().currentUser!.uid, success: #escaping ([Sizes]) -> ()) {
let ref = Router.sizes.reference()
let query = ref.queryOrdered(byChild: "name") //userId)
query.observe(.value, with: { snapshot in
var array = [Sizes]()
for child in snapshot.children {
if let size = Mapper<Sizes>().map(JSON: (child as! DataSnapshot).value as! [String : AnyObject]) {
array.append(size)
}
}
success(array)
})
}
My Firebase JSON is as follows:
{
"-SzCat_001": {
"name": "Womans",
"sizeCategories": {
"name": "Pants",
"sizeDescriptor": [
"00",
"0",
"2",
"4",
"6",
"8",
"10",
"12",
"XL"
]
}
}
}
And this is what I get returned?
[0] = {
name = "Womans"
sizeCategories = 0 values {} }
I am trying to figure out how to read the sizeCategories list of strings as a subarray of sizes.
Here is my definition of sizes and sizeCategories:
struct Sizes: Mappable {
var name: String = ""
var sizeCategories = [SizeCategories]()
init() {
}
init?(map: Map) {
}
mutating func mapping(map: Map) {
name <- map["name"]
sizeCategories <- map["sizeCategories"]
}
}
struct SizeCategories: Mappable {
var name: String = ""
var sizeDescriptor = [String]()
init() {
}
init?(map: Map) {
}
mutating func mapping(map: Map) {
name <- map["name"]
sizeDescriptor <- map["sizeDescriptor"]
}
}
Thanks for any help!!!

Answer 1

You're jumping through a lot of hoops to read the data here. You could just let allMyData = snapshot.value as! [String: AnyObject] and know that each internal value is also a [String: AnyObject]. But if you really want to destructure into something more typed with this mapping technique, have a look at your sizes definition:
var sizeCategories = [SizeCategories]()
This says "sizeCategories is an array of SizeCategories type". But your data is not structured as an array, it is a dict:
"sizeCategories": {
"name": "Pants",
"sizeDescriptor": [
"00",
"0",
"2",
"4",
"6",
"8",
"10",
"12",
"XL"
]
}
You need to adjust your definition and mapping method here for this field.