Create a JSON document from NSObject with SwiftyJSON - json

Question

I'm trying to create a JSON array of objects, to manipulate and save in UserPreferences after, like this:
[
{
"id" : "01",
"title" : "Title"
},
{
"id" : "02",
"title": "Title 02"
}
]
this is my NSObject class:
class Item: NSObject {
var _id: String = ""
var _title: String = ""
var id: String {
get {
return _id
}
set {
_id = newValue
}
}
var title: String {
get {
return _title
}
set {
_title = newValue
}
}
}
And I have this code to convert to JSON using SwiftyJson, but I cant make this like a array
var item: [Item] = ["array of itens already setted"]
var json: JSON = JSON([:])
for item in list {
json["id"].string = item.id
json["title"].string = item.title
}
This code return just the last item of array:
{
"id" : "01",
"title" : "Title"
}

Answer 1

Problem lies here , as loop iterates you are setting values in same object.
var item: [Item] = ["array of itens already setted"]
var json: [JSON] = [JSON([:])]. -----> this should be array not just object
for item in list {
json["id"].string = item.id
json["title"].string = item.title
}
instead use this :
var item: [Item] = ["array of itens already setted"]
var json: [JSON] = [JSON([:])]. -----> json array
for item in list {
let jsonTemp: JSON = JSON([:])
jsonTemp["id"].string = item.id
jsonTemp["title"].string = item.title
json.append(jsonTemp)
}
print("[JSON OBJECT Count :: \(json.count), Informations are : \(json)]")

Answer 2

I'd suggest that class Item adopts Codable protocol.
Then have JSONEncoder do the job. That way, you can even nest the resulting JSON inside more complex type.
Also check this out for how to customize key names.
let items = [Item(), Item()]
items[0].id = "01"
items[0].title = "Title"
items[1].id = "02"
items[1].title = "Title 02"
let encoder = JSONEncoder()
encoder.outputFormatting = .prettyPrinted
print(String(data: try encoder.encode(items), encoding: .ascii)!)
/* result
[
{
"_id" : "01",
"_title" : "Title"
},
{
"_id" : "02",
"_title" : "Title 02"
}
]
*/