How to parse a single JSON array of objects? - ios

Question

I'm calling the API endpoint and the JSON response looks like this:
{
"id": 299536,
"cast": [
{
"cast_id": 1,
"character": "Tony Stark / Iron Man",
"credit_id": "54a9cfa29251414d5b00553d",
"gender": 2,
"id": 3223,
"name": "Robert Downey Jr.",
"order": 0,
"profile_path": "/1YjdSym1jTG7xjHSI0yGGWEsw5i.jpg"
},
{
"cast_id": 6,
"character": "Thor Odinson",
"credit_id": "54a9d012c3a3680c29005762",
"gender": 2,
"id": 74568,
"name": "Chris Hemsworth",
"order": 1,
"profile_path": "/lrhth7yK9p3vy6p7AabDUM1THKl.jpg"
},
{
"cast_id": 13,
"character": "Bruce Banner / Hulk",
"credit_id": "573fc00592514177ec00010a",
"gender": 2,
"id": 103,
"name": "Mark Ruffalo",
"order": 2,
"profile_path": "/isQ747u0MU8U9gdsNlPngjABclH.jpg"
}
]
This is the struct that I've made for the codable protocol.
struct MovieCast: Codable {
let id: Int
let cast: [Cast]
let crew: [Crew]
}
struct Cast: Codable {
let castID: Int
let character, creditID: String
let gender, id: Int
let name: String
let order: Int
let profilePath: String?
enum CodingKeys: String, CodingKey {
case castID = "cast_id"
case character
case creditID = "credit_id"
case gender, id, name, order
case profilePath = "profile_path"
}
}
struct Crew: Codable {
let creditID: String
let department: Department
let gender, id: Int
let job, name: String
let profilePath: String?
enum CodingKeys: String, CodingKey {
case creditID = "credit_id"
case department, gender, id, job, name
case profilePath = "profile_path"
}
}
enum Department: String, Codable {
case art = "Art"
case camera = "Camera"
case costumeMakeUp = "Costume & Make-Up"
case crew = "Crew"
case directing = "Directing"
case editing = "Editing"
case lighting = "Lighting"
case production = "Production"
case sound = "Sound"
case visualEffects = "Visual Effects"
case writing = "Writing"
}
My question is, how can I loop through the objects in a single array using Swift 4? I am using Decodable protocol and have struct that looks like this: (note that I let out some of the json response properties above so the snippet wouldn't be too long)
My goal is to get the
profile_path
out of every object and append it to the array of Strings.

Answer 1

After you get the response try this code in viewDidLoad()
if let dict = response.result.value as? [string:Anyobject]() //fetching the response
if let innerdict = dict["cast"] as? [[string:Anyobject]]()
for cast in innerdict {
if let profile_path = cast[ "profile_path"] as? String
print("profile_path") // to check the profilepath
}
// this is it to get the profile path then append it in the array of type string

Answer 2

Your MovieCast struct contains 2 arrays, one of Cast objects and one of Crew objects.
You could create a protocol Staff that has the shared properties from both (gender, name, profilePath), declare that both types conform to that protocol, and then combine your arrays of Cast and Crew objects into an array of Staff.
Then you could map the resulting array to an array of strings from the profilePath values of each entry in the array:
protocol Staff {
var gender: Int { get }
var name: String { get }
var profilePath: String? { get }
}
Change Cast and Crew like this:
struct Cast: Codable & Staff
struct Crew: Codable & Staff
if you have a crew:
var movieCrew: MovieCast
//Code to load a moview crew
Then
let castAndCrew = (movieCrew.cast as [Staff]) + ((movieCrew.crew as [Staff]?) ?? [])
let allProfilePaths = castAndCrew.compactMap { $0.profilePath }
(Note that I typed this into the SO editor, and my syntax is rarely perfect "out of the gate." It will likely need some minor cleanup.)