Hello All,

I am having trouble with decoding part of the JSON that I get back from the TMDB API. The part that I'm having trouble with is the release_dates. It returns nil from the JSON decoder and I dont know why:

Here is the URL Im using: you'll need an API Key to run it. https://api.themoviedb.org/3/movie/438148?api_key=**YOUR API KEY**&append_to_response=videos,credits,release_dates

Here is the JSON I get back if I put that URL in a browser and run: I'm going to apologize for how long the JSON is. I did shorten it a bit as in took some elements of the arrays out. But I wanted you to see what I get back from the browser, which I will assume is the same thing my app is getting.

{
    "adult": false,
    "backdrop_path": "/nmGWzTLMXy9x7mKd8NKPLmHtWGa.jpg",
    "belongs_to_collection":
    {
        "id": 544669,
        "name": "Minions Collection",
        "poster_path": "/AfYGGvHufd8cIosTvBtnzUExxe4.jpg",
        "backdrop_path": "/62Qe28oi9PaK3P2ljDYUDTGAyST.jpg"
    },
    "budget": 85000000,
    "genres":
    [
        {
            "id": 10751,
            "name": "Family"
        },
        {
            "id": 16,
            "name": "Animation"
        }
    ],
    "homepage": "https://www.minionsmovie.com/",
    "id": 438148,
    "imdb_id": "tt5113044",
    "original_language": "en",
    "original_title": "Minions: The Rise of Gru",
    "overview": "A fanboy of a supervillain supergroup known as the Vicious 6, Gru hatches a plan to become evil enough to join them, with the backup of his followers, the Minions.",
    "popularity": 11087.461,
    "poster_path": "/wKiOkZTN9lUUUNZLmtnwubZYONg.jpg",
    "production_companies":
    [
        {
            "id": 33,
            "logo_path": "/8lvHyhjr8oUKOOy2dKXoALWKdp0.png",
            "name": "Universal Pictures",
            "origin_country": "US"
        },
        {
            "id": 6704,
            "logo_path": "/acf3yqGq8Bm9smHwkQGRDVO5CM5.png",
            "name": "Illumination Entertainment",
            "origin_country": "US"
        }
    ],
    "production_countries":
    [
        {
            "iso_3166_1": "US",
            "name": "United States of America"
        }
    ],
    "release_date": "2022-06-29",
    "revenue": 399884000,
    "runtime": 87,
    "spoken_languages":
    [
        {
            "english_name": "English",
            "iso_639_1": "en",
            "name": "English"
        }
    ],
    "status": "Released",
    "tagline": "A villain will rise.",
    "title": "Minions: The Rise of Gru",
    "video": false,
    "vote_average": 7.6,
    "vote_count": 343,
    "videos":
    {
        "results":
        [
            {
                "iso_639_1": "en",
                "iso_3166_1": "US",
                "name": "Official Trailer 3",
                "key": "HhIl_XJ-OGA",
                "site": "YouTube",
                "size": 1080,
                "type": "Trailer",
                "official": true,
                "published_at": "2022-06-06T15:00:15.000Z",
                "id": "629e8340caa50837e3b31cfd"
            },
            {
                "iso_639_1": "en",
                "iso_3166_1": "US",
                "name": "Official Trailer 2",
                "key": "6DxjJzmYsXo",
                "site": "YouTube",
                "size": 1080,
                "type": "Trailer",
                "official": true,
                "published_at": "2022-03-30T15:00:03.000Z",
                "id": "624487897caa4700476aac08"
            }
        ]
    },
    "credits":
    {
        "cast":
        [
            {
                "adult": false,
                "gender": 2,
                "id": 4495,
                "known_for_department": "Acting",
                "name": "Steve Carell",
                "original_name": "Steve Carell",
                "popularity": 39.287,
                "profile_path": "/dzJtsLspH5Bf8Tvw7OQC47ETNfJ.jpg",
                "cast_id": 6,
                "character": "Gru (voice)",
                "credit_id": "5dec1a93eee18600128b94f8",
                "order": 0
            },
            {
                "adult": false,
                "gender": 2,
                "id": 124747,
                "known_for_department": "Acting",
                "name": "Pierre Coffin",
                "original_name": "Pierre Coffin",
                "popularity": 11.324,
                "profile_path": "/5HojYPP34c4agydy7D90apCMNHn.jpg",
                "cast_id": 0,
                "character": "Kevin / Stuart / Bob / Minions (voice)",
                "credit_id": "588fdb0a92514133a50000f5",
                "order": 1
            }
        ],
        "crew":
        [
            {
                "adult": false,
                "gender": 2,
                "id": 5720,
                "known_for_department": "Production",
                "name": "Christopher Meledandri",
                "original_name": "Christopher Meledandri",
                "popularity": 5.409,
                "profile_path": "/iRcvLhuIzkUkjCR4C3NKbi2juuv.jpg",
                "credit_id": "5e3aea0443250f0015c74505",
                "department": "Production",
                "job": "Producer"
            },
            {
                "adult": false,
                "gender": 0,
                "id": 7963,
                "known_for_department": "Visual Effects",
                "name": "Carter Goodrich",
                "original_name": "Carter Goodrich",
                "popularity": 1.575,
                "profile_path": null,
                "credit_id": "62bf906428723c004c809ff3",
                "department": "Visual Effects",
                "job": "Character Designer"
            }
        ]
    },
    "release_dates":
    {
        "results":
        [
            {
                "iso_3166_1": "BR",
                "release_dates":
                [
                    {
                        "certification": "L",
                        "iso_639_1": null,
                        "note": "",
                        "release_date": "2022-06-30T00:00:00.000Z",
                        "type": 3
                    }
                ]
            },
            {
                "iso_3166_1": "NL",
                "release_dates":
                [
                    {
                        "certification": "",
                        "iso_639_1": "",
                        "note": "",
                        "release_date": "2022-06-29T00:00:00.000Z",
                        "type": 3
                    }
                ]
            }
        ]
    }
}

In my function that loads and decodes it I printed out what I am getting back:

Illumination", site: "YouTube")])), release_dates: nil)

Here is my struct that I'm using: again I apologize for the length, just want you to see everything

struct MovieResponse: Decodable {
    let results: [TMDBMovie]
}

struct TMDBMovie: Decodable, Identifiable, Hashable {
    static func == (lhs: TMDBMovie, rhs: TMDBMovie) -> Bool {
        lhs.id == rhs.id
    }

    func hash(into hasher: inout Hasher) {
        hasher.combine(id)
    }

    var id: Int
    let title: String
    let backdropPath: String?
    let posterPath: String?
    let overview: String
    let voteAverage: Double
    let voteCount: Int
    let runtime: Int?
    let releaseDate: String?

    let genres: [MovieGenre]?
    let credits: MovieCredit?
    let videos: MovieVideoResponse?
    let release_dates: ReleaseDates?

    static private let yearFormatter: DateFormatter = {
        let formatter = DateFormatter()
        formatter.dateFormat = "yyyy"
        return formatter
    }()

    static private let durationFormatter: DateComponentsFormatter = {
        let formatter = DateComponentsFormatter()
        formatter.unitsStyle = .full
        formatter.allowedUnits = [.hour, .minute]
        return formatter
    }()

    var backdropURL: URL {
        return URL(string: "https://image.tmdb.org/t/p/w500\(backdropPath ?? "")")!
    }

    var posterURL: URL {
        return URL(string: "https://image.tmdb.org/t/p/w500\(posterPath ?? "")")!
    }

    var genreText: String {
        genres?.first?.name ?? "n/a"
    }

    var ratingText: String {
        let rating = Int(voteAverage)
        let ratingText = (0..<rating).reduce("") { (acc, _) -> String in
            return acc + "★"
        }
        return ratingText
    }

    var scoreText: String {
        guard ratingText.count > 0 else {
            return "n/a"
        }
        return "\(ratingText.count)/10"
    }

    var yearText: String {
        guard let releaseDate = self.releaseDate, let date = Utilities.dateFormater.date(from: releaseDate) else {
            return "n/a"
        }
        return TMDBMovie.yearFormatter.string(from: date)
    }

    var durationText: String {
        guard let runtime = self.runtime, runtime > 0 else {
            return "n/a"
        }
        return TMDBMovie.durationFormatter.string(from: TimeInterval(runtime) * 60) ?? "n/a"
    }

    var cast: [MovieCast]? {
        credits?.cast
    }

    var crew: [MovieCrew]? {
        credits?.crew
    }

    var directors: [MovieCrew]? {
        crew?.filter { $0.job.lowercased() == "director" }
    }

    var producers: [MovieCrew]? {
        crew?.filter { $0.job.lowercased() == "producer" }
    }

    var screenWriters: [MovieCrew]? {
        crew?.filter { $0.job.lowercased() == "story" }
    }

    var youtubeTrailers: [MovieVideo]? {
        videos?.results.filter { $0.youtubeURL != nil }
    }

    var mpaaRating: String {
        if let releaseDate = release_dates?.results.filter({ $0.iso_3166_1.uppercased() == "US" }) {
            return releaseDate[0].release_dates[0].certification
        }
        return ""
    }
}

// MARK: - Genre
struct MovieGenre: Decodable {
    let name: String
}

// MARK: - Credits (Cast and Crew)
struct MovieCredit: Decodable {
    let cast: [MovieCast]
    let crew: [MovieCrew]
}

struct MovieCast: Decodable, Identifiable {
    let id: Int
    let character: String
    let name: String
}

struct MovieCrew: Decodable, Identifiable {
    let id: Int
    let job: String
    let name: String
}

// MARK: - YouTube Videos
struct MovieVideoResponse: Decodable {
    let results: [MovieVideo]
}

struct MovieVideo: Decodable, Identifiable {
    let id: String
    let key: String
    let name: String
    let site: String

    var youtubeURL: URL? {
        guard site == "YouTube" else {
            return nil
        }
        return URL(string: "https://youtube.com/watch?v=\(key)")
    }
}

// MARK: - Release Dates
struct ReleaseDates: Decodable {
    let results: [ReleaseDatesResult]
}

struct ReleaseDatesResult: Decodable {
    let iso_3166_1: String
    let release_dates: [ReleaseDate]
}

struct ReleaseDate: Decodable {
    let certification: String
}

// Here is the function I use to load and decode
    private func loadURLAndDecode<D: Decodable>(url: URL, params: [String: String]? = nil) async throws -> D {
        guard var urlComponents = URLComponents(url: url, resolvingAgainstBaseURL: false) else {
            throw MovieError.invalidEndpoint
        }

        var queryItems = [URLQueryItem(name: "api_key", value: apiKey)]
        if let params = params {
            queryItems.append(contentsOf: params.map { URLQueryItem(name: $0.key, value: $0.value) })
        }

        urlComponents.queryItems = queryItems

        guard let finalURL = urlComponents.url else {
            throw MovieError.invalidEndpoint
        }

        print("finalURL: \(finalURL)")

        let (data, response) = try await urlSession.data(from: finalURL)
        guard let httpResponse = response as? HTTPURLResponse, 200..<300 ~= httpResponse.statusCode else {
            throw MovieError.invalidResponse
        }

        print("DATA: \(try self.jsonDecoder.decode(D.self, from: data))")
        return try self.jsonDecoder.decode(D.self, from: data)
    }

If anyone can help with this or point out what might be happening I'd appreciate it very much.

Thanks Taz

Hello All,

I figured out my issue, I was using the keyDecodingStrategy = .convertFromSnakeCase and in my TMDBMovie struct i had the following:

let release_dates: ReleaseDates?

struct ReleaseDates: Decodable {
    let results: [ReleaseDatesResult]
}

struct ReleaseDatesResult: Decodable {
    let iso_3166_1: String
    let release_dates: [ReleaseDate]
}

struct ReleaseDate: Decodable {
    let certification: String
}

I just needed to change the snake case to camel case and it all worked. I don't know why forgot that, but I did. I figured instead of deleting this post I'd just add what I was missing and maybe it will help someone else.

Thanks to all who have read this long post. It's a fine line on how much you put in the post as far as code goes, but as I said I just wanted to give as much as possible.

Thanks, Taz

@nemecek-filip

Thanks for the reply, I think I was posting at the same time you were. I changed the solved over to you since you came to the same conclusion that I did. It looks like we were both on the same track.

I figured it out by playing around in a playground. The issue was because I was using two different styles for declaring my properties. I thought that you had to declare them just as they were in the incoming JSON, but after reading about convertFromSnakeCase I realized that was doing it for me automatically. The decoding strategy was declared on the decoder itself.

Anyway, just wanted to say thanks for the reply, Taz