Failure encoding encodable of type RecentSearches: The operation couldn’t be completed.

[WestFlow127]

I am trying to store a struct that contains two arrays of objects (UserEntity.Fragment & GenreEntity.Fragment).

public struct RecentSearches: MagmaEntity {
   var id: String
   var genres: [MagmaGenreEntity.Fragment]
   var users: [MagmaUserEntity.Fragment]

   public init(
        id: String = Cuid.generateId(),
        users: [MagmaUserEntity.Fragment] = [],
        genres: [MagmaGenreEntity.Fragment] = []
    ) {
        self.id = id
        self.users = users
        self.genres = genres
       }
    }

Both the items in the array who conform to 'Fragment' protocol conforms to Codable & DefaultsSerializable through inheriting 'MagmaEntity'. As well as the Struct 'RecentSearches' itself, conforms to MagmaEntity.

  protocol MagmaEntity: Codable, DefaultsSerializable, Equatable, IdentifiableType {
      var id: String { get }
  }

  extension MagmaEntity {
      public var identity: String {
          id
      }
  }

The struct initializes the the DefaultKey for "RecentSearches", but when it comes time to add a user to the 'users' array, I get an encoding error:

"Fatal error: Failure encoding encodable of type RecentSearches: The operation couldn’t be completed. 

(CodableFirebase.DocumentReferenceError error 0.): file SwiftyUserDefaults/Defaults.swift, line 79"

I've tried writing my own init(encoder:) function and defining my own CodingKeys but that didn't work. Does anyone know what might be my problem? Let me know if any more info is needed for clarification.

[sunshinejr]

hey @WestFlow127, it seems like a problem with encoding the type itself - did you try encoding the type using a simple JSONEncoder?

[WestFlow127]

@sunshinejr I didn't try that. I thought it should work for free with the frameworks. Here is where it fails exactly:

As you can see in the ss, the JSONEncoder is being used within the swiftyDefaults framework. Did you have a different method in mind?

*Update:

I tried implementing my own encode and decode functions as so which did not work:

public struct RecentSearches: MagmaEntity {
    var id: String
    var genres: [MagmaGenreEntity.Fragment]
    var users: [MagmaUserEntity.Fragment]

    enum CodingKeys: String, CodingKey {
        case genres = "genres"
        case users = "users"
        case id = "id"
    }

    public init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        id = try container.decode(String.self, forKey: .id)

        var genresContainer = try container.nestedUnkeyedContainer(forKey: .genres)
        var _genres : [MagmaGenreEntity.Fragment] = []
        while !genresContainer.isAtEnd {
            _genres.append(try genresContainer.decode(MagmaGenreEntity.Fragment.self))
        }
        genres = _genres

        var usersContainer = try container.nestedUnkeyedContainer(forKey: .users)
        var _users : [MagmaUserEntity.Fragment] = []
        while !usersContainer.isAtEnd {
            _users.append(try usersContainer.decode(MagmaUserEntity.Fragment.self))
        }
        users = _users
    }

    public func encode(to encoder: Encoder) throws {
        var container = encoder.container(keyedBy: CodingKeys.self)
        try container.encode(id, forKey: .id)

        var userContainer = container.nestedUnkeyedContainer(forKey: .users)
        for user in users {
            try userContainer.encode(user) // failed here
        }

        var genreContainer = container.nestedUnkeyedContainer(forKey: .genres)
        for genre in genres {
            try genreContainer.encode(genre)
        }
    }
}

[sunshinejr]

@WestFlow127 So the problem seems to be that the JSONEncoder is not able to correctly encode your users. Not sure why is that the case, maybe a bug in Swift? I would advise investigating this more and post a bug at Swift's JIRA (we have reported few regarding generics in SwiftUserDefaults as well...).

Though if you think you are able to encode/decode the type via a different method (e.g. archiving using NSKeyedArchiver), we have few other built-in bridges that could help you with that, or you can even write your own to decode/encode your object from/to Data (since this is how you need to store full objects in plists, unfortunately).