How can I use Swift’s Codable to encode into a dictionary?

by

If you don’t mind a bit of shifting of data around you could use something like this:

extension Encodable {
  func asDictionary() throws -> [String: Any] {
    let data = try JSONEncoder().encode(self)
    guard let dictionary = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as? [String: Any] else {
      throw NSError()
    }
    return dictionary
  }
}

Or an optional variant

extension Encodable {
  var dictionary: [String: Any]? {
    guard let data = try? JSONEncoder().encode(self) else { return nil }
    return (try? JSONSerialization.jsonObject(with: data, options: .allowFragments)).flatMap { $0 as? [String: Any] }
  }
}

Assuming Foo conforms to Codable or really Encodable then you can do this.

let struct = Foo(a: 1, b: 2)
let dict = try struct.asDictionary()
let optionalDict = struct.dictionary

If you want to go the other way(init(any)), take a look at this Init an object conforming to Codable with a dictionary/array

More Related Contents:

  1. How to use swift 4 Codable in Core Data?
  2. Using Decodable in Swift 4 with Inheritance
  3. What is difference between optional and decodeIfPresent when using Decodable for JSON Parsing?
  4. Using Codable on a dynamic type/object
  5. How can I deal with @objc inference deprecation with #selector() in Swift 4?
  6. How do I use custom keys with Swift 4’s Decodable protocol?
  7. How to convert a date string with optional fractional seconds using Codable in Swift?
  8. Using codable with value that is sometimes an Int and other times a String
  9. How to decode a nested JSON struct with Swift Decodable protocol?
  10. How can I use String substring in Swift 4? ‘substring(to:)’ is deprecated: Please use String slicing subscript with a ‘partial range from’ operator
  11. How to decode a property with type of JSON dictionary in Swift [45] decodable protocol
  12. The use of Swift 3 @objc inference in Swift 4 mode is deprecated?
  13. With JSONDecoder in Swift 4, can missing keys use a default value instead of having to be optional properties?
  14. Swift JSONDecode decoding arrays fails if single element decoding fails
  15. Forced to cast, even if protocol requires given type
  16. Swift Codable multiple types
  17. Value of type ‘StorageMetadata’ has no member ‘downloadURL’
  18. Simultaneous accesses to 0x1c0a7f0f8, but modification requires exclusive access error on Xcode 9 beta 4
  19. Difference between flatMap and compactMap in Swift
  20. Swift 4 JSON Codable – value returned is sometimes an object, others an array
  21. Encode/Decode Array of Types conforming to protocol with JSONEncoder
  22. Swift Codable with dynamic keys
  23. Swift 4 JSON Decodable simplest way to decode type change
  24. Swift 4 Decodable – Dictionary with enum as key
  25. HMAC SHA256 in Swift 4
  26. Compile error in Swift 4 on parameter passing
  27. Generic Swift 4 enum with Void associated type
  28. In Swift 4, how do I remove a block-based KVO observer?
  29. AnyObject and Any in Swift
  30. How String Comparison happens in Swift

Leave a Comment