Skip to content

Instantly share code, notes, and snippets.

@mbuchetics
Forked from reckenrode/json.swift
Created June 30, 2017 09:28
Show Gist options
  • Save mbuchetics/c9bc6c22033014aa0c550d3b4324411a to your computer and use it in GitHub Desktop.
Save mbuchetics/c9bc6c22033014aa0c550d3b4324411a to your computer and use it in GitHub Desktop.
Decoding arbitrary JSON with the new Decoder in Swift 4
enum JSON: Decodable {
case bool(Bool)
case double(Double)
case string(String)
indirect case array([JSON])
indirect case dictionary([String: JSON])
init(from decoder: Decoder) throws {
if let container = try? decoder.container(keyedBy: JSONCodingKeys.self) {
self = JSON(from: container)
} else if let container = try? decoder.unkeyedContainer() {
self = JSON(from: container)
} else {
throw DecodingError.dataCorrupted(DecodingError.Context(codingPath: [], debugDescription: ""))
}
}
private init(from container: KeyedDecodingContainer<JSONCodingKeys>) {
var container = container
var dict: [String: JSON] = [:]
for key in container.allKeys {
if let value = try? container.decode(Bool.self, forKey: key) {
dict[key.stringValue] = .bool(value)
} else if let value = try? container.decode(Double.self, forKey: key) {
dict[key.stringValue] = .double(value)
} else if let value = try? container.decode(String.self, forKey: key) {
dict[key.stringValue] = .string(value)
} else if let value = try? container.nestedContainer(keyedBy: JSONCodingKeys.self, forKey: key) {
dict[key.stringValue] = JSON(from: value)
} else if let value = try? container.nestedUnkeyedContainer(forKey: key) {
dict[key.stringValue] = JSON(from: value)
}
}
self = .dictionary(dict)
}
private init(from container: UnkeyedDecodingContainer) {
var container = container
var arr: [JSON] = []
while !container.isAtEnd {
if let value = try? container.decode(Bool.self) {
arr.append(.bool(value))
} else if let value = try? container.decode(Double.self) {
arr.append(.double(value))
} else if let value = try? container.decode(String.self) {
arr.append(.string(value))
} else if let value = try? container.nestedContainer(keyedBy: JSONCodingKeys.self) {
arr.append(JSON(from: value))
} else if let value = try? container.nestedUnkeyedContainer() {
arr.append(JSON(from: value))
}
}
self = .array(arr)
}
}
struct JSONCodingKeys: CodingKey {
var stringValue: String
init?(stringValue: String) {
self.stringValue = stringValue
}
var intValue: Int?
init?(intValue: Int) {
self.init(stringValue: "\(intValue)")
self.intValue = intValue
}
}
@bouk
Copy link

bouk commented Mar 30, 2020

This is missing support for decoding nil values

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment