BottleRocket

An experimental CLI tool for generating normalized Swift models from example JSON responses.

Goals

• Generate Swift models that don't need any cleanup by hand
• Allow parsing partial JSON responses into the same model
  • Properties that don't show up in every model are optional
• Generated Swift JSON parsing code without dependencies
• Experiment with functional programming techniques in Swift

Installation

• Download project
• Open BottleRocket.xcodeproj
• Build
• Should be installed in /usr/local/bin

Example

Suppose you have two different endpoints that return JSON:

http://myservice.com/api/events

{
  "title": "Birthday party",
  "likes": 12,
  "is_public": true,
  "users": [
    {
      "name": "Sam",
      "id": 1
    },
    {
      "name": "Zoey",
      "id": 2
    }
  ]
}

http://myservice.com/api/user/1

{
  "name": "Sam",
  "age": 28,
  "id": 1,
  "horoscope": "gemini"
}

You can save both sample responses into two files: events.json and user.json. Then run:

$ bottlerocket gen ~/path/to/models

Which then generates two different models:

final class Event: NSCoding {
  let title: String
  let likes: NSNumber
  let is_public: Bool
  let users: [User]

  init(title: String, likes: NSNumber, is_public: Bool, users: [User]) {
    // ...
  }

  convenience init?(json: [String: Any]) {
    // unpack and parse models
    // call designated init
  }

  // encode/decode
}

final class User: NSCoding {
  let name: String
  let id: NSNumber

  // only shows up in api/user/1 response
  let age: NSNumber?
  let horoscope: String?

  // init, json, coding, etc
}

Dependencies

• InflectorKit to convert plural keys into singular classnames
• SwiftCLI because this is my first CLI app