Pistachiargo is a model framework using Argo. It's based on Pistachio.
Carthage is a simple, decentralized dependency manager for Cocoa.
- Add Pistachiargo to your Cartfile:
github "felixjendrusch/Pistachiargo" ~> 0.2
-
Run
carthage updateto fetch and build Pistachiargo and its dependencies.
Like Pistachio, Pistachiargo leverages lenses and value transformers to create type safe adapters. Let's start by defining a very simple model:
struct Origin {
var city: String
init(city: String = "") {
self.city = city
}
}struct Person {
var name: String
var age: Int
var origin: Origin?
var children: [Person]?
init(name: String = "", age: Int = 0, origin: Origin? = nil, children: [Person]? = nil) {
self.name = name
self.age = age
self.origin = origin
self.children = children
}
}A lens is basically just a combination of a getter and a setter, providing a view on your model:
struct OriginLenses {
static let city = Lens(get: { $0.city }, set: { (inout origin: Origin, city) in
origin.city = city
})
}struct PersonLenses {
static let name = Lens(get: { $0.name }, set: { (inout person: Person, name) in
person.name = name
})
static let age = Lens(get: { $0.age }, set: { (inout person: Person, age) in
person.age = age
})
static let origin = Lens(get: { $0.origin }, set: { (inout person: Person, origin) in
person.origin = origin
})
static let children = Lens(get: { $0.children }, set: { (inout person: Person, children) in
person.children = children
})
}However, Pistachiargo ships with a lot of JSON value transformers, convenience functions and a JSON adapter:
struct JSONAdapters {
static let origin = JSONAdapter(specification: [
"city_name": JSONString(OriginLenses.city)
], value: Origin())
static let person = fix { adapter in
return JSONAdapter(specification: [
"name": JSONString(PersonLenses.name),
"age": JSONNumber(PersonLenses.age),
"origin": JSONObject(PersonLenses.origin)(adapter: origin),
"children": JSONArray(PersonLenses.children)(adapter: adapter)
], value: Person())
}
}JSON adapters handle transforming and reverse transforming your models:
let adapter = JSONAdapters.person
var person = Person(name: "Felix", origin: Origin(city: "Berlin"))
var data = adapter.transform(person)
// == .Success(Box(.JSONObject([
// "name": .JSONString("Felix"),
// "age": .JSONNumber(0),
// "origin": .JSONObject([
// "city_name": .JSONString("Berlin")
// ]),
// "children": .JSONNull
// ])))
adapter.reverseTransform(data.value!)
// == .Success(Box(person))Both transform and reverseTransform return a Result, which either holds the (reverse) transformed value or an error. This enables you to gracefully handle transformation errors.
- Working with immutable models in Swift (February 14, 2015)