JASON: a faster JSON deserializer written in Swift

JASON is a faster JSON deserializer written in Swift.

JASON is the best framework we found to manage JSON at Swapcard. This is by far the fastest and
the most convenient out there, it made our code clearer and improved the global performance
of the app when dealing with large amount of data.

Gautier Gédoux, lead iOS developer at Swapcard

Features

• [x] Very fast - benchmarks
• [x] Fully tested
• [x] Fully documented

• [x] Clean code
• [x] Beautiful API
• [x] Regular updates

• [x] Support for iOS, OSX, tvOS, watchOS
• [x] Compatible with Carthage / CocoaPods
• [x] Provide extensions - Extensions/

Usage

Initialization

let json = JSON(anything) // where `anything` is `AnyObject?`

If you're using Alamofire, include JASON+Alamofire.swift in your project for even more awesomeness:

Alamofire.request(.GET, peopleURL).responseJASON { response in
    if let json = response.result.value {
        let people = json.map(Person.init)
        print("people: \(people)")
    }
}

If you're using Moya, check out Moya-JASON!

Parsing

Use subscripts to parse the JSON object:

json["people"][0]["name"]

// Or with a path:

json[path: "people", 0, "name"]

Type casting

Cast JSON value to its appropriate type by using the computed property json.<type>:

let name = json["name"].string // the name as String?

The non-optional variant json.<type>Value will return a default value if not present/convertible:

let name = json["wrong"].stringValue // the name will be ""

You can also access the internal value as AnyObject? if you want to cast it yourself:

let something = json["something"].object

See the References section for the full list of properties.

JSONKey:

This idea is stolen from SwiftyUserDefaults by Radek Pietruszewski (GitHub, Twitter, Blog).


I can't recommend enough to read his article about it! :boom: Statically-typed NSUserDefaults :boom:

Define and use your JSONKey as follow:

// With a int key:

let personKey = JSONKey<JSON>(0)
let personJSON = peopleJSON[personKey]

// With a string key:

let nameKey = JSONKey<String>("name")
let name = personJSON[nameKey]

// With a path:

let twitterURLKey = JSONKey<NSURL?>(path: 0, "twitter")
let twitterURL = peopleJSON[twitterURLKey]

You might find more convenient to extend JSONKeys as shown in the Example section.

See the References section for the full list of JSONKey types.

Third-party libraries:

• DroidsOnRoids/Moya-JASON JASON bindings for Moya.

Example

This example uses the Dribbble API (docs).


An example of the server response can be found in Tests/Supporting Files/shots.json

• Step 1: Extend JSONKeys to define your JSONKey

JSON.dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"

extension JSONKeys {
    static let id    = JSONKey<Int>("id")
    static let createdAt = JSONKey<NSDate?>("created_at")
    static let updatedAt = JSONKey<NSDate?>("updated_at")

    static let title = JSONKey<String>("title")

    static let normalImageURL = JSONKey<NSURL?>(path: "images", "normal")
    static let hidpiImageURL  = JSONKey<NSURL?>(path: "images", "hidpi")

    static let user = JSONKey<JSON>("user")
    static let name = JSONKey<String>("name")
}

• Step 2: Create the Shot and User models

struct Shot {
    let id: Int
    let title: String

    let normalImageURL: NSURL
    var hidpiImageURL: NSURL?

    let createdAt: NSDate
    let updatedAt: NSDate

    let user: User

    init(_ json: JSON) {
        id    = json[.id]
        title = json[.title]

        normalImageURL = json[.normalImageURL]!
        hidpiImageURL  = json[.hidpiImageURL]

        createdAt = json[.createdAt]!
        updatedAt = json[.updatedAt]!

        user = User(json[.user])
    }
}

struct User {
    let id: Int
    let name: String

    let createdAt: NSDate
    let updatedAt: NSDate

    init(_ json: JSON) {
        id   = json[.id]
        name = json[.name]

        createdAt = json[.createdAt]!
        updatedAt = json[.updatedAt]!
    }
}

• Step 3: Use the JASON+Alamofire.swift extension to fetch the shots

Alamofire.request(.GET, shotsURL).responseJASON { response in
    if let json = response.result.value {
        let shots = json.map(Shot.init)
    }
}

References

Include JASON+Properties.swift for even more types!

Configure JSON.dateFormatter if needed for nsDate parsing

Installation

Carthage

Carthage is a decentralized dependency manager that automates the process of adding frameworks to your Cocoa application.

You can install Carthage with Homebrew using the following command:

$ brew update
$ brew install carthage

To integrate JASON into your Xcode project using Carthage, specify it in your Cartfile:

github "delba/JASON" >= 3.0

CocoaPods

CocoaPods is a dependency manager for Cocoa projects.

You can install it with the following command:

$ gem install cocoapods

To integrate JASON into your Xcode project using CocoaPods, specify it in your Podfile:

use_frameworks!

pod 'JASON', '~> 3.0'

License

Copyright (c) 2015-2019 Damien (http://delba.io)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

GitHub

https://github.com/delba/JASON