Convert JSON to Swift objects. The Objective-C counterpart can be found here: JSONJoy.
Parsing JSON in Swift has be likened to a trip through Mordor, then JSONJoy would be using eagles for that trip.
The release of Swift 4 brought support for the new Codable protocol. This renders most of JSONJoy unneccessary and thus will be deprecated. Version 3.0.2 has been update to support Swift 4 as a means of backward compatibility, but I would encourage the adoption of the new Codable protocol. I wrote a post about it here
First thing is to import the framework. See the Installation instructions on how to add the framework to your project.
import JSONJoyFirst here is some example JSON we have to parse.
{
"id" : 1,
"first_name": "John",
"last_name": "Smith",
"age": 25,
"address": {
"id": 1,
"street_address": "2nd Street",
"city": "Bakersfield",
"state": "CA",
"postal_code": 93309
}
}We want to translate that JSON to these Swift objects:
struct Address {
let objID: Int?
let streetAddress: String?
let city: String?
let state: String?
let postalCode: String?
init() {
}
}
struct User {
let objID: Int?
let firstName: String?
let lastName: String?
let age: Int?
let address = Address()
init() {
}
}Normally this would put us in a validation nightmare:
var user = User()
var error: NSError?
var response: AnyObject? = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions(), error: &error)
if let userDict = response as? NSDictionary {
if let addressDict = userDict["address"] as? NSDictionary {
user.address.city = addressDict["city"] as? String
user.address.streetAddress = addressDict["street_address"] as? String
//etc, etc
}
user.firstName = userDict["first_name"] as? String
user.lastName = userDict["last_name"] as? String
//etc, etc
}
JSONJoy makes this much simpler. We have our Swift objects implement the JSONJoy protocol:
struct Address : JSONJoy {
let objID: Int
let streetAddress: String
let city: String
let state: String
let postalCode: String
let streetTwo: String?
init(_ decoder: JSONLoader) throws {
objID = try decoder["id"].get()
streetAddress = try decoder["street_address"].get()
city = try decoder["city"].get()
state = try decoder["state"].get()
postalCode = try decoder["postal_code"].get()
streetTwo = decoder["street_two"].getOptional()
//just an example of "checking" for a property.
if let meta: String = decoder["meta"].getOptional() {
print("found some meta info: \(meta)")
}
}
}
struct User : JSONJoy {
let objID: Int
let firstName: String
let lastName: String
let age: Int
let address: Address
let addresses: [Address]
init(_ decoder: JSONLoader) throws {
objID = try decoder["id"].get()
firstName = try decoder["first_name"].get()
lastName = try decoder["last_name"].get()
age = try decoder["age"].get()
address = try Address(decoder["address"])
addresses = try decoder["addresses"].get() //infers the type and returns a valid array
}
}Then when we get the JSON back:
do {
var user = try User(JSONLoader(data))
println("city is: \(user.address.city)")
//That's it! The object has all the appropriate properties mapped.
} catch {
print("unable to parse the JSON")
}This also has automatic optional validation like most Swift JSON libraries.
//some randomly incorrect key. This will work fine and the property will just be nil.
firstName = decoder[5]["wrongKey"]["MoreWrong"].getOptional()
//firstName is nil, but no crashing!If you to extend a standard Foundation type (you probably won't need to though)
extension UInt64: JSONBasicType {}This can be combined with SwiftHTTP to make API interaction really clean and easy.
https://github.com/daltoniam/SwiftHTTP#clientserver-example
JSONJoy requires at least iOS 7/OSX 10.10 or above.
Add the project as a dependency to your Package.swift:
import PackageDescription
let package = Package(
name: "YourProject",
dependencies: [
.Package(url: "https://github.com/daltoniam/JSONJoy-Swift", majorVersion: 3)
]
)Check out Get Started tab on cocoapods.org.
To use JSONJoy-Swift in your project add the following 'Podfile' to your project
source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '8.0'
use_frameworks!
pod 'JSONJoy-Swift', '~> 3.0.2'
Then run:
pod install
Check out the Carthage docs on how to add a install. The JSONJoy framework is already setup with shared schemes.
You can install Carthage with Homebrew using the following command:
$ brew update
$ brew install carthageTo integrate JSONJoy into your Xcode project using Carthage, specify it in your Cartfile:
github "daltoniam/JSONJoy-Swift" >= 3.0.2
First see the installation docs for how to install Rogue.
To install JSONJoy run the command below in the directory you created the rogue file.
rogue add https://github.com/daltoniam/JSONJoy-Swift
Next open the libs folder and add the JSONJoy.xcodeproj to your Xcode project. Once that is complete, in your "Build Phases" add the JSONJoy.framework to your "Link Binary with Libraries" phase. Make sure to add the libs folder to your .gitignore file.
Simply grab the framework (either via git submodule or another package manager).
Add the JSONJoy.xcodeproj to your Xcode project. Once that is complete, in your "Build Phases" add the JSONJoy.framework to your "Link Binary with Libraries" phase.
If you are running this in an OSX app or on a physical iOS device you will need to make sure you add the JSONJoy.framework included in your app bundle. To do this, in Xcode, navigate to the target configuration window by clicking on the blue project icon, and selecting the application target under the "Targets" heading in the sidebar. In the tab bar at the top of that window, open the "Build Phases" panel. Expand the "Link Binary with Libraries" group, and add JSONJoy.framework. Click on the + button at the top left of the panel and select "New Copy Files Phase". Rename this new phase to "Copy Frameworks", set the "Destination" to "Frameworks", and add JSONJoy.framework.
- Add Unit Tests
JSONJoy is licensed under the Apache v2 License.