Transformers is a framework to transform things elegantly using the power of Swift programming language.

Note: Support Swift version: 4.1 or newer

• Cast JSON data with type.
• Cast a swift dictionary to swift model which confirms Codable protocol.
• Cast a swift array whose item type is dictionary to swift model array whose items confirm Codable protocol.

Download the project, and drag the Core folder to your project.

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github "webfrogs/Transformers" ~> 1.0

dependencies: [
    .package(url: "https://github.com/webfrogs/Transformers.git", .upToNextMinor(from: "1.0.0")),
]

The most common scene in iOS programming is handle JSON data.

let jsonString = """
{"key1": "value2"}
"""
let value1: String? = jsonString.data(using: String.Encoding.utf8)
    .flatMap({$0.toDictionary()})
    .flatMap({$0.value(key: "key1")})
print(value1 ?? "")

If you also use RxSwift in your project. Transformers can be easily integrated with RxSwift, and there is no need to transform JSON data fetched from http server to a model manually. All you have to do is define a model which confirms Codable protocol and use Transformers with the map function provided by RxSwift.

Here is a demo code:

struct GithubAPIResult: Codable {
    let userUrl: String
    let issueUrl: String

    enum CodingKeys: String, CodingKey {
        case userUrl = "user_url"
        case issueUrl = "issues_url"
    }
}

let request = URLRequest(url: URL(string: "https://api.github.com")!)
let apiResult: Observable<GithubAPIResult> = URLSession.shared
    .rx.data(request: request)
    .map(Data.jsonToModelHandler)
apiResult.subscribe(onNext: { (result) in
    print(result)
}).disposed(by: kDisposeBag)