infinum / Japx
Programming Languages
Japx - JSON:API Decoder/Encoder
Lightweight JSON:API parser that flattens complex JSON:API structure and turns it into simple JSON and vice versa.
It works by transferring Dictionary to Dictionary, so you can use Codable, Unbox, Wrap, ObjectMapper or any other object mapping tool that you prefer.
Basic example
For given example of JSON object:
{
"data": {
"id": "1",
"type": "users",
"attributes": {
"email": "[email protected]",
"username": "john"
}
}
}
to parse it to simple JSON use:
let jsonApiObject: [String: Any] = ...
let simpleObject: [String: Any]
do {
simpleObject = try Japx.Decoder.jsonObject(withJSONAPIObject: jsonApiObject)
} catch {
print(error)
}
and parser will convert it to object where all properties inside attributes object will be flattened to the root of data object:
{
"data": {
"email": "[email protected]",
"id": "1",
"username": "john",
"type": "users"
}
}
Advanced examples
Parsing relationships
Simple Article object which has its Author:
{
"data": [
{
"type": "articles",
"id": "1",
"attributes": {
"title": "JSON API paints my bikeshed!",
"body": "The shortest article. Ever.",
"created": "2015-05-22T14:56:29.000Z",
"updated": "2015-05-22T14:56:28.000Z"
},
"relationships": {
"author": {
"data": {
"id": "42",
"type": "people"
}
}
}
}
],
"included": [
{
"type": "people",
"id": "42",
"attributes": {
"name": "John",
"age": 80,
"gender": "male"
}
}
]
}
will be flattened to:
{
"data": [
{
"updated": "2015-05-22T14:56:28.000Z",
"author": {
"age": 80,
"id": "42",
"gender": "male",
"type": "people",
"name": "John"
},
"id": "1",
"title": "JSON API paints my bikeshed!",
"created": "2015-05-22T14:56:29.000Z",
"type": "articles",
"body": "The shortest article. Ever."
}
]
}
Parsing additional information
All nested object which do not have keys defined in JSON:API Specification will be left inside root object intact (same goes for links and meta objects):
{
"data": [
{
"type": "articles",
"id": "3",
"attributes": {
"title": "JSON API paints my bikeshed!",
"body": "The shortest article. Ever.",
"created": "2015-05-22T14:56:29.000Z",
"updated": "2015-05-22T14:56:28.000Z"
}
}
],
"meta": {
"total-pages": 13
},
"links": {
"self": "http://example.com/articles?page[number]=3&page[size]=1",
"first": "http://example.com/articles?page[number]=1&page[size]=1",
"prev": "http://example.com/articles?page[number]=2&page[size]=1",
"next": "http://example.com/articles?page[number]=4&page[size]=1",
"last": "http://example.com/articles?page[number]=13&page[size]=1"
},
"additional": {
"info": "My custom info"
}
}
Parsed JSON:
{
"data": [
{
"updated": "2015-05-22T14:56:28.000Z",
"id": "3",
"title": "JSON API paints my bikeshed!",
"created": "2015-05-22T14:56:29.000Z",
"type": "articles",
"body": "The shortest article. Ever."
}
],
"meta": {
"total-pages": 13
},
"links": {
"prev": "http://example.com/articles?page[number]=2&page[size]=1",
"first": "http://example.com/articles?page[number]=1&page[size]=1",
"next": "http://example.com/articles?page[number]=4&page[size]=1",
"self": "http://example.com/articles?page[number]=3&page[size]=1",
"last": "http://example.com/articles?page[number]=13&page[size]=1"
},
"additional": {
"info": "My custom info"
}
}
Parsing with include list
For defining which nested object you want to parse, you can use includeList parameter. For example:
{
"data": {
"type": "articles",
"id": "1",
"attributes": {
"title": "JSON API paints my bikeshed!",
"body": "The shortest article. Ever.",
"created": "2015-05-22T14:56:29.000Z",
"updated": "2015-05-22T14:56:28.000Z"
},
"relationships": {
"author": {
"data": {
"id": "42",
"type": "people"
}
}
}
},
"included": [
{
"type": "people",
"id": "42",
"attributes": {
"name": "John",
"age": 80,
"gender": "male"
},
"relationships": {
"article": {
"data": {
"id": "1",
"type": "articles"
}
}
}
}
]
}
Article and Author can be matched using include reference, as defined in JSON:API Specification:
let includeList: String = "author.article.author"
let jsonApiObject: [String: Any] = ...
let recursiveObject: [String: Any] = try Japx.Decoder.jsonObject(with: jsonApiObject, includeList: includeList)
Parsed JSON:
{
"data": {
"type": "articles",
"id": "1",
"title": "JSON API paints my bikeshed!",
"body": "The shortest article. Ever.",
"created": "2015-05-22T14:56:29.000Z",
"updated": "2015-05-22T14:56:28.000Z",
"author": {
"type": "people",
"id": "42",
"name": "John",
"age": 80,
"gender": "male",
"article": {
"type": "articles",
"id": "1",
"title": "JSON API paints my bikeshed!",
"body": "The shortest article. Ever.",
"created": "2015-05-22T14:56:29.000Z",
"updated": "2015-05-22T14:56:28.000Z",
"author": {
"type": "people",
"id": "42",
"name": "John",
"age": 80,
"gender": "male"
}
}
}
}
}
Usage
Codable
Japx comes with wrapper for Swift 4 Codable which can be installed as described in installation chapter.
Since JSON:API object can have multiple additional fields like meta, links or pagination info, its real model needs to be wrapped inside data object. For easier parsing, also depending on your API specification, you should create wrapping native object which will contain your generic JSON model:
struct JapxResponse<T: Codable>: Codable {
let data: T
// ... additional info like: meta, links, pagination...
}
struct User: JapxCodable {
let id: String
let type: String
let email: String
let username: String
}
let userResponse: JapxResponse<User> = try JapxDecoder()
.decode(JapxResponse<User>.self, from: data)
let user: User = userResponse.data
where JapxDecodable and JapxEncodable are defined in JapxCodable file as:
/// Protocol that extends Decodable with required properties for JSON:API objects
protocol JapxDecodable: Decodable {
var type: String { get }
var id: String { get }
}
/// Protocol that extends Encodable with required properties for JSON:API objects
protocol JapxEncodable: Encodable {
var type: String { get }
}
Codable and Alamofire
Japx also comes with wrapper for Alamofire and Codable which can be installed as described in installation chapter.
Use responseCodableJSONAPI method on DataRequest which will pass serialized response in callback. Also, there is keyPath argument to extract only nested data object. So, if you don't need any additional info from API side except plain data, than you can create simple objects, without using wrapping objects/structs.
struct User: JapxCodable {
let id: String
let type: String
let email: String
let username: String
}
Alamofire
.request(".../api/v1/users/login", method: .post, parameters: [...])
.validate()
.responseCodableJSONAPI(keyPath: "data", completionHandler: { (response: DataResponse<User>) in
switch response.result {
case .success(let user):
print(user)
case .failure(let error):
print(error)
}
})
Codable, Alamofire and RxSwift
Japx also comes with wrapper for Alamofire, Codable and RxSwift which can be installed as described in installation chapter.
Use responseCodableJSONAPI method from .rx extension on DataRequest which will return Single with serialized response.
let loginModel: LoginModel = ...
let executeLogin: ([String: Any]) throws -> Single<User> = {
return Alamofire
.request(".../api/v1/users/login", method: .post, parameters: $0)
.validate()
.rx.responseCodableJSONAPI(keyPath: "data")
}
return Single.just(loginModel)
.map { try JapxEncoder().encode($0) }
.flatMap(executeLogin)
Installation
Japx is available through CocoaPods. To install it, simply add the following line to your Podfile:
pod 'Japx'
We've added some more functionalites by conforming to Codable for object mapping or Alamofre for networking. You can find those convinience extansions here:
# Codable
pod 'Japx/Codable'
# Alamofire
pod 'Japx/Alamofire'
# Alamofire and RxSwift
pod 'Japx/RxAlamofire'
# Alamofire and Codable
pod 'Japx/CodableAlamofire'
# Alamofire, Codable and RxSwift
pod 'Japx/RxCodableAlamofire'
Example project
Example project of Japx networking using Codable and Alamofire can be found in Nuts And Bolts repository with commonly used code. Example will cover how to handle basic CRUD (Create, Read, Update, Delete) operations with Japx and JSON:API format. To run the example, clone the repository, open the Catalog.xcworkspace, run Catalog app and navigate to the Japx Networking section.
In this repository there is also simple example project, to run it clone the repository, and run pod install from the Example directory first.
Authors
- Vlaho Poluta, [email protected]
- Filip Gulan, [email protected]
Maintained by Infinum
License
Japx is available under the MIT license. See the LICENSE file for more info.