BaseJson4

Swift4 JSON to Object or Object to JSON

Project maintained by kittymo Hosted on GitHub Pages — Theme by mattgraham

BaseJson4

CocoaPods

BaseJson4 makes you more easier to transform data type from JSON to Object or reverse.</br> *support only Swift 4 and above

Why use BaseJson4 in your project?
Features
Integration
- CocoaPods
- Manually
Requirements
Usage

Why use BaseJson4 in your project?

We want to handle data which is JSON string getting from backend with service API, we have to useDictionaryorArrayto transform or parse data in to the model, until Swift 4 Codable introduced.

The BaseJson4 base on new protocolCodablecould let you more easier to useCodablefeature and more clean your own code and more importantly reduce low-level errors by hands with autocomplete.

Handle the object property rather than handle a string [“user”] make Xcode to check is it correct.

With BaseJson4 just use User Object, User could be Class or Struct all you have to do this:

  if let user = jsonStr.toObj(type: User.self) {
    print("userName= \(user.name)")
    let age = user.age
  }

With official Apple Example would look like this:

if let statusesArray = try? JSONSerialization.jsonObject(with: data, options: .allowFragments) as? [[String: Any]],
    let user = statusesArray[0]["user"] as? [String: Any],
    let userName = user["name"] as? String {
    print("userName= \(user.name)")
}

With SwiftyJSON would look like this:

let json = JSON(data: dataFromNetworking)
if let userName = json[0]["user"]["name"].string {
    print("userName= \(user.name)")
}

see, BaseJson4 more clean right?

Features

JSON String –> Object Model
Object Model –> JSON String
Different name mapping
Specific Date format transformer
Print the contents of an object

Requirements

iOS 9.0+ macOS 10.10+
Xcode 9
Swift 4.0

Integration

CocoaPods (iOS 9+, OS X 10.10+)

You can use CocoaPods to installBaseJson4by adding it to yourPodfile:

platform :ios, '9.0'
use_frameworks!

target 'MyApp' do
	pod 'BaseJson4'
end

Manually

To use this library in your project manually you may:

Download BaseJson4.swift file form github
add the BaseJson4.swift file in your project
no more step 2

Usage

1. Json to Object

Here is a Json string

{"id":66, "birthday":"1997-05-08", "height": 180.61, "name":"kittymo", "gender":"M", "age": 29, "friends": [ {"name":"Bill", "isFriend": true}, {"name":"Allen", "isFriend": false, "test":1} ]}

First of all create the object Model, in here we using class, of course you can using struct if you want.

class User: BaseJson4 {
    var name: String? = nil
    var gender: String? = nil
    var age: Int = 0
    var birthday: String? = nil
    var friends: [Friend]? = nil
    var height: Double = 0    
}

class Friend: BaseJson4 {
    var name: String? = nil
    var isFriend: Bool = false
}

The String/Datahas beenextensionby BaseJson4 with methodtoObj

Source of Json data types could beStringorDatayou can use like this code follow:

let jsonStr = "{"id":66, "birthday":"1997-05-08", "height": 180.61, "name":"kittymo", "gender":"M", "age": 29, "friends": [ {"name":"Bill", "isFriend": true}, {"name":"Allen", "isFriend": false, "test":1} ]}"

if let user = jsonStr.toObj(type: User.self) {
    let desc = user.description()   // description() method can print all of properties in this object 
    print("Object content ==> \(desc)")

    // .... just use this obeject

    let age = user.age
    let name = user.name
    if let friends = user.friends {
        for friend in friends {
          print("friend name=\(friend.name)")
        }
    }
}

Just one line code, String.toObj, we succeed transform from a Json string to an object Model
here is output log on console follow:

Object content ==> 
<User:
 name=Optional("kittymo")
 gender=Optional("M")
 age=29
 birthday=Optional("1997-05-08")
 friends=Array count=2 [ <Friend: name=Optional("Bill") isFriend=true>, <Friend: name=Optional("Allen") isFriend=false> ]
 height=180.61
>

friend name=Optional("Bill")
friend name=Optional("Allen")

Is it easy, right?

Remember Json string has a property named birthday, it’s a birthday date, we want to it’s data typs can transform from String to Data Object.

Here is show you how to do that follow:

Just change two place (where comment) follow:

class User: BaseJson4 {
    var name: String? = nil
    var gender: String? = nil
    var age: Int = 0
    var birthday: Date? = nil       // <--- change type annotation here from String to Data
    var friends: [Friend]? = nil
    var height: Double = 0    
    
    static func dateFormats() -> [String: String]? {
        return [CodingKeys.birthday.stringValue: "yyyy-MM-dd"]  // <--- define date format you want like: yyyy-MM-dd
    }
}

That’s it, property birthday is became Date date type! yeh!
after modify the output log on console follow

Object content ==>  
<User:
 name=Optional("kittymo")
 gender=Optional("M")
 age=29
 birthday=Optional(1997-05-07 16:00:00 +0000)
 friends=Array count=2 [ <Friend: name=Optional("Bill") isFriend=true>, <Friend: name=Optional("Allen") isFriend=false> ]
 height=180.61
>

2. Object to Json

How do we do transform from an Object to Json string?.

Well, it’s very simple, just one line code.

let jsonStr = user.toJson()
print("json string = \(jsonStr)")

the output log on console follow:

json string = {"age":29,"gender":"M","friends":[{"name":"Bill","isFriend":true},{"name":"Allen","isFriend":false}],"name":"kittymo","birthday":"1997-05-08","height":180.61000000000001}

It is suitable way if for machine read with default format If you want to print out Json format for human read, add the argument like user.toJson(.prettyPrinted)

let jsonStr = user.toJson(.prettyPrinted)  // <--- modify by argument: prettyPrinted 

the output will be nice to human read, log on console follow:

json string = {
  "age" : 29,
  "gender" : "M",
  "friends" : [
    {
      "name" : "Bill",
      "isFriend" : true
    },
    {
      "name" : "Allen",
      "isFriend" : false
    }
  ],
  "name" : "kittymo",
  "birthday" : "1997-05-08",
  "height" : 180.61000000000001
}

3. Different name mapping

When we get Json string which is not Swift style, we want to modify that to be Swift style, you can using different name mapping here is show you how to do different name mapping way.

 {"user_id":66, "user_name":"阿媛", "valid":true, "sex":"F", "style":"村菇"}

We want let the columnuser_nameto be name, user_id to be userId

ModifyUserobject model, and add CodingKeys like follow:

class User: BaseJson4 {
    var userId: Int = 0
    var name: String? = nil
    var gender: String? = nil
    var valid: Bool = false
    var style: String? = nil
    
    //  Reset CodingKeys to do different name mapping
    
    enum CodingKeys : String, CodingKey {
        case userId = "user_id"     // different name mapping
        case name = "user_name"     // different name mapping
        case gender = "sex"         // different name mapping
        case valid	// same name
        case style	// same name 
    }
}

Notice: if you have reset CodingKeys to do different name mapping, all of properties must be set with same name, Do not be ignored if the column name is the same name.

The method Json -> Object just the same before: ```swift let jsonStr = "{\"user_id\":66, \"user_name\":\"阿媛\", \"valid\":true, \"sex\":\"F\", \"style\":\"村菇\"}" print("input json string ==> \(jsonStr)") // json string --> Object if let user = jsonStr.toObj(type: User.self) { let desc = user.description() print("Object content ==> \(desc)") // Object --> json string let ss = user.toJson(.prettyPrinted) print("json string = \(ss)") } ``` the output log on console follow: ```text input json string ==> {"user_id":66, "user_name":"阿媛", "valid":true, "sex":"F", "style":"村菇"} Object content ==> <User: userId=66 name=Optional("阿媛") gender=Optional("F") valid=true style=Optional("村菇") > json string = { "sex" : "F", "style" : "村菇", "user_id" : 66, "valid" : true, "user_name" : "阿媛" } ``` Just rename the column name, it's perfect mapping in to the object model. Translated by TerryCK