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https://github.com/alibaba/handyjson

A handy swift json-object serialization/deserialization library
https://github.com/alibaba/handyjson

deserialization json json-fields mapping serialization swift

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A handy swift json-object serialization/deserialization library

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README 

        
# HandyJSON



***To deal with crash on iOS 15 beta3 please try version 5.0.4-beta***



HandyJSON is a framework written in Swift which to make converting model objects( **pure classes/structs** ) to and from JSON easy on iOS.



Compared with others, the most significant feature of HandyJSON is that it does not require the objects inherit from NSObject(**not using KVC but reflection**), neither implements a 'mapping' function(**writing value to memory directly to achieve property assignment**).



HandyJSON is totally depend on the memory layout rules infered from Swift runtime code. We are watching it and will follow every bit if it changes.



[![Build Status](https://travis-ci.org/alibaba/HandyJSON.svg?branch=master)](https://travis-ci.org/alibaba/HandyJSON)

[![Carthage compatible](https://img.shields.io/badge/Carthage-compatible-4BC51D.svg?style=flat)](https://github.com/Carthage/Carthage)

[![Cocoapods Version](https://img.shields.io/cocoapods/v/HandyJSON.svg?style=flat)](http://cocoadocs.org/docsets/HandyJSON)

[![Cocoapods Platform](https://img.shields.io/cocoapods/p/HandyJSON.svg?style=flat)](http://cocoadocs.org/docsets/HandyJSON)

[![Codecov branch](https://img.shields.io/codecov/c/github/alibaba/HandyJSON/master.svg?style=flat)](https://codecov.io/gh/alibaba/HandyJSON/branch/master)



## [中文文档](./README_cn.md)



## 交流群



群号: 581331250



![交流群](qq_group.png)



## Sample Code



### Deserialization



```swift

class BasicTypes: HandyJSON {

    var int: Int = 2

    var doubleOptional: Double?

    var stringImplicitlyUnwrapped: String!



    required init() {}

}



let jsonString = "{\"doubleOptional\":1.1,\"stringImplicitlyUnwrapped\":\"hello\",\"int\":1}"

if let object = BasicTypes.deserialize(from: jsonString) {

    print(object.int)

    print(object.doubleOptional!)

    print(object.stringImplicitlyUnwrapped)

}

```



### Serialization



```swift



let object = BasicTypes()

object.int = 1

object.doubleOptional = 1.1

object.stringImplicitlyUnwrapped = “hello"



print(object.toJSON()!) // serialize to dictionary

print(object.toJSONString()!) // serialize to JSON string

print(object.toJSONString(prettyPrint: true)!) // serialize to pretty JSON string

```



# Content



- [Features](#features)

- [Requirements](#requirements)

- [Installation](#installation)

    - [Cocoapods](#cocoapods)

    - [Carthage](#carthage)

    - [Manually](#manually)

- [Deserialization](#deserialization)

    - [The Basics](#the-basics)

    - [Support Struct](#support-struct)

    - [Support Enum Property](#support-enum-property)

    - [Optional/ImplicitlyUnwrappedOptional/Collections/...](#optionalimplicitlyunwrappedoptionalcollections)

    - [Designated Path](#designated-path)

    - [Composition Object](#composition-object)

    - [Inheritance Object](#inheritance-object)

    - [JSON Array](#json-array)

    - [Mapping From Dictionary](#mapping-from-dictionary)

    - [Custom Mapping](#custom-mapping)

    - [Date/Data/URL/Decimal/Color](#datedataurldecimalcolor)

    - [Exclude Property](#exclude-property)

    - [Update Existing Model](#update-existing-model)

    - [Supported Property Type](#supported-property-type)

- [Serialization](#serialization)

    - [The Basics](#the-basics)

    - [Mapping And Excluding](#mapping-and-excluding)

- [FAQ](#faq)

- [To Do](#to-do)



# Features



* Serialize/Deserialize Object/JSON to/From JSON/Object



* Naturally use object property name for mapping, no need to specify a mapping relationship



* Support almost all types in Swift, including enum



* Support struct



* Custom transformations



* Type-Adaption, such as string json field maps to int property, int json field maps to string property



An overview of types supported can be found at file: [BasicTypes.swift](./HandyJSONTest/BasicTypes.swift)



# Requirements



* iOS 8.0+/OSX 10.9+/watchOS 2.0+/tvOS 9.0+



* Swift 3.0+ / Swift 4.0+ / Swift 5.0+



# Installation



**To use with Swift 5.0/5.1 ( Xcode 10.2+/11.0+ ), version == 5.0.2**



**To use with Swift 4.2 ( Xcode 10 ), version == 4.2.0**



**To use with Swift 4.0, version >= 4.1.1**



**To use with Swift 3.x, version >= 1.8.0**



For Legacy Swift2.x support, take a look at the [swift2 branch](https://github.com/alibaba/HandyJSON/tree/master_for_swift_2x).



## Cocoapods



Add the following line to your `Podfile`:



```

pod 'HandyJSON', '~> 5.0.2'

```



Then, run the following command:



```

$ pod install

```



## Carthage



You can add a dependency on `HandyJSON` by adding the following line to your `Cartfile`:



```

github "alibaba/HandyJSON" ~> 5.0.2

```



## Manually



You can integrate `HandyJSON` into your project manually by doing the following steps:



* Open up `Terminal`, `cd` into your top-level project directory, and add `HandyJSON` as a submodule:



```

git init && git submodule add https://github.com/alibaba/HandyJSON.git

```



* Open the new `HandyJSON` folder, drag the `HandyJSON.xcodeproj` into the `Project Navigator` of your project.



* Select your application project in the `Project Navigator`, open the `General` panel in the right window.



* Click on the `+` button under the `Embedded Binaries` section.



* You will see two different `HandyJSON.xcodeproj` folders each with four different versions of the HandyJSON.framework nested inside a Products folder.

> It does not matter which Products folder you choose from, but it does matter which HandyJSON.framework you choose.



* Select one of the four `HandyJSON.framework` which matches the platform your Application should run on.



* Congratulations!



# Deserialization



## The Basics



To support deserialization from JSON, a class/struct need to conform to 'HandyJSON' protocol. It's truly protocol, not some class inherited from NSObject.



To conform to 'HandyJSON', a class need to implement an empty initializer.



```swift

class BasicTypes: HandyJSON {

    var int: Int = 2

    var doubleOptional: Double?

    var stringImplicitlyUnwrapped: String!



    required init() {}

}



let jsonString = "{\"doubleOptional\":1.1,\"stringImplicitlyUnwrapped\":\"hello\",\"int\":1}"

if let object = BasicTypes.deserialize(from: jsonString) {

    // …

}

```



## Support Struct



For struct, since the compiler provide a default empty initializer, we use it for free.



```swift

struct BasicTypes: HandyJSON {

    var int: Int = 2

    var doubleOptional: Double?

    var stringImplicitlyUnwrapped: String!

}



let jsonString = "{\"doubleOptional\":1.1,\"stringImplicitlyUnwrapped\":\"hello\",\"int\":1}"

if let object = BasicTypes.deserialize(from: jsonString) {

    // …

}

```



But also notice that, if you have a designated initializer to override the default one in the struct, you should explicitly declare an empty one(no `required` modifier need).



## Support Enum Property



To be convertable, An `enum` must conform to `HandyJSONEnum` protocol. Nothing special need to do now.



```swift

enum AnimalType: String, HandyJSONEnum {

    case Cat = "cat"

    case Dog = "dog"

    case Bird = "bird"

}



struct Animal: HandyJSON {

    var name: String?

    var type: AnimalType?

}



let jsonString = "{\"type\":\"cat\",\"name\":\"Tom\"}"

if let animal = Animal.deserialize(from: jsonString) {

    print(animal.type?.rawValue)

}

```



## Optional/ImplicitlyUnwrappedOptional/Collections/...



'HandyJSON' support classes/structs composed of `optional`, `implicitlyUnwrappedOptional`, `array`, `dictionary`, `objective-c base type`, `nested type` etc. properties.



```swift

class BasicTypes: HandyJSON {

    var bool: Bool = true

    var intOptional: Int?

    var doubleImplicitlyUnwrapped: Double!

    var anyObjectOptional: Any?



    var arrayInt: Array = []

    var arrayStringOptional: Array?

    var setInt: Set?

    var dictAnyObject: Dictionary = [:]



    var nsNumber = 2

    var nsString: NSString?



    required init() {}

}



let object = BasicTypes()

object.intOptional = 1

object.doubleImplicitlyUnwrapped = 1.1

object.anyObjectOptional = "StringValue"

object.arrayInt = [1, 2]

object.arrayStringOptional = ["a", "b"]

object.setInt = [1, 2]

object.dictAnyObject = ["key1": 1, "key2": "stringValue"]

object.nsNumber = 2

object.nsString = "nsStringValue"



let jsonString = object.toJSONString()!



if let object = BasicTypes.deserialize(from: jsonString) {

    // ...

}

```



## Designated Path



`HandyJSON` supports deserialization from designated path of JSON.



```swift

class Cat: HandyJSON {

    var id: Int64!

    var name: String!



    required init() {}

}



let jsonString = "{\"code\":200,\"msg\":\"success\",\"data\":{\"cat\":{\"id\":12345,\"name\":\"Kitty\"}}}"



if let cat = Cat.deserialize(from: jsonString, designatedPath: "data.cat") {

    print(cat.name)

}

```



## Composition Object



Notice that all the properties of a class/struct need to deserialized should be type conformed to `HandyJSON`.



```swift

class Component: HandyJSON {

    var aInt: Int?

    var aString: String?



    required init() {}

}



class Composition: HandyJSON {

    var aInt: Int?

    var comp1: Component?

    var comp2: Component?



    required init() {}

}



let jsonString = "{\"num\":12345,\"comp1\":{\"aInt\":1,\"aString\":\"aaaaa\"},\"comp2\":{\"aInt\":2,\"aString\":\"bbbbb\"}}"



if let composition = Composition.deserialize(from: jsonString) {

    print(composition)

}

```



## Inheritance Object



A subclass need deserialization, it's superclass need to conform to `HandyJSON`.



```swift

class Animal: HandyJSON {

    var id: Int?

    var color: String?



    required init() {}

}



class Cat: Animal {

    var name: String?



    required init() {}

}



let jsonString = "{\"id\":12345,\"color\":\"black\",\"name\":\"cat\"}"



if let cat = Cat.deserialize(from: jsonString) {

    print(cat)

}

```



## JSON Array



If the first level of a JSON text is an array, we turn it to objects array.



```swift

class Cat: HandyJSON {

    var name: String?

    var id: String?



    required init() {}

}



let jsonArrayString: String? = "[{\"name\":\"Bob\",\"id\":\"1\"}, {\"name\":\"Lily\",\"id\":\"2\"}, {\"name\":\"Lucy\",\"id\":\"3\"}]"

if let cats = [Cat].deserialize(from: jsonArrayString) {

    cats.forEach({ (cat) in

        // ...

    })

}

```



## Mapping From Dictionary



`HandyJSON` support mapping swift dictionary to model.



```swift

var dict = [String: Any]()

dict["doubleOptional"] = 1.1

dict["stringImplicitlyUnwrapped"] = "hello"

dict["int"] = 1

if let object = BasicTypes.deserialize(from: dict) {

    // ...

}

```



## Custom Mapping



`HandyJSON` let you customize the key mapping to JSON fields, or parsing method of any property. All you need to do is implementing an optional `mapping` function, do things in it.



We bring the transformer from [`ObjectMapper`](https://github.com/Hearst-DD/ObjectMapper). If you are familiar with it, it’s almost the same here.



```swift

class Cat: HandyJSON {

    var id: Int64!

    var name: String!

    var parent: (String, String)?

    var friendName: String?



    required init() {}



    func mapping(mapper: HelpingMapper) {

        // specify 'cat_id' field in json map to 'id' property in object

        mapper <<<

            self.id <-- "cat_id"



        // specify 'parent' field in json parse as following to 'parent' property in object

        mapper <<<

            self.parent <-- TransformOf<(String, String), String>(fromJSON: { (rawString) -> (String, String)? in

                if let parentNames = rawString?.characters.split(separator: "/").map(String.init) {

                    return (parentNames[0], parentNames[1])

                }

                return nil

            }, toJSON: { (tuple) -> String? in

                if let _tuple = tuple {

                    return "\(_tuple.0)/\(_tuple.1)"

                }

                return nil

            })



        // specify 'friend.name' path field in json map to 'friendName' property

        mapper <<<

            self.friendName <-- "friend.name"

    }

}



let jsonString = "{\"cat_id\":12345,\"name\":\"Kitty\",\"parent\":\"Tom/Lily\",\"friend\":{\"id\":54321,\"name\":\"Lily\"}}"



if let cat = Cat.deserialize(from: jsonString) {

    print(cat.id)

    print(cat.parent)

    print(cat.friendName)

}

```



## Date/Data/URL/Decimal/Color



`HandyJSON` prepare some useful transformer for some none-basic type.



```swift

class ExtendType: HandyJSON {

    var date: Date?

    var decimal: NSDecimalNumber?

    var url: URL?

    var data: Data?

    var color: UIColor?



    func mapping(mapper: HelpingMapper) {

        mapper <<<

            date <-- CustomDateFormatTransform(formatString: "yyyy-MM-dd")



        mapper <<<

            decimal <-- NSDecimalNumberTransform()



        mapper <<<

            url <-- URLTransform(shouldEncodeURLString: false)



        mapper <<<

            data <-- DataTransform()



        mapper <<<

            color <-- HexColorTransform()

    }



    public required init() {}

}



let object = ExtendType()

object.date = Date()

object.decimal = NSDecimalNumber(string: "1.23423414371298437124391243")

object.url = URL(string: "https://www.aliyun.com")

object.data = Data(base64Encoded: "aGVsbG8sIHdvcmxkIQ==")

object.color = UIColor.blue



print(object.toJSONString()!)

// it prints:

// {"date":"2017-09-11","decimal":"1.23423414371298437124391243","url":"https:\/\/www.aliyun.com","data":"aGVsbG8sIHdvcmxkIQ==","color":"0000FF"}



let mappedObject = ExtendType.deserialize(from: object.toJSONString()!)!

print(mappedObject.date)

...

```



## Exclude Property



If any non-basic property of a class/struct could not conform to `HandyJSON`/`HandyJSONEnum` or you just do not want to do the deserialization with it, you should exclude it in the mapping function.



```swift

class NotHandyJSONType {

    var dummy: String?

}



class Cat: HandyJSON {

    var id: Int64!

    var name: String!

    var notHandyJSONTypeProperty: NotHandyJSONType?

    var basicTypeButNotWantedProperty: String?



    required init() {}



    func mapping(mapper: HelpingMapper) {

        mapper >>> self.notHandyJSONTypeProperty

        mapper >>> self.basicTypeButNotWantedProperty

    }

}



let jsonString = "{\"name\":\"cat\",\"id\":\"12345\"}"



if let cat = Cat.deserialize(from: jsonString) {

    print(cat)

}

```



## Update Existing Model



`HandyJSON` support updating an existing model with given json string or dictionary.



```swift

class BasicTypes: HandyJSON {

    var int: Int = 2

    var doubleOptional: Double?

    var stringImplicitlyUnwrapped: String!



    required init() {}

}



var object = BasicTypes()

object.int = 1

object.doubleOptional = 1.1



let jsonString = "{\"doubleOptional\":2.2}"

JSONDeserializer.update(object: &object, from: jsonString)

print(object.int)

print(object.doubleOptional)

```



## Supported Property Type



* `Int`/`Bool`/`Double`/`Float`/`String`/`NSNumber`/`NSString`



* `RawRepresentable` enum



* `NSArray/NSDictionary`



* `Int8/Int16/Int32/Int64`/`UInt8/UInt16/UInt23/UInt64`



* `Optional/ImplicitUnwrappedOptional` // T is one of the above types



* `Array` // T is one of the above types



* `Dictionary` // T is one of the above types



* Nested of aboves



# Serialization



## The Basics



Now, a class/model which need to serialize to JSON should also conform to `HandyJSON` protocol.



```swift

class BasicTypes: HandyJSON {

    var int: Int = 2

    var doubleOptional: Double?

    var stringImplicitlyUnwrapped: String!



    required init() {}

}



let object = BasicTypes()

object.int = 1

object.doubleOptional = 1.1

object.stringImplicitlyUnwrapped = “hello"



print(object.toJSON()!) // serialize to dictionary

print(object.toJSONString()!) // serialize to JSON string

print(object.toJSONString(prettyPrint: true)!) // serialize to pretty JSON string

```



## Mapping And Excluding



It’s all like what we do on deserialization. A property which is excluded, it will not take part in neither deserialization nor serialization. And the mapper items define both the deserializing rules and serializing rules. Refer to the usage above.



# FAQ



## Q: Why the mapping function is not working in the inheritance object?



A: For some reason, you should define an empty mapping function in the super class(the root class if more than one layer), and override it in the subclass.



It's the same with `didFinishMapping` function.



## Q: Why my didSet/willSet is not working?



A: Since `HandyJSON` assign properties by writing value to memory directly, it doesn't trigger any observing function. You need to call the `didSet/willSet` logic explicitly after/before the deserialization.



But since version `1.8.0`, `HandyJSON` handle dynamic properties by the `KVC` mechanism which will trigger the `KVO`. That means, if you do really need the `didSet/willSet`, you can define your model like follow:



```swift

class BasicTypes: NSObject, HandyJSON {

    dynamic var int: Int = 0 {

        didSet {

            print("oldValue: ", oldValue)

        }

        willSet {

            print("newValue: ", newValue)

        }

    }



    public override required init() {}

}

```



In this situation, `NSObject` and `dynamic` are both needed.



And in versions since `1.8.0`, `HandyJSON` offer a `didFinishMapping` function to allow you to fill some observing logic.



```swift

class BasicTypes: HandyJSON {

    var int: Int?



    required init() {}



    func didFinishMapping() {

        print("you can fill some observing logic here")

    }

}



```



It may help.



## Q: How to support Enum property?



It your enum conform to `RawRepresentable` protocol, please look into [Support Enum Property](#support-enum-property). Or use the `EnumTransform`:



```swift

enum EnumType: String {

    case type1, type2

}



class BasicTypes: HandyJSON {

    var type: EnumType?



    func mapping(mapper: HelpingMapper) {

        mapper <<<

            type <-- EnumTransform()

    }



    required init() {}

}



let object = BasicTypes()

object.type = EnumType.type2

print(object.toJSONString()!)

let mappedObject = BasicTypes.deserialize(from: object.toJSONString()!)!

print(mappedObject.type)

```



Otherwise, you should implement your custom mapping function.



```swift

enum EnumType {

    case type1, type2

}



class BasicTypes: HandyJSON {

    var type: EnumType?



    func mapping(mapper: HelpingMapper) {

        mapper <<<

            type <-- TransformOf(fromJSON: { (rawString) -> EnumType? in

                if let _str = rawString {

                    switch (_str) {

                    case "type1":

                        return EnumType.type1

                    case "type2":

                        return EnumType.type2

                    default:

                        return nil

                    }

                }

                return nil

            }, toJSON: { (enumType) -> String? in

                if let _type = enumType {

                    switch (_type) {

                    case EnumType.type1:

                        return "type1"

                    case EnumType.type2:

                        return "type2"

                    }

                }

                return nil

            })

    }



    required init() {}

}

```



# Credit



* [reflection](https://github.com/Zewo/Reflection): After the first version which used the swift mirror mechanism, HandyJSON had imported the reflection library and rewrote some code for class properties inspecting.

* [ObjectMapper](https://github.com/tristanhimmelman/ObjectMapper): To make HandyJSON more compatible with the general style, the Mapper function support Transform which designed by ObjectMapper. And we import some testcases from ObjectMapper.



# License



HandyJSON is released under the Apache License, Version 2.0. See LICENSE for details.