keep default model value for optimization

KakaJSON/Convert/Convertible.swift

@@ -264,7 +264,9 @@ extension Convertible {
  }
 
  // try to convert newValue to propertyType
- guard let value = Values.value(newValue, propertyType) else {
+ guard let value = Values.value(newValue,
+ propertyType,
+ property.get(from: model)) else {
  property.set(newValue, for: model)
  continue
  }

KakaJSON/Convert/Values.swift

@@ -12,15 +12,17 @@ import CoreGraphics
 #endif
 
 public struct Values {
- static func value(_ val: Any?, _ type: Any.Type) -> Any? {
+ static func value(_ val: Any?,
+ _ type: Any.Type,
+ _ defaultValue: @autoclosure () -> Any? = nil) -> Any? {
  guard let v = val.kj_value else { return nil }
  if Swift.type(of: v) == type { return v }
  if v is NSNull { return nil }
 
  switch type {
  case is NumberValue.Type: return _number(v, type)
  case is StringValue.Type: return _string(v, type)
- case let ct as Convertible.Type: return _model(v, ct)
+ case let ct as Convertible.Type: return _model(v, ct, defaultValue)
  case is DateValue.Type: return _date(v)
  case is ArrayValue.Type: return _array(v, type)
  case is DictionaryValue.Type: return _dictionary(v, type)
@@ -73,8 +75,14 @@ private extension Values {
  return lower
  }
 
- static func _model(_ value: Any, _ type: Convertible.Type) -> Convertible? {
+ static func _model(_ value: Any,
+ _ type: Convertible.Type,
+ _ defaultValue: () -> Any?) -> Convertible? {
  guard let json = value as? [String: Any] else { return nil }
+ if var model = defaultValue().kj_value as? Convertible {
+ model.kj_convert(from: json)
+ return model
+ }
  return json.kj.model(type: type)
  }
 

KakaJSONTests/JSON_To_Model/JTM_03_NestedModel.swift

@@ -72,6 +72,48 @@ class JTM_03_NestedModel: XCTestCase {
  XCTAssert(person.dogs?["dog1"]?.name == dogs[1].name)
  XCTAssert(person.dogs?["dog1"]?.age == dogs[1].age)
  }
+
+ func testDefaultValue() {
+ struct Car: Convertible {
+ var name: String = ""
+ var price: Double = 0.0
+ }
+
+ class Dog: Convertible {
+ var name: String = ""
+ var age: Int = 0
+ required init() {}
+ init(name: String, age: Int) {
+ self.name = name
+ self.age = age
+ }
+ }
+
+ struct Person: Convertible {
+ var name: String = ""
+ // KakaJSON will use your defaultValue instead of creating a new model
+ // KakaJSON will not creat a new model again if you already have a default model value
+ var car: Car = Car(name: "Bently", price: 106.5)
+ var dog: Dog = Dog(name: "Larry", age: 5)
+ }
+
+ let json: [String: Any] = [
+ "name": "Jake",
+ "car": ["price": 305.6],
+ "dog": ["name": "Wangwang"]
+ ]
+
+ let person = json.kj.model(Person.self)
+ XCTAssert(person.name == "Jake")
+ // keep defaultValue
+ XCTAssert(person.car.name == "Bently")
+ // use value from json
+ XCTAssert(person.car.price == 305.6)
+ // use value from json
+ XCTAssert(person.dog.name == "Wangwang")
+ // keep defaultValue
+ XCTAssert(person.dog.age == 5)
+ }
 
  func testRecursive() {
  class Person: Convertible {

README.md

@@ -50,6 +50,7 @@ Or you can login Xcode with your GitHub account. just search **KakaJSON**.
  - [JSONData](#jsondata)
  - [Nested Model 1](#nested-model-1)
  - [Nested Model 2](#nested-model-2)
+ - [Nested Model 3](#nested-model-3)
  - [Recursive](#recursive)
  - [Generic](#generic)
  - [Model Array](#model-array)
@@ -487,6 +488,49 @@ XCTAssert(book?.name == "Fast C++")
 XCTAssert(book?.price == 666.6)
 ```
 
+### Nested Model3
+```swift
+struct Car: Convertible {
+ var name: String = ""
+ var price: Double = 0.0
+}
+
+class Dog: Convertible {
+ var name: String = ""
+ var age: Int = 0
+ required init() {}
+ init(name: String, age: Int) {
+ self.name = name
+ self.age = age
+ }
+}
+
+struct Person: Convertible {
+ var name: String = ""
+ // KakaJSON will use your defaultValue instead of creating a new model
+ // KakaJSON will not creat a new model again if you already have a default model value
+ var car: Car = Car(name: "Bently", price: 106.5)
+ var dog: Dog = Dog(name: "Larry", age: 5)
+}
+
+let json: [String: Any] = [
+ "name": "Jake",
+ "car": ["price": 305.6],
+ "dog": ["name": "Wangwang"]
+]
+
+let person = json.kj.model(Person.self)
+XCTAssert(person.name == "Jake")
+// keep defaultValue
+XCTAssert(person.car.name == "Bently")
+// use value from json
+XCTAssert(person.car.price == 305.6)
+// use value from json
+XCTAssert(person.dog.name == "Wangwang")
+// keep defaultValue
+XCTAssert(person.dog.age == 5)
+```
+
 ### Recursive
 ```swift
 class Person: Convertible {