[swift] 41. 디자인 패턴-빌더 패턴

디자인 패턴 종류

• 객체 관련
• 빌더 관련
• 행위 관련

빌더 패턴

• 클래스에서 생성할 객체를 멤버변수로 가짐
• 함수로 자기 자신을 내뱉음
• 마지막에 build()

첫번째 방식

struct Pet {
	var name: String? = nil
	var age: Int? = nil
}

class PetBuilder{
	private var pet : Pet = Pet()
    //Self == PetBuilder
    func withName(_ name: String) -> Self {
    	pet.name = name
        return self
    }
    
    func withAge(_ age: Int) -> Self {
    	pet.age = age
        return self
    }
    func build() -> Pet {
    	return self.pet
    }
}

let myPet = PetBuilder()
			.withName("a")
            .withAge(10)
            .build()

두번째 방식 (closure)

struct Pet {
	var name: String? = nil
	var age: Int? = nil
    
    init(){}
    init(builder: SecondPetBuilder){
    	self.name = builder.name
        self.age = builder.age
    }
}

class SecondPetBuilder{
	var name: String? = nil
    var age: Int? = nil
    
    typealias BuilderClosure = (SecondPetBuilder) -> ()
    
    init(buildClosure: BuilderClosure){
    	buildClosure(self)
    }
}

let petBuilder = SecondPetBuilder { builder in
	builder.name = "댕댕이"
    builder.age = 10
}

let mySecondPet = Pet(builder: petBuilder)