iOS设计模式 (九)构建者模式

概念

建造者模式是设计模式的一种，将一个复杂对象的构建与它的表示分离，使得同样的构建过程可以创建不同的表示。

UML 9.png

构建者模式由三部分构成

• 指挥者 (Director）
• 构建者 (Builder）
• 生成者 (ConcreteBuilder)

项目需求

客户想要店主冲一杯带糖，加珍珠，加牛奶，加椰果的奶茶

• 指挥者：店主
• 构建者：奶茶
• 生成者:糖,珍珠，牛奶，椰果

demo实例

• TeaBuilder (协议)

#import <Foundation/Foundation.h>
#import "MilkGenerateProtocol.h"

@protocol TeaBuilder <NSObject>


/**
  构建糖
 */
- (id <TeaBuilder>)buildSugar:(NSString *)sugar;
/**
 构建牛奶
 */
- (id <TeaBuilder>)buildMilk:(NSString *)milk;
/**
 构建珍珠
 */
- (id <TeaBuilder>)buildPearl:(NSString *)milk;
/**
 构建椰果
 */
- (id <TeaBuilder>)buildNatadecoco:(NSString *)milk;

/**
 构建喝
 */
- (id<MilkGenerateProtocol>)drink;

@end

• Director 类

#import <Foundation/Foundation.h>
#import "TeaBuilder.h"

@interface Director : NSObject

- (instancetype)initWithDirector:(id <TeaBuilder>)builder;

- (void)contractWithDirector:(NSString *)suger
                        milk:(NSString *)milk
                        peal:(NSString *)peal
                  natadecoco:(NSString *)natadecoco;
@end

#import "Director.h"


@interface Director ()

@property (nonatomic, strong) id <TeaBuilder> Tmilk;

@end

@implementation Director

- (instancetype)initWithDirector:(id <TeaBuilder>)builder
{
    self = [super init];
    if (self) {
        self.Tmilk = builder;
    }
    return self;
}

- (void)contractWithDirector:(NSString *)suger milk:(NSString *)milk peal:(NSString *)peal natadecoco:(NSString *)natadecoco
{
    [[[[[self.Tmilk buildSugar:suger] buildMilk:milk] buildPearl:peal] buildNatadecoco:natadecoco] drink];
}

@end

• MilkGenerateProtocol (协议)

#import <Foundation/Foundation.h>



@protocol MilkGenerateProtocol <NSObject>

- (void)addSuger:(NSString *)suger;
- (void)addMilk:(NSString *)milk;
- (void)addPeal:(NSString *)peal;
- (void)addNatadecoco:(NSString *)natadecoco;
- (void)addDrink;

@end

• BuildMilkyTea

#import <Foundation/Foundation.h>
#import "TeaBuilder.h"

@interface BuildMilkyTea : NSObject <TeaBuilder>

@end
#import "BuildMilkyTea.h"
#import "MilkGenerateBuilder.h"

@interface BuildMilkyTea ()

@property (nonatomic, strong)id <MilkGenerateProtocol> milk;
@end

@implementation BuildMilkyTea


- (instancetype)init
{
    self = [super init];
    if (self) {
        self.milk = [[MilkGenerateBuilder alloc] init];
    }
    return self;
}
/**
 构建糖
 */
- (id <TeaBuilder>)buildSugar:(NSString *)sugar
{
    [_milk addSuger:sugar];
    return self;
}
/**
 构建牛奶
 */
- (id <TeaBuilder>)buildMilk:(NSString *)milk
{
    [_milk addMilk:milk];
    return self;
    
}
/**
 构建珍珠
 */
- (id <TeaBuilder>)buildPearl:(NSString *)milk
{
    [_milk addPeal:milk];
    return self;
    
}
/**
 构建糖
 */
- (id <TeaBuilder>)buildNatadecoco:(NSString *)milk
{
    [_milk addNatadecoco:milk];
    return self;
}

/**
 构建喝
 */
- (id<MilkGenerateProtocol>)drink
{
    [_milk addDrink];
    return _milk;
}
@end

• MilkGenerateBuilder

#import <Foundation/Foundation.h>
#import "MilkGenerateProtocol.h"

@interface MilkGenerateBuilder : NSObject <MilkGenerateProtocol>
@end

#import "MilkGenerateBuilder.h"

@implementation MilkGenerateBuilder


- (void)addSuger:(NSString *)suger
{
    NSLog(@"奶茶添加了：%@",suger);
}
- (void)addMilk:(NSString *)milk
{
    NSLog(@"奶茶添加了：%@",milk);
}
- (void)addPeal:(NSString *)peal
{
    NSLog(@"奶茶添加了：%@",peal);
}
- (void)addNatadecoco:(NSString *)natadecoco
{
    NSLog(@"奶茶添加了：%@",natadecoco);
}
- (void)addDrink
{
    NSLog(@"这是一杯超级棒的奶茶");
}
@end

• ViewController （客户端）

/**
 客户想要店主冲一杯带糖，加珍珠，加牛奶，加椰果的奶茶
 指挥者：店主
 构建者：奶茶
 生成者:糖,珍珠，牛奶，椰果
 */

#import "ViewController.h"
#import "Director.h"
#import "BuildMilkyTea.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    //第一种方式
    id <TeaBuilder> builder = [[BuildMilkyTea alloc] init];
    
    //构建者
    Director *director = [[Director alloc] initWithDirector:builder];
    [director contractWithDirector:@"5分糖" milk:@"纯牛奶" peal:@"黑珍珠" natadecoco:@"台湾椰果"];
    
    
    //第二种方式
    id <TeaBuilder> builder2 = [[BuildMilkyTea alloc] init];
    //构建者
    id <MilkGenerateProtocol> milk = [[[[[builder2 buildSugar:@"7分糖"] buildMilk:@"酸牛奶"] buildPearl:@"大黑珍珠"] buildNatadecoco:@"台湾椰果11"] drink];
    NSLog(@"milk======:%@",milk);
    

}
@end

• github完整代码：https://github.com/defuliu/BuilderPattern.git