前言

MJExtension是一套“字典和模型之間互相轉換”的輕量級框架

GitHub地址：https://github.com/CoderMJLee/MJExtension

MJExtension能完成的功能

字典 –> 模型 模型 –> 字典 字典數組 –> 模型數組

模型數組 –> 字典數組

具體用法主要參考 “NSObject+MJKeyValue.h”

---

實例

1.簡單的字典 -> 模型

//
//  MJUser.h
//  字典與模型的互轉
//  用戶模型
//

#import 

typedef enum {
    SexMale,
    SexFemale
} Sex;

@interface MJUser : NSObject
/** 名稱 */
@property (copy, nonatomic) NSString *name;
/** 頭像 */
@property (copy, nonatomic) NSString *icon;
/** 年齡 */
@property (assign, nonatomic) unsigned int age;
/** 身高 */
@property (strong, nonatomic) NSNumber *height;
/** 財富 */
@property (strong, nonatomic) NSDecimalNumber *money;
/** 性別 */
@property (assign, nonatomic) Sex sex;
/** 同性戀 */
@property (assign, nonatomic, getter=isGay) BOOL gay;

@end

/**
 *  簡單的字典 -> 模型
 */
void keyValues2object()
{
    // 1.定義一個字典
    NSDictionary *dict = @{
                           @"name" : @"Jack",
                           @"icon" : @"lufy.png",
                           @"age" : @"20",
                           @"height" : @1.55,
                           @"money" : @"100.9",
                           @"sex" : @(SexFemale),
                           @"gay" : @"1"
                       //  @"gay" : @"NO"
                       //  @"gay" : @"true"
                           };

    // 2.將字典轉為MJUser模型
    MJUser *user = [MJUser mj_objectWithKeyValues:dict];

    // 3.打印MJUser模型的屬性
    MJExtensionLog(@"name=%@, icon=%@, age=%zd, height=%@, money=%@, sex=%d, gay=%d", user.name, user.icon, user.age, user.height, user.money, user.sex, user.gay);
}

2.JSON字符串 -> 模型

/**
 *  JSON字符串 -> 模型
 */
void keyValues2object1()
{
    // 1.定義一個JSON字符串
    NSString *jsonString = @"{\"name\":\"Jack\", \"icon\":\"lufy.png\", \"age\":20, \"height\":333333.7}";

    // 2.將JSON字符串轉為MJUser模型
    MJUser *user = [MJUser mj_objectWithKeyValues:jsonString];

    // 3.打印MJUser模型的屬性
    MJExtensionLog(@"name=%@, icon=%@, age=%d, height=%@", user.name, user.icon, user.age, user.height);
}

3.復雜的字典 -> 模型 (模型裡面包含了模型)

//
//  MJStatus.h
//  字典與模型的互轉
//  微博模型
//

#import 
@class MJUser;

@interface MJStatus : NSObject
/** 微博文本內容 */
@property (copy, nonatomic) NSString *text;
/** 微博作者 */
@property (strong, nonatomic) MJUser *user;
/** 轉發的微博 */
@property (strong, nonatomic) MJStatus *retweetedStatus;

@end

/**
 *  復雜的字典 -> 模型 (模型裡面包含了模型)
 */
void keyValues2object2()
{
    // 1.定義一個字典
    NSDictionary *dict = @{
                           @"text" : @"是啊，今天天氣確實不錯！",

                           @"user" : @{
                                   @"name" : @"Jack",
                                   @"icon" : @"lufy.png"
                                   },

                           @"retweetedStatus" : @{
                                   @"text" : @"今天天氣真不錯！",

                                   @"user" : @{
                                           @"name" : @"Rose",
                                           @"icon" : @"nami.png"
                                           }
                                   }
                           };

    // 2.將字典轉為Status模型
    MJStatus *status = [MJStatus mj_objectWithKeyValues:dict];

    // 3.打印status的屬性
    NSString *text = status.text;
    NSString *name = status.user.name;
    NSString *icon = status.user.icon;
    MJExtensionLog(@"text=%@, name=%@, icon=%@", text, name, icon);

    // 4.打印status.retweetedStatus的屬性
    NSString *text2 = status.retweetedStatus.text;
    NSString *name2 = status.retweetedStatus.user.name;
    NSString *icon2 = status.retweetedStatus.user.icon;
    MJExtensionLog(@"text2=%@, name2=%@, icon2=%@", text2, name2, icon2);
}

4.復雜的字典 -> 模型 (模型的數組屬性裡面又裝著模型)

//
//  MJStatusResult.h
//  字典與模型的互轉
//  微博結果（用來表示大批量的微博數據）
//

#import "MJBaseObject.h"

@interface MJStatusResult : MJBaseObject
/** 存放著某一頁微博數據（裡面都是Status模型） */
@property (strong, nonatomic) NSMutableArray *statuses;
/** 存放著一堆的廣告數據（裡面都是MJAd模型） */
@property (strong, nonatomic) NSArray *ads;
/** 總數 */
@property (strong, nonatomic) NSNumber *totalNumber;
/** 上一頁的游標 */
@property (assign, nonatomic) long long previousCursor;
/** 下一頁的游標 */
@property (assign, nonatomic) long long nextCursor;

@end

//
//  MJStatusResult.m
//  字典與模型的互轉
//

#import "MJStatusResult.h"

@implementation MJStatusResult

+ (NSDictionary *)mj_objectClassInArray
{
    return @{
             @"statuses" : @"MJStatus",
             @"ads" : @"MJAd"
             };
}

@end

/**
 *  復雜的字典 -> 模型 (模型的數組屬性裡面又裝著模型)
 */
void keyValues2object3()
{
    // 1.定義一個字典
    NSDictionary *dict = @{
                           @"statuses" : @[
                                   @{
                                       @"text" : @"今天天氣真不錯！",

                                       @"user" : @{
                                               @"name" : @"Rose",
                                               @"icon" : @"nami.png"
                                               }
                                       },

                                   @{
                                       @"text" : @"明天去旅游了",

                                       @"user" : @{
                                               @"name" : @"Jack",
                                               @"icon" : @"lufy.png"
                                               }
                                       }

                                   ],

                           @"ads" : @[
                                   @{
                                       @"image" : @"ad01.png",
                                       @"url" : @"http://www.小碼哥ad01.com"
                                       },
                                   @{
                                       @"image" : @"ad02.png",
                                       @"url" : @"http://www.小碼哥ad02.com"
                                       }
                                   ],

                           @"totalNumber" : @"2014",
                           @"previousCursor" : @"13476589",
                           @"nextCursor" : @"13476599"
                           };

    // 2.將字典轉為MJStatusResult模型
    MJStatusResult *result = [MJStatusResult mj_objectWithKeyValues:dict];

    // 3.打印MJStatusResult模型的簡單屬性
    MJExtensionLog(@"totalNumber=%@, previousCursor=%lld, nextCursor=%lld", result.totalNumber, result.previousCursor, result.nextCursor);

    // 4.打印statuses數組中的模型屬性
    for (MJStatus *status in result.statuses) {
        NSString *text = status.text;
        NSString *name = status.user.name;
        NSString *icon = status.user.icon;
        MJExtensionLog(@"text=%@, name=%@, icon=%@", text, name, icon);
    }

    // 5.打印ads數組中的模型屬性
    for (MJAd *ad in result.ads) {
        MJExtensionLog(@"image=%@, url=%@", ad.image, ad.url);
    }
}

5.簡單的字典 -> 模型（key替換，比如ID和id，支持多級映射）

//
//  MJStudent.h
//  MJExtensionExample
//

#import 
@class MJBag;

@interface MJStudent : NSObject

@property (copy, nonatomic) NSString *ID;
@property (copy, nonatomic) NSString *otherName;
@property (copy, nonatomic) NSString *nowName;
@property (copy, nonatomic) NSString *oldName;
@property (copy, nonatomic) NSString *nameChangedTime;
@property (copy, nonatomic) NSString *desc;
@property (strong, nonatomic) MJBag *bag;
@property (strong, nonatomic) NSArray *books;

@end

/**
 * 簡單的字典 -> 模型（key替換，比如ID和id。多級映射，比如 oldName 和 name.oldName）
 */
void keyValues2object4()
{
    // 1.定義一個字典
    NSDictionary *dict = @{
                           @"id" : @"20",
                           @"desciption" : @"好孩子",
                           @"name" : @{
                                   @"newName" : @"lufy",
                                   @"oldName" : @"kitty",
                                   @"info" : @[
                                           @"test-data",
                                           @{@"nameChangedTime" : @"2013-08-07"}
                                           ]
                                   },
                           @"other" : @{
                                   @"bag" : @{
                                           @"name" : @"小書包",
                                           @"price" : @100.7
                                           }
                                   }
                           };

    // 2.將字典轉為MJStudent模型
    MJStudent *stu = [MJStudent mj_objectWithKeyValues:dict];

    // 3.打印MJStudent模型的屬性
    MJExtensionLog(@"ID=%@, desc=%@, otherName=%@, oldName=%@, nowName=%@, nameChangedTime=%@", stu.ID, stu.desc, stu.otherName, stu.oldName, stu.nowName, stu.nameChangedTime);
    MJExtensionLog(@"bagName=%@, bagPrice=%f", stu.bag.name, stu.bag.price);

    //    CFTimeInterval begin = CFAbsoluteTimeGetCurrent();
    //    for (int i = 0; i< 10000; i++) {
    //        [MJStudent mj_objectWithKeyValues:dict];
    //    }
    //    CFTimeInterval end = CFAbsoluteTimeGetCurrent();
    //    MJExtensionLog(@"%f", end - begin);
}

6.字典數組 -> 模型數組

//
//  MJUser.h
//  字典與模型的互轉
//  用戶模型

#import 

typedef enum {
    SexMale,
    SexFemale
} Sex;

@interface MJUser : NSObject
/** 名稱 */
@property (copy, nonatomic) NSString *name;
/** 頭像 */
@property (copy, nonatomic) NSString *icon;
/** 年齡 */
@property (assign, nonatomic) unsigned int age;
/** 身高 */
@property (strong, nonatomic) NSNumber *height;
/** 財富 */
@property (strong, nonatomic) NSDecimalNumber *money;
/** 性別 */
@property (assign, nonatomic) Sex sex;
/** 同性戀 */
@property (assign, nonatomic, getter=isGay) BOOL gay;

@end

/**
 *  字典數組 -> 模型數組
 */
void keyValuesArray2objectArray()
{
    // 1.定義一個字典數組
    NSArray *dictArray = @[
                           @{
                               @"name" : @"Jack",
                               @"icon" : @"lufy.png",
                               },

                           @{
                               @"name" : @"Rose",
                               @"icon" : @"nami.png",
                               }
                           ];

    // 2.將字典數組轉為MJUser模型數組
    NSArray *userArray = [MJUser mj_objectArrayWithKeyValuesArray:dictArray];

    // 3.打印userArray數組中的MJUser模型屬性
    for (MJUser *user in userArray) {
        MJExtensionLog(@"name=%@, icon=%@", user.name, user.icon);
    }
}

7.模型轉字典

/**
 *  模型 -> 字典
 */
void object2keyValues()
{
    // 1.新建模型
    MJUser *user = [[MJUser alloc] init];
    user.name = @"Jack";
    user.icon = @"lufy.png";

    MJStatus *status = [[MJStatus alloc] init];
    status.user = user;
    status.text = @"今天的心情不錯！";

    // 2.將模型轉為字典
    NSDictionary *statusDict = status.mj_keyValues;
    MJExtensionLog(@"%@", statusDict);

    MJExtensionLog(@"%@", [status mj_keyValuesWithKeys:@[@"text"]]);

    // 3.新建多級映射的模型
    MJStudent *stu = [[MJStudent alloc] init];
    stu.ID = @"123";
    stu.oldName = @"rose";
    stu.nowName = @"jack";
    stu.desc = @"handsome";
    stu.nameChangedTime = @"2018-09-08";
    stu.books = @[@"Good book", @"Red book"];

    MJBag *bag = [[MJBag alloc] init];
    bag.name = @"小書包";
    bag.price = 205;
    stu.bag = bag;

    NSDictionary *stuDict = stu.mj_keyValues;
    MJExtensionLog(@"%@", stuDict);
    MJExtensionLog(@"%@", [stu mj_keyValuesWithIgnoredKeys:@[@"bag", @"oldName", @"nowName"]]);
    MJExtensionLog(@"%@", stu.mj_JSONString);

    [MJStudent mj_referenceReplacedKeyWhenCreatingKeyValues:NO];
    MJExtensionLog(@"\n模型轉字典時，字典的key參考replacedKeyFromPropertyName等方法:\n%@", stu.mj_keyValues);
}

8.模型數組 -> 字典數組

/**
 *  模型數組 -> 字典數組
 */
void objectArray2keyValuesArray()
{
    // 1.新建模型數組
    MJUser *user1 = [[MJUser alloc] init];
    user1.name = @"Jack";
    user1.icon = @"lufy.png";

    MJUser *user2 = [[MJUser alloc] init];
    user2.name = @"Rose";
    user2.icon = @"nami.png";

    NSArray *userArray = @[user1, user2];

    // 2.將模型數組轉為字典數組
    NSArray *dictArray = [MJUser mj_keyValuesArrayWithObjectArray:userArray];
    MJExtensionLog(@"%@", dictArray);
}

9.CoreData示例

/**
 *  CoreData示例
 */
void coreData()
{
    NSDictionary *dict = @{
                           @"name" : @"Jack",
                           @"icon" : @"lufy.png",
                           @"age" : @20,
                           @"height" : @1.55,
                           @"money" : @"100.9",
                           @"sex" : @(SexFemale),
                           @"gay" : @"true"
                           };

    // 這個Demo僅僅提供思路，具體的方法參數需要自己創建
    NSManagedObjectContext *context = nil;
    MJUser *user = [MJUser mj_objectWithKeyValues:dict context:context];

    // 利用CoreData保存模型
    [context save:nil];

    MJExtensionLog(@"name=%@, icon=%@, age=%zd, height=%f, money=%@, sex=%d, gay=%d", user.name, user.icon, user.age, user.height, user.money, user.sex, user.gay);
}

10.NSCoding示例

//
//  MJBag.h
//  MJExtensionExample
//

#import 

@interface MJBag : NSObject

@property (copy, nonatomic) NSString *name;
@property (assign, nonatomic) double price;

@end

//
//  MJBag.m
//  MJExtensionExample
//

#import "MJBag.h"
#import "MJExtension.h"

@implementation MJBag
// NSCoding實現
MJExtensionCodingImplementation

//+ (NSArray *)mj_ignoredCodingPropertyNames
//{
//    return @[@"name"];
//}

@end

/**
 * NSCoding示例
 */
void coding()
{
    // 創建模型
    MJBag *bag = [[MJBag alloc] init];
    bag.name = @"Red bag";
    bag.price = 200.8;

    NSString *file = [NSTemporaryDirectory() stringByAppendingPathComponent:@"bag.data"];
    // 歸檔
    [NSKeyedArchiver archiveRootObject:bag toFile:file];

    // 解檔
    MJBag *decodedBag = [NSKeyedUnarchiver unarchiveObjectWithFile:file];
    MJExtensionLog(@"name=%@, price=%f", decodedBag.name, decodedBag.price);
}

11.統一轉換屬性名（比如駝峰轉下劃線）

//
//  MJDog.h
//  MJExtensionExample
//

#import 

@interface MJDog : NSObject

@property (copy, nonatomic) NSString *nickName;
@property (assign, nonatomic) double salePrice;
@property (assign, nonatomic) double runSpeed;

@end

/**
 *  統一轉換屬性名（比如駝峰轉下劃線）
 */
void replacedKeyFromPropertyName121()
{
    // 1.定義一個字典
    NSDictionary *dict = @{
                           @"nick_name" : @"旺財",
                           @"sale_price" : @"10.5",
                           @"run_speed" : @"100.9"
                           };

    // 2.將字典轉為MJUser模型
    MJDog *dog = [MJDog mj_objectWithKeyValues:dict];

    // 3.打印MJUser模型的屬性
    MJExtensionLog(@"nickName=%@, scalePrice=%f runSpeed=%f", dog.nickName, dog.salePrice, dog.runSpeed);
}

12.過濾字典的值（比如字符串日期處理為NSDate、字符串nil處理為@”“）

//
//  Book.h
//  MJExtensionExample
//

#import 
@class MJBox;

@interface MJBook : NSObject

@property (copy, nonatomic) NSString *name;
@property (copy, nonatomic) NSString *publisher;
@property (strong, nonatomic) NSDate *publishedTime;
@property (strong, nonatomic) MJBox *box;

@end

/**
 *  過濾字典的值（比如字符串日期處理為NSDate、字符串nil處理為@""）
 */
void newValueFromOldValue()
{
    // 1.定義一個字典
    NSDictionary *dict = @{
                           @"name" : @"5分鐘突破iOS開發",
                           @"publishedTime" : @"2011-09-10"
                           };

    // 2.將字典轉為MJUser模型
    MJBook *book = [MJBook mj_objectWithKeyValues:dict];

    // 3.打印MJUser模型的屬性
    MJExtensionLog(@"name=%@, publisher=%@, publishedTime=%@", book.name, book.publisher, book.publishedTime);
}