iOS 中JSONModel的使用

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涉想你的JSON資料像這樣:

{ "id": "10", "country": "Germany", "dialCode": 49, "isInEurope": true }

• 為你的資料模型建立一個Objective-C的類，繼承自JSONModel.
• 將JSON中的keys在.h檔案中聲明為屬性:

#import "JSONModel.h"@interface CountryModel : JSONModel@property (assign, nonatomic) int id;@property (strong, nonatomic) NSString* country;@property (strong, nonatomic) NSString* dialCode;@property (assign, nonatomic) BOOL isInEurope;@end

在.m檔案中不需要做任何事情.

• 用資料初始化你的model:

#import "CountryModel.h"...NSString* json = (fetch here JSON from Internet) ...NSError* err = nil;CountryModel* country = [[CountryModel alloc] initWithString:json error:&err];

舉個例子命名自動匹配

{  "id": "123",  "name": "Product name",  "price": 12.95}

@interface ProductModel : JSONModel@property (assign, nonatomic) int id;@property (strong, nonatomic) NSString* name;@property (assign, nonatomic) float price;@end@implementation ProductModel@end

模型嵌套 (模型包含其他模型)

{  "order_id": 104,  "total_price": 13.45,  "product" : {    "id": "123",    "name": "Product name",    "price": 12.95  }}@interface OrderModel : JSONModel@property (assign, nonatomic) int order_id;@property (assign, nonatomic) float total_price;@property (strong, nonatomic) ProductModel* product;@end@implementation OrderModel@end

模型集合

{  "order_id": 104,  "total_price": 103.45,  "products" : [    {      "id": "123",      "name": "Product #1",      "price": 12.95    },    {      "id": "137",      "name": "Product #2",      "price": 82.95    }  ]}

@protocol ProductModel@end@interface ProductModel : JSONModel@property (assign, nonatomic) int id;@property (strong, nonatomic) NSString* name;@property (assign, nonatomic) float price;@end@implementation ProductModel@end@interface OrderModel : JSONModel@property (assign, nonatomic) int order_id;@property (assign, nonatomic) float total_price;@property (strong, nonatomic) NSArray<ProductModel>* products;@end@implementation OrderModel@end

注意: 角括弧後 NSArray 包含一個協議. 這跟Objective-C原生的泛型不是一個概念. 他們不會衝突, 但對於JSONModel來說,協議必須在一個地方聲明.

key映射

{  "order_id": 104,  "order_details" : [    {      "name": "Product#1",      "price": {        "usd": 12.95      }    }  ]}@interface OrderModel : JSONModel@property (assign, nonatomic) int id;@property (assign, nonatomic) float price;@property (strong, nonatomic) NSString* productName;@end@implementation OrderModel+(JSONKeyMapper*)keyMapper{  return [[JSONKeyMapper alloc] initWithDictionary:@{    @"order_id": @"id",    @"order_details.name": @"productName",    @"order_details.price.usd": @"price"  }];}@end

設定全域鍵映射(應用於所有model)

[JSONModel setGlobalKeyMapper:[    [JSONKeyMapper alloc] initWithDictionary:@{      @"item_id":@"ID",      @"item.name": @"itemName"   }]];

設定底線自動轉駝峰

{  "order_id": 104,  "order_product" : @"Product#1",  "order_price" : 12.95}

@interface OrderModel : JSONModel@property (assign, nonatomic) int orderId;@property (assign, nonatomic) float orderPrice;@property (strong, nonatomic) NSString* orderProduct;@end@implementation OrderModel+(JSONKeyMapper*)keyMapper{  return [JSONKeyMapper mapperFromUnderscoreCaseToCamelCase];}@end

可選屬性 (就是說這個屬性可以為null或者為空白)

{  "id": "123",  "name": null,  "price": 12.95}

@interface ProductModel : JSONModel@property (assign, nonatomic) int id;@property (strong, nonatomic) NSString<Optional>* name;@property (assign, nonatomic) float price;@property (strong, nonatomic) NSNumber<Optional>* uuid;@end@implementation ProductModel@end

忽略屬性 (就是完全忽略這個屬性)

{  "id": "123",  "name": null}@interface ProductModel : JSONModel@property (assign, nonatomic) int id;@property (strong, nonatomic) NSString<Ignore>* customProperty;@end@implementation ProductModel@end

設定所有的屬性為可選(所有屬性值可以為空白)

@implementation ProductModel+(BOOL)propertyIsOptional:(NSString*)propertyName{  return YES;}@end

使用JSONModel內建的 HTTP 要求

//add extra headers[[JSONHTTPClient requestHeaders] setValue:@"MySecret" forKey:@"AuthorizationToken"];//make post, get requests[JSONHTTPClient postJSONFromURLWithString:@"http://mydomain.com/api"                                   params:@{@"postParam1":@"value1"}                               completion:^(id json, JSONModelError *err) {                                   //check err, process json ...                               }];

將model轉化為字典或者json格式的字串

ProductModel* pm = [[ProductModel alloc] initWithString:jsonString error:nil];pm.name = @"Changed Name";//convert to dictionaryNSDictionary* dict = [pm toDictionary];//convert to textNSString* string = [pm toJSONString];

自訂資料的轉換

@implementation JSONValueTransformer (CustomTransformer)- (NSDate *)NSDateFromNSString:(NSString*)string {    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];    [formatter setDateFormat:APIDateFormat];    return [formatter dateFromString:string];}- (NSString *)JSONObjectFromNSDate:(NSDate *)date {    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];    [formatter setDateFormat:APIDateFormat];    return [formatter stringFromDate:date];}@end

自訂處理指定的屬性

@interface ProductModel : JSONModel@property (assign, nonatomic) int id;@property (strong, nonatomic) NSString* name;@property (assign, nonatomic) float price;@property (strong, nonatomic) NSLocale *locale;@end@implementation ProductModel// Convert and assign the locale property- (void)setLocaleWithNSString:(NSString*)string {    self.locale = [NSLocale localeWithLocaleIdentifier:string];}- (NSString *)JSONObjectForLocale {    return self.locale.localeIdentifier;}@end

自訂JSON校正

@interface ProductModel : JSONModel@property (assign, nonatomic) int id;@property (strong, nonatomic) NSString* name;@property (assign, nonatomic) float price;@property (strong, nonatomic) NSLocale *locale;@property (strong, nonatomic) NSNumber <Ignore> *minNameLength;@end@implementation ProductModel- (BOOL)validate:(NSError *__autoreleasing *)error {    BOOL valid = [super validate:error];    if (self.name.length < self.minNameLength.integerValue) {        *error = [NSError errorWithDomain:@"me.mycompany.com" code:1 userInfo:nil];        valid = NO;    }    return valid;}@end

iOS 中JSONModel的使用