基本使用
涉想你的JSON数据像这样:
{ "id": "10", "country": "Germany", "dialCode": 49, "isInEurope": true }
- 为你的数据模型创建一个Objective-C的类，继承自JSONModel.
- 将JSON中的keys在.h文件中声明为属性:
#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文件中不需要做任何事情.
- 用数据初始化你的model:
#import "CountryModel.h" ... NSString* json = (fetch here JSON from Internet) ... NSError* err = nil; CountryModel* country = [[CountryModel alloc] initWithString:json error:&err];
举个例子
命名自动匹配
{
"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: 尖括号后 NSArray 包含一个协议. 这跟Objective-C原生的泛型不是一个概念. 他们不会冲突, 但对于JSONModel来说,协议必须在一个地方声明.
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
设置全局键映射(应用于所有model)
[JSONModel setGlobalKeyMapper:[
[JSONKeyMapper alloc] initWithDictionary:@{
@"item_id":@"ID",
@"item.name": @"itemName"
}]
];
设置下划线自动转驼峰
{
"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
可选属性 (就是说这个属性可以为null或者为空)
{
"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
忽略属性 (就是完全忽略这个属性)
{
"id": "123",
"name": null
}
@interface ProductModel : JSONModel
@property (assign, nonatomic) int id;
@property (strong, nonatomic) NSString<Ignore>* customProperty;
@end
@implementation ProductModel
@end
设置所有的属性为可选(所有属性值可以为空)
@implementation ProductModel
+(BOOL)propertyIsOptional:(NSString*)propertyName
{
return YES;
}
@end
使用JSONModel自带的 HTTP 请求
//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 ...
}];
将model转化为字典或者json格式的字符串
ProductModel* pm = [[ProductModel alloc] initWithString:jsonString error:nil]; pm.name = @"Changed Name"; //convert to dictionary NSDictionary* dict = [pm toDictionary]; //convert to text NSString* string = [pm toJSONString];
自定义数据的转换
@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
自定义处理指定的属性
@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
自定义JSON校验
@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