Question

如何将多个对象映射到一个JSON对象？

这是我的两个对象

#import <RestKit/RestKit.h>

@interface Account : NSObject
@property NSInteger id;
@property NSString* secret;
@end
@implementation Account @end

@interface Entry : NSObject
@property NSString* name;
@end
@implementation Entry @end

我希望将这些对象映射到以下JSON：

    /* Goal JSON:
     {
     "id":10,
     "secret":"supersecret",
     "eventName":"Hayooo"
     }
     */

首先尝试直接使用RKMapperOperation：

void testMergeMap(){
    Account* account = [Account new];
    account.id = 10;
    account.secret = @"supersecret";

    Entry* entry = [Entry new];
    entry.name = @"Hayooo";

    RKMapperOperation* mapper = [[RKMapperOperation alloc]
                                 initWithRepresentation:@{@"account":account, @"entry":entry} mappingsDictionary:@{@"account.id": @"id", @"account.secret":@"secret", @"entry.name":@"eventName"}];
    [mapper start];
    RKMappingResult* result = mapper.mappingResult;
    NSLog(@"%@", result.dictionary.description);
}

但是那次崩溃，无法真正造成错误。

那么，我应该怎么做呢？

修改

我也试过这个

RKObjectManager* testSimpleMap(Account* account, Entry* entry){
    RKObjectMapping* map = [RKObjectMapping requestMapping];
    [map addAttributeMappingsFromDictionary:
     @{@"account.id": @"id",
       @"account.secret": @"secret",
       @"entry.name":@"eventName"}];

    RKObjectManager* man = [RKObjectManager managerWithBaseURL:[NSURL URLWithString:@"http://google.com"]];
    RKRequestDescriptor* requestDescriptor = [RKRequestDescriptor requestDescriptorWithMapping:map objectClass:nil rootKeyPath:nil method:RKRequestMethodPOST];
    [man addRequestDescriptor:requestDescriptor];
    [man postObject:@{@"account":account, @"entry":entry} path:@"/" parameters:nil success:nil failure:nil];

    return man;
}

但是我们不能在没有类的情况下创建requestDescriptors，因此不起作用。但我认为了解我的目标是有用的。如果这样可行，那就太好了！

Answer 1

mappingsDictionary:不应该是纯字符串键和值的字典。键应该是要映射的项的关键路径，值应该是RKMapping个实例，用于描述如何映射在关键路径中找到的数据。

一般来说，如果你刚开始我不会直接使用RKMapperOperation。我会考虑使用RKObjectManager。它抽象你远离这样的内在细节。

如果您想继续使用的内容，请查看示例in the docs。

Answer 2

创建一个模拟关系的第三个对象，但我觉得它不够优雅。

@interface Both : NSObject
@property Account* account;
@property Entry* entry;
@end
@implementation Both @end

RKObjectManager* testRelationMap(Account* account, Entry* entry){
    /* Goal JSON:
     {
        "user":{
             "id":10,
             "secret":"supersecret",
        },
        "entry":{
            "name":"Hayooo"
        }
     }
     */

    Both* both = [Both new];
    both.account = account;
    both.entry = entry;

    RKObjectMapping* accountMap = [RKObjectMapping requestMapping];
    [accountMap addAttributeMappingsFromArray:@[@"id", @"secret"]];

    RKObjectMapping* entryMap = [RKObjectMapping requestMapping];
    [entryMap addAttributeMappingsFromArray:@[@"name"]];

    RKObjectMapping* relationMap = [RKObjectMapping requestMapping];
    [relationMap addRelationshipMappingWithSourceKeyPath:@"account" mapping:accountMap];
    [relationMap addRelationshipMappingWithSourceKeyPath:@"entry" mapping:entryMap];

    RKObjectManager* man = [RKObjectManager managerWithBaseURL:[NSURL URLWithString:@"http://google.com"]];
    RKRequestDescriptor* requestDescriptor = [RKRequestDescriptor requestDescriptorWithMapping:relationMap objectClass:[Both class] rootKeyPath:nil method:RKRequestMethodPOST];
    [man addRequestDescriptor:requestDescriptor];
    [man postObject:both path:@"/" parameters:nil success:nil failure:nil];
    return man;
}

这种方式需要很多代码，但这是一个解决方案。

合并RestKit的对象

2 个答案: