使用 RestKit 0.20 的对象映射关系

Posted 2023-03-16

【中文标题】使用 RestKit 0.20 的对象映射关系

【英文标题】：Object Mappings Relationship using RestKit 0.20

【发布时间】：2013-01-29 12:54:11

【问题描述】：

我尝试在我的 ios 应用程序中使用 RestKit 0.20 从服务器读取数据并收到以下错误：

//Error

`… I restkit:RKLog.m:34 RestKit logging initialized...`
`… I restkit.support:RKMIMETypeSerialization.m:115 JSON Serialization class 'RKNSJSONSerialization' detected: Registering for MIME Type 'application/json`
`... T restkit.network:RKHTTPRequestOperation.m:139 GET '(null)':
request.headers=
    Accept = "application/json";
    "Accept-Language" = "en, fr, de, ja, nl, it, es, pt, pt-PT, da, fi, nb, sv, ko, zh-Hans, zh-Hant, ru, pl, tr, uk, ar, hr, cs, el, he, ro, sk, th, id, ms, en-GB, ca, hu, vi, en-us;q=0.8";
    "User-Agent" = "XXXXX/1.0 (iPhone Simulator; iOS 5.0; Scale/1.00)";

request.body=(null)`

`... E restkit.network:RKHTTPRequestOperation.m:150 GET '(null)' (0):
error=Error Domain=NSURLErrorDomain Code=-1000 "bad URL" UserInfo=0x6c9d570 NSUnderlyingError=0x6c9d460 "bad URL", NSLocalizedDescription=bad URL
response.body=(null)`
`... E restkit.network:RKObjectRequestOperation.m:270 Object request failed: Underlying HTTP request operation failed with error: Error Domain=NSURLErrorDomain Code=-1000 "bad URL" UserInfo=0x6c9d570 NSUnderlyingError=0x6c9d460 "bad URL", NSLocalizedDescription=bad URL`

`... Hit error: Error Domain=NSURLErrorDomain Code=-1000 "bad URL" UserInfo=0x6c9d570 NSUnderlyingError=0x6c9d460 "bad URL", NSLocalizedDescription=bad URL`

这是从服务器收到的 JSON：

[ 
    "array1" : [ 
    "a1prop1" : 1,
    "a1prop2" : "prop21val",
   , 
     "a1prop1" : 2,
     "a1prop2" : "prop22val",
    , 
     "a1prop1" : 3,
     "a1prop2" : "prop23val",
     ],
  "property1" : prop1val,
  "property2" : "prop2val",
  "property3" : "prop3val",
 ]

使用 RestKit 的映射：

-(void) getData 
………………...
NSURL *baseURL = [NSURL URLWithString:stringURL];

AFHTTPClient* client = [[AFHTTPClient alloc] initWithBaseURL:baseURL];
[client setDefaultHeader:@"Accept" value:RKMIMETypeJSON];

RKObjectManager *objectManager = [[RKObjectManager alloc] initWithHTTPClient:client];
[objectManager setAcceptHeaderWithMIMEType:RKMIMETypeJSON];

RKObjectMapping *array1Mapping = [RKObjectMapping mappingForClass:[ArrayOneClass class]];
[array1Mapping addAttributeMappingsFromDictionary:@
 @"a1Prop1" : @"a1Prop1",
 @"a1Prop2" : @"a1Prop2",
 ];

RKObjectMapping *mainObjectMapping = [RKObjectMapping mappingForClass:[MainObjectClass class]]
[mainObjectMapping addAttributeMappingsFromDictionary:@
 @"property1" : @"property1",
 @"property2" : @"property2",
 @"property3" : @"property3",
 ];

RKRelationshipMapping *mainObjRelationMapping = [RKRelationshipMapping relationshipMappingFromKeyPath:@"array1" toKeyPath:@"array1" withMapping:array1Mapping];
[mainObjectMapping addRelationshipMappingWithSourceKeyPath:@"array1" mapping: mainObjRelationMapping.mapping];

RKResponseDescriptor *responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:mainObjectMapping pathPattern:nil
                                                                                       keyPath:nil
                                                                                   statusCodes:[NSIndexSet indexSetWithIndex:200]];
[objectManager addResponseDescriptor:responseDescriptor];

NSString *pathStr = [NSString stringWithFormat:@"/api/getAllObjects"];

[objectManager getObjectsAtPath:pathStr
                     parameters:nil
                        success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) 
                            NSLog(@"...success");
                        
                        failure:^(RKObjectRequestOperation *operation, NSError *error) 
                            NSLog(@"Hit error: %@", error);
                        ];

MainObject 类：

//MainObjectClass.h

    @interface MainObjectClass : NSObject
     int property1;
     NSString * property2;
     NSString * property3;
     NSSet *array1;
    

@property (nonatomic) int property1;
@property (nonatomic, retain) NSString * property2;
@property (nonatomic, retain) NSString * property3;
@property (nonatomic, retain) NSSet *array1;

- (NSDictionary*)elementToPropertyMappings;
- (NSDictionary*)elementToRelationshipMappings;
@end

//MainObjectClass.m

@implementation MainObjectClass

@synthesize property1, property2, property3, array1;
- (NSDictionary*)elementToPropertyMappings 
    return [NSDictionary dictionaryWithObjectsAndKeys:
        @"property1", @"property1",
        @"property2", @"property2",
        @"property3", @"property3",
        nil];

- (NSDictionary *)elementToRelationshipMappings 
    return [NSDictionary dictionaryWithObjectsAndKeys:
        @"array1", @"array1",
        nil];

@end

谁能告诉我为什么这没有产生正确的请求？它根本没有击中服务器。我尝试了没有关系映射的简单 get/post 方法，它们都可以正常使用 RestKit 映射。欣赏您的观点。谢谢。

【问题讨论】：

错误的 URL，表示您发布到的 URL 有问题。您能否在问题中添加一些有关您正在使用的 URL 的其他详细信息？

【参考方案1】：

试试这个：- 使用RKObjectManager的属性

objectManager.serializationMIMEType = RKMIMETypeJSON;