Wie werden Objekte in Restkit gemappt, wenn die Antwort für einen Schlüssel zwischen Wörterbuch und String wechselt?

Question

Ich habe Schwierigkeiten beim Zuordnen eines Objekts in Restkit, das verschachtelt ist. Die Antwort lautet wie folgt:

{ 
    "status": "SUCCESS", 
    "message": "Newsfeeds loaded successfully", 
    "links": { 
    "self": "" 
    }, 
    "newsfeeds": [ 
    { 
     "type": "post", 
     "content": { 
     "id": "39ff4ea6-71d4-4d9c-872b-94d878ec54fd", 
     "owner_id": "75c72102-d7dc-44c6-bb62-c48b487897c4", 
     "owner_firstname": "Goran", 
     "owner_lastname": "Don", 
     "owner_profilephoto": "88f5930b-e779-47ac-86b7-4f31cd0d82aa.jpg", 
     "contents": [ 
      { 
      "type": "text", 
      "content": "Being the richest man in the cemetery doesn't matter to me. Going to bed at night saying we've done something wonderful, that's what matters to me.\n  Sometimes when you innovate, you make mistakes. It is best to admit them quickly, and get on with improving your other innovations" 
      }, 
      { 
      "type": "url", 
      "content": { 
       "title": "Beautiful landscape view  Of New Zealand and Australia is available here", 
       "position": "landscape", 
       "url": "39ff4ea6-71d4-4d9c-872b-94d878ec54fd/Img_62151fbd-119f-4a84-91a9-f37bfa6293db.jpg" 
      } 
      } 
     ], 
     "postdatetime": "May 18 2016 12:18:54.442 UTC", 
     "selfLike": false, 
     "likes": 0, 
     "comments": 0, 
     "starred": "false" 
     } 
    }, 
    { 
     "type": "post", 
     "content": { 
     "id": "7117d132-1811-4ac7-bfaf-bbb397eefb10", 
     "owner_id": "75c72102-d7dc-44c6-bb62-c48b487897c4", 
     "owner_firstname": "Goran", 
     "owner_lastname": "Don", 
     "owner_profilephoto": "88f5930b-e779-47ac-86b7-4f31cd0d82aa.jpg", 
     "contents": [ 
      { 
      "type": "text", 
      "content": "Hi this is a test" 
      } 
     ], 
     "postdatetime": "May 18 2016 11:42:24.978 UTC", 
     "selfLike": false, 
     "likes": 0, 
     "comments": 0, 
     "starred": "false" 
     } 
    }, 
    { 
     "type": "post", 
     "content": { 
     "id": "fbeb20cf-c87b-40db-9753-9fa32aac921a", 
     "owner_id": "75c72102-d7dc-44c6-bb62-c48b487897c4", 
     "owner_firstname": "Goran", 
     "owner_lastname": "Don", 
     "owner_profilephoto": "88f5930b-e779-47ac-86b7-4f31cd0d82aa.jpg", 
     "contents": [ 
      { 
      "type": "url", 
      "content": { 
       "title": "", 
       "position": "potrait", 
       "url": "fbeb20cf-c87b-40db-9753-9fa32aac921a/Img_23771f1c-bb22-4335-ae3f-4e83d97c5c3c.jpg" 
      } 
      }, 
      { 
      "type": "url", 
      "content": { 
       "title": "", 
       "position": "landscape", 
       "url": "fbeb20cf-c87b-40db-9753-9fa32aac921a/Img_a77e8349-b531-4d9d-944e-88971298c6fa.jpg" 
      } 
      } 
     ], 
     "postdatetime": "May 18 2016 07:39:07.937 UTC", 
     "selfLike": true, 
     "likes": 1, 
     "comments": 0, 
     "starred": "false" 
     } 
    }, 
    { 
     "type": "post", 
     "content": { 
     "id": "71e005a1-71ec-4131-8131-bfd38337ec6a", 
     "owner_id": "75c72102-d7dc-44c6-bb62-c48b487897c4", 
     "owner_firstname": "Goran", 
     "owner_lastname": "Don", 
     "owner_profilephoto": "88f5930b-e779-47ac-86b7-4f31cd0d82aa.jpg", 
     "contents": [ 
      { 
      "type": "url", 
      "content": { 
       "title": "", 
       "position": "potrait", 
       "url": "post/71e005a1-71ec-4131-8131-bfd38337ec6a/Img_600f6fd0-14f9-4bf3-af6e-f36b7ffedbc6.jpg" 
      } 
      } 
     ], 
     "postdatetime": "May 18 2016 07:27:53.278 UTC", 
     "selfLike": false, 
     "likes": 0, 
     "comments": 0, 
     "starred": "false" 
     } 
    } 
    ] 
} 

Aus dem Vorstehenden müssen „Inhalt“ innerhalb „Inhalt“ Array erreichen. "Inhalt" manchmal String und manchmal Wörterbuch zurück. Ich versuche wie folgt zuzuordnen:

RKObjectMapping * newsFeedMappingObject = [RKObjectMapping mappingForClass:[NewsFeed class]]; 

[newsFeedMappingObject addAttributeMappingsFromDictionary:@{@"type" : @"type",}]; 

RKObjectMapping * responseMappingObject = [RKObjectMapping mappingForClass:[ResponseMessage class]]; 

[responseMappingObject addAttributeMappingsFromDictionary:@{uStatus: @"status",uMessage: @"message",}]; 
[responseMappingObject addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"newsfeeds" 
                        toKeyPath:@"newsfeeds" 
                       withMapping:newsFeedMappingObject]]; 

RKObjectMapping * contentMappingObject = [RKObjectMapping mappingForClass:[Content class]]; 

[contentMappingObject addAttributeMappingsFromDictionary:@{@"id": @"contentId"}]; 

[newsFeedMappingObject addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"content" 
                         toKeyPath:@"cont" 
                        withMapping:contentMappingObject]]; 

RKObjectMapping * postContentMappingObject = [RKObjectMapping mappingForClass:[PostContent class]]; 

[postContentMappingObject addAttributeMappingsFromDictionary:@{@"type": @"type",}]; 

[contentMappingObject addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"contents" 
                        toKeyPath:@"contents" 
                        withMapping:postContentMappingObject]]; 

RKObjectMapping * postMappingObject = [RKObjectMapping mappingForClass:[Post class]]; 

[postMappingObject addAttributeMappingsFromDictionary:@{@"title":@"title"}]; 

[postContentMappingObject addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"content" 
                        toKeyPath:@"post" 
                        withMapping:postMappingObject]]; 

Wenn ich es die App stürzt mit log laufen wie: ** * Beenden app aufgrund nicht abgefangene Ausnahme 'NSUnknownKeyException', Grund: ‚[< __NSCFString 0x7fa302826d30> valueForUndefinedKey: ]: Diese Klasse ist nicht Schlüsselcodierung-kompatibel für den Schlüsseltitel. '

Ich versuche meine Hände auf dynamisches Mapping. Aber ich glaube, ich bin es falsch zu machen:

RKObjectMapping * newsFeedMappingObject = [RKObjectMapping mappingForClass:[NewsFeed class]]; 
    [newsFeedMappingObject addAttributeMappingsFromDictionary:@{ 
                   @"type" : @"type", 
                  }]; 

    RKObjectMapping * responseMappingObject = [RKObjectMapping mappingForClass:[ResponseMessage class]]; 
    [responseMappingObject addAttributeMappingsFromDictionary:@{ 
                  uStatus: @"status", 
                  uMessage: @"message", 
                  }]; 
    [responseMappingObject addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"newsfeeds" 
                         toKeyPath:@"newsfeeds" 
                        withMapping:newsFeedMappingObject]]; 



    RKObjectMapping * contentMappingObject = [RKObjectMapping mappingForClass:[Content class]]; 
    [contentMappingObject addAttributeMappingsFromDictionary:@{ 
                   @"id": @"contentId", 
                   }]; 
    [newsFeedMappingObject addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"content" 
                          toKeyPath:@"cont" 
                         withMapping:contentMappingObject]]; 


    RKObjectMapping * postContentMappingObject = [RKObjectMapping mappingForClass:[PostContent class]]; 
    [postContentMappingObject addAttributeMappingsFromDictionary:@{ 
                   @"type": @"type", 
                   }]; 
    [contentMappingObject addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"contents" 
                         toKeyPath:@"contents" 
                         withMapping:postContentMappingObject]]; 




    RKObjectMapping * postMappingObject = [RKObjectMapping mappingForClass:[Post class]]; 
    [postMappingObject addAttributeMappingsFromDictionary:@{ 
                  @"title" : @"title" 
        }]; 

    RKDynamicMapping* dynamicMapping = [RKDynamicMapping new]; 
    [postMappingObject addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"post" toKeyPath:@"content" withMapping:dynamicMapping]]; 


    // Connect a response descriptor for our dynamic mapping 
    RKResponseDescriptor *dynamicResponseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:dynamicMapping method:RKRequestMethodAny pathPattern:nil keyPath:@"content" statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)]; 
    [[RKObjectManager sharedManager] addResponseDescriptor:dynamicResponseDescriptor]; 


    // Option 2: Configure the dynamic mapping via a block 
    [dynamicMapping setObjectMappingForRepresentationBlock:^RKObjectMapping *(id representation) { 
     if ([[representation valueForKey:@"content"] isKindOfClass:[NSDictionary class]]) { 
      return postMappingObject; 
     } 
     return nil; 
    }]; 

    [postContentMappingObject addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"content" 
                         toKeyPath:@"post" 
                         withMapping:postMappingObject]]; 



    NSString *urlString = [NSString stringWithFormat:@"%@%@%@&userId=%@&startDate=%@&count=%d&scanForward=%@",uServiceUrl,uGetNewsFeedsRequest,accountId,userId,startDate,count,isForward]; 
    NSString* encodedUrl = [urlString stringByAddingPercentEncodingWithAllowedCharacters: 
          [NSCharacterSet URLQueryAllowedCharacterSet]]; 
    NSURL *getNewsRequestUrl = [NSURL URLWithString:encodedUrl]; 

    RKResponseDescriptor *responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:responseMappingObject method:RKRequestMethodAny pathPattern:nil keyPath:@"" statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)]; 

    [self getWithUrlString:getNewsRequestUrl withMappingObject:responseMappingObject andResponseDescriptors:@[responseDescriptor, dynamicResponseDescriptor] withSuccess:successBlock withFail:failBlock]; 

Answer 1

Sie müssen postMappingObject ändern eine Instanz von RKDynamicMapping zu sein, der die Daten überprüft, die sie mit versehen ist, was es zu sehen ist, und gibt eine entsprechende Zuordnung, die tatsächlich sein wird, verwendet, um diese Daten zu verarbeiten. Die Überprüfung soll feststellen, ob die Nutzlast eine Zeichenkette oder ein Wörterbuch ist.