关于iPhone：努力使用RestKit映射对象和参考


Struggling with RestKit mapping object and references

这里是我的实体

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- HomeArticle
identifier
article (relationship)

- Article
identifier
title
subtitle
text
home (relationship)

我有一个看起来像这样的有效负载：

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[
    {
       "id":"1",
       "title":"A Nice Simple One",
       "subtitle":"Subtitle",
       "text":"text text text"
    },
    {
       "id":"2",
       "title":"A Nice Simple Two",
       "subtitle":"London",
       "text":"text text text"
    }
]

我正在尝试填充HomeArticle并同时创建关系，例如：

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RKObjectManager* objectManager = [RKObjectManager sharedManager];
    NSString *pathString = @"/get_news/";
    [objectManager loadObjectsAtResourcePath:pathString usingBlock:^(RKObjectLoader *loader) {
        loader.delegate = self;
        loader.objectMapping = [self myHomeArticleMapping];

        loader.onDidLoadObject = ^(id object) {
            ...
        };
    }];

- (RKManagedObjectMapping *) myHomeArticleMapping{
    if(_homeArticleMapping == nil){
        _homeArticleMapping = [RKManagedObjectMapping mappingForClass:[HomeArticle class] inManagedObjectStore:[[RKObjectManager sharedManager] objectStore]];
        [_homeArticleMapping mapKeyPath:@"id" toAttribute:@"identifier"];
        [_homeArticleMapping mapRelationship:@"article" withMapping:[self myArticleMapping]];
        [_homeArticleMapping connectRelationship:@"article" withObjectForPrimaryKeyAttribute:@"identifier"];
    }
}

- (RKManagedObjectMapping *) myArticleMapping{
    if(_articleMapping == nil){
        _articleMapping = [RKManagedObjectMapping mappingForClass:[Article class] inManagedObjectStore:[[RKObjectManager sharedManager] objectStore]];

        [_articleMapping mapKeyPath:@"id" toAttribute:@"identifier"];
        [_articleMapping mapKeyPath:@"title" toAttribute:@"title"];
        [_articleMapping mapKeyPath:@"subtitle" toAttribute:@"subtitle"];
        [_articleMapping mapKeyPath:@"text" toAttribute:@"text"];
    }
}

已填充" HomeArticle"的标识符，但未创建关系。
你有什么主意我能做到吗？
我正在处理的项目比较复杂，但我对其进行了简化以使其更加清晰。

解决方法

好吧，我设法完成这项工作的唯一方法是对方法中的有效负载进行重新工作：

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- (void)objectLoader:(RKObjectLoader*)loader willMapData:(inout id *)mappableData

我基本上是从有效载荷数组中创建了一个字典，将id作为键：

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- (void)objectLoader:(RKObjectLoader*)loader willMapData:(inout id *)mappableData {
    NSMutableArray *newsArray = [NSMutableArray arrayWithArray:(NSArray *)*mappableData];
    NSMutableDictionary *newData = [[NSMutableDictionary alloc] init];
    int elementNumber = [newsArray count];
    for(int i = 0 ; i < elementNumber ; i++){
        NSMutableDictionary *news = [NSMutableDictionary dictionaryWithDictionary:[newsArray objectAtIndex:i]];

        [newData setObject:news forKey:[news objectForKey:@"id"]];
    }
    *mappableData = newData;
}

结束，然后我像这样更改" HomeArticle"的映射：

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if(_homeArticleMapping == nil){
            _homeArticleMapping = [RKManagedObjectMapping mappingForClass:[HomeArticle class] inManagedObjectStore:[[RKObjectManager sharedManager] objectStore]];
        _homeArticleMapping.forceCollectionMapping = YES;
        [_homeArticleMapping mapKeyOfNestedDictionaryToAttribute:@"identifier"];
        _homeArticleMapping.primaryKeyAttribute = @"identifier";
        [_homeArticleMapping mapKeyPath:@"(identifier)"
                         toRelationship:@"article"
                            withMapping:[self myArticleMapping]];
 }

它可以工作，但我不太喜欢。

说我有一个与对手有关系的实体。我想将关系与另一个称为facebookMapping的映射进行映射。然后将映射添加到相应keyPath(或根名称)处的mappingProvider。

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RKManagedObjectMapping *gameEntryMapping = [RKManagedObjectMapping mappingForClass:[GameEntry class] inManagedObjectStore:[RKObjectManager sharedManager].objectStore];
RKManagedObjectMapping *facebookMapping = [RKManagedObjectMapping mappingForClass:[FacebookUser class] inManagedObjectStore:[RKObjectManager sharedManager].objectStore];
[gameEntryMapping mapRelationship:@"opponent" withMapping:facebookMapping];
[facebookMapping mapKeyPath:@"systemID" toAttribute:@"systemId"];
[facebookMapping mapKeyPath:@"name" toAttribute:@"name"];
[[RKObjectManager sharedManager].mappingProvider setMapping:gameEntryMapping forKeyPath:@"games"];
[[RKObjectManager sharedManager].mappingProvider addObjectMapping:gameEntryMapping];
[[RKObjectManager sharedManager] loadObjectsAtResourcePath:@"/syncGames" usingBlock:^(RKObjectLoader *loader) {
    loader.method = RKRequestMethodPOST;
    loader.params = params;
    loader.delegate = self;
}];