Question

我在iOS上使用RestKit从kraken.com中检索一些数据

我有以下JSON数据：

{
    "error":[],
    "result":{
        "XXBTZUSD":{
            "a":["475.00000","1"],
            "b":["465.00639","2"],
            "c":["475.00000","0.01000389"],
            "v":["1.01078477","1.01078477"],
            "p":["475.00008","475.00008"],
            "t":[6,6],
            "l":["475.00000","475.00000"],
            "h":["475.00013","475.00013"],
            "o":"475.00001"
        }
    }
}

我的keyPath是@"result.XXBTZUSD"，我对每个属性中数组的第一个成员感兴趣，即'a'，'b'，'c'等等除'o'之外的其他值，因为它的值不是数组。需要明确的是，我感兴趣的示例值"475.00000"为'a'。我正在尝试将这些值映射到我自己的数据模型中的NSNumber属性。

除了：我会动态地这样做，因为我也从其他来源获得类似的数据，但具有不同的结构化数据。

另外，我不相信我可以使用RKObjectMappingMatcher因为我没有预期价值＆＃34;对于这些数据。

修改

我继续处理RKDynamicMapping和RKBlockValueTransformer逻辑：

RKDynamicMapping *dynamicMapping = [RKDynamicMapping new];
[dynamicMapping setObjectMappingForRepresentationBlock:^RKObjectMapping *(id representation)
{
    RKObjectMapping *mapping = [RKObjectMapping mappingForClass:class];

    if ([url.absoluteString isEqualToString:@"https://api.kraken.com"])
    {
        RKBlockValueTransformer *arrayToNumberValueTransformer = [RKBlockValueTransformer valueTransformerWithValidationBlock:^BOOL(__unsafe_unretained Class inputValueClass, __unsafe_unretained Class outputValueClass) {
            BOOL isTransformableValue = NO;
            if ([inputValueClass isSubclassOfClass:[NSArray class]] && [outputValueClass isSubclassOfClass:[NSNumber class]])
            {
                isTransformableValue = YES;
            }
            return isTransformableValue;
        } transformationBlock:^BOOL(id inputValue, __autoreleasing id *outputValue, __unsafe_unretained Class outputClass, NSError *__autoreleasing *error) {
            RKValueTransformerTestInputValueIsKindOfClass(inputValue, [NSArray class], error);
            RKValueTransformerTestOutputValueClassIsSubclassOfClass(outputClass, [NSNumber class], error);

            *outputValue = [[NSNumber alloc] initWithDouble:[[inputValue objectAtIndex:0] doubleValue]];

            return YES;
        }];

        arrayToNumberValueTransformer.name = @"ArrayToNumberValueTransformer";
        [[RKValueTransformer defaultValueTransformer] insertValueTransformer:arrayToNumberValueTransformer atIndex:0];
    }

    if (sourceKeyPath && [sourceKeyPath length] > 0)
    {
        //  Special case (ignore):
        if ([url.absoluteString isEqualToString:@"http://blockchain.info"])
        {
            [mapping addAttributeMappingsFromDictionary:@{sourceKeyPath:@"currencyCode"}];
        }

        //
        //  The following is useful if you're expecting a set but the service returns a single value
        //[mapping setForceCollectionMapping:YES];    // RestKit cannot infer this information on its own
        //
    }

    //  Where a 'key' is the JSON representation and its value is the internal object representation
    NSDictionary *attributeMappings = [query objectForKey:@"attributeMappings"];
    [mapping addAttributeMappingsFromDictionary:attributeMappings];

    return mapping;
}];

修改

我现在已经映射了数据但是我不确定我是否正确地将RKBlockValueTransformer插入到默认值变换器列表中？如果我在0插入，我会破坏其他默认值变换器的功能吗？

定位JSON内部数组数据并在RestKit中使用RKValueTransformer

0 个答案: