Restkit: object mapping with xml

Question

I try to map the response xml into object and the xml looks like:

<list version="1.0">
  <meta>
    <type>resource-list</type>
  </meta>
  <resources start="0" count="168">
    <resource classname="Quote">
      <field name="name">Alpha</field>
      <field name="price">10</field>
    </resource>
    <resource classname="Quote">
      <field name="name">Beta</field>
      <field name="price">9</field>
    </resource>
  </resources>
</list>

What I want is resources part. I create the object model:

@interface Field : NSObject
@property (nonatomic, strong) NSString *name;
@property (nonatomic, strong) NSNumber *price;
@end
@interface Resources : NSObject
@property (nonatomic, strong) NSNumber *count;
@property (nonatomic, strong) NSArray *resource;
@end

The problem is : I don't know how to set the mapping for resource of Resources. I once tried using mapping:

RKObjectMapping *objMapping = [RKObjectMapping mappingForClass:[Field class]];
[objMapping addAttributeMappingsFromArray:@[@"name",@"price"]];</br>

RKObjectMapping *resourcesMapping = [RKObjectMapping mappingForClass:[Resources class]];
[resourcesMapping addAttributeMappingsFromArray:@[@"count"]];
[resourcesMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"resource" toKeyPath:nil withMapping:objMapping]];

RKResponseDescriptor *descriptor = [RKResponseDescriptor responseDescriptorWithMapping:resourcesMapping method:RKRequestMethodGET pathPattern:@"XXXXXX" keyPath:@"list.resources" statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];

After the mapping is finished, the Resources object is created. However the array resource of it is still nil.

How can I get the array of resource in the xml?
---Updated-----
I updated the code, which is

RKObjectMapping *objMapping = [RKObjectMapping mappingForClass:[Field class]];
objMapping.forceCollectionMapping = YES;
[objMapping addAttributeMappingsFromDictionary:@{@"name":@"name.text"}];  

I also update the respondscripter with keypath:

RKResponseDescriptor *descriptor = [RKResponseDescriptor responseDescriptorWithMapping:objMapping method:RKRequestMethodGET pathPattern:@"XXXXX" keyPath:@"list.resources.resource.field" statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];  

Then in the success block of RKObjectManager, the mapping results have the field array. The problem is the Field's property are all nil.
I check the log which looks:

D restkit.object_mapping:RKMapperOperation.m:229 Asked to map source object (
        {
        name = name;
        text = "alpha";
    },
        {
        name = price;
        text = "98.3";
    }

) with mapping  name.text>"
)>
2014-05-14 23:33:57.681 RestKitTest[5138:3307] D restkit.object_mapping:RKMappingOperation.m:859 Starting mapping operation...
2014-05-14 23:33:57.682 RestKitTest[5138:3307] W restkit.object_mapping:RKMappingOperation.m:338 Destination object  rejected attribute value (
    name,
    price
) for keyPath name.text. Skipping...

It seems that the attribute of the xml becomes a value of the map source object. How I set the configuration to parse this kind of object?

Answer 1

If you want to use the Resources wrapper object (you don't need to) then your response descriptor is drilling too deep into the incoming data, the key path should just be list. Turning on trace logging will help you to see how the XML is decoded and thus what keys you should be using. I don't use XML very often and find mapping the XML to keys directly quite difficult.

Note also that the XML decoding will usually add all of the found content into text keys, so rather than using name as the key you will need to use name.text (and thus you will need a dictionary to specify the source key path and the destination key).