gistfile1.txt

    RKObjectMapping* channelMapping = [RKObjectMapping mappingForClass:[Channel class]];
    [channelMapping mapKeyPath:@"id" toAttribute:@"identifier"];
    [channelMapping mapKeyPath:@"name" toAttribute:@"name"];
    [channelMapping mapKeyPath:@"num_of_listeners" toAttribute:@"numOfListeners"];

    //object mapping for GETs
    [[RKObjectManager sharedManager].mappingProvider setMapping:channelMapping forKeyPath:@"channels"];
    
    //set up object serialization for POSTing back to rails
    RKObjectMapping* channelSerializationMapping = [channelMapping inverseMapping];
    [RKObjectManager sharedManager].serializationMIMEType = RKMIMETypeJSON;
    //manager.acceptMIMEType = RKMIMETypeJSON; 
    [[RKObjectManager sharedManager].mappingProvider setSerializationMapping:channelSerializationMapping forClass:[Channel class]];