Ignore nil properties when serializing JSON using RestKit

Question

I have this class:

@interface MovieStatus : NSObject
@property (nonatomic, strong) NSNumber* seen;
@property (nonatomic, strong) NSNumber* watchlist;
@end

Where both properties represent optional nullable boolean values. I'm sending this object to the server using RestKit through the RKObjectManager and created the appropriate mapping. But I'm unable to skip the property from the POST data when serializing the object.

For example, this code:

RKLogConfigureByName("*", RKLogLevelTrace);

RKObjectManager* manager = [RKObjectManager managerWithBaseURL:[NSURL URLWithString:@"http://www.example.com/v1"]];
manager.requestSerializationMIMEType = RKMIMETypeJSON;

RKObjectMapping* requestMapping = [RKObjectMapping requestMapping];
[requestMapping addAttributeMappingsFromArray:@[@"seen", @"watchlist"]];

RKRequestDescriptor* requestDescriptor = [RKRequestDescriptor requestDescriptorWithMapping:requestMapping objectClass:[MovieStatus class] rootKeyPath:nil method:RKRequestMethodPOST];
[manager addRequestDescriptor:requestDescriptor];

RKRoute* route = [RKRoute routeWithClass:[MovieStatus class] pathPattern:@"status" method:RKRequestMethodPOST];
[manager.router.routeSet addRoute:route];


MovieStatus* status = [[MovieStatus alloc] init];
status.seen = @(YES);
[manager postObject:status path:nil parameters:nil success:nil failure:nil];

is sending the JSON:

{
  "seen": true,
  "watchlist": null
}

Where I'd like to send:

{
  "seen": true
}

Can anyone point me out how can I achieve it?

Answer 1

I solved it by setting the assignsDefaultValueForMissingAttributes of the mapping to NO:

requestMapping.assignsDefaultValueForMissingAttributes = NO;

Now the JSON request doesn't contain null values.