No Quotes in JSON for ManagedObject? - json

Question

In reading the documentation and sample code for posting objects, I must have missed something relating to serializing entities. It appears possible to send an entity to postObject and expect it to use the supplied mapping to produce JSON and POST it to a server.
I have been able to map and post an object, but the JSON is not coming through well formed.
I have been able to hand parameterize the object and get valid JSON. I'm about to dig into the source-code, but was wondering what I'm missing.
Here's the code and the results I'm seeing. Insight/help is appreciated!
I have the following Managed Object:
#interface TFUser : NSManagedObject
#property (nonatomic, retain) NSString * first_name;
#property (nonatomic, retain) NSString * last_name;
#end
I have the following code to map it:
+(RKEntityMapping *) mapping
{
if (_mapping == nil)
{
RKObjectManager *objectManager = [RKObjectManager sharedManager];
assert(objectManager && "Object manager not initialized!?");
RKManagedObjectStore *managedObjectStore = objectManager.managedObjectStore;
assert(objectManager && "No object store!?");
// USER Entity Map
_mapping = [RKEntityMapping mappingForEntityForName:#"TFUser"
inManagedObjectStore:managedObjectStore];
[_mapping addAttributeMappingsFromDictionary:#{
#"first_name": #"first_name",
#"last_name": #"last_name"
}];
_mapping.identificationAttributes = #[ #"first_name" ];
}
return _mapping;
}
I have the following code to test serializing one Managed Object directly:
TFUser *user = (TFUser*) [self.managedObjectContext insertNewObjectForEntityForName:#"TFUser"];
user.first_name = #"Mickey";
user.last_name = #"Mouse";
NSError *error;
RKRequestDescriptor *requestDescriptor =
[RKRequestDescriptor requestDescriptorWithMapping:[TFUser.mapping inverseMapping]
objectClass:[TFUser class]
rootKeyPath:#"user"
method:RKRequestMethodAny];
NSDictionary *parameters = [RKObjectParameterization parametersWithObject:user
requestDescriptor:requestDescriptor
error:&error];
NSData *jsonData= [RKMIMETypeSerialization dataFromObject:parameters MIMEType:RKMIMETypeJSON error:&error];
NSString *message = [[NSString alloc] initWithData:jsonData encoding:NSASCIIStringEncoding];
NSLog(#"USER JSON:\r\n%#", message);
And this produces what I'd expect:
USER JSON:
{
"user" : {
"first_name" : "Mickey",
"last_name" : "Mouse"
}
}
When I postObject the Managed Object directly:
[[RKObjectManager sharedManager] postObject:user
path:#"/user"
parameters:nil
success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
NSLog(#"Success");
}
failure:^(RKObjectRequestOperation *operation, NSError *error) {
NSLog(#"Error");
}];
The server receives:
{ user: { first_name: 'Mickey', last_name: 'Mouse' } }
And the parser complains that it can't process the JSON.
Why am I getting a different result? How can I get the post to produce the correct JSON for the server?
Thanks!
- Kevin

Answer 1

The code has been working the entire time. The debugging and some code on the server was broken.
By carefully inspecting the logging of the body request being sent to the server it was apparent that the JSON was well-formed leaving the client. Here it is:
request.headers={
Accept = "application/json";
"Accept-Language" = "en;q=1, fr;q=0.9, de;q=0.8, zh-Hans;q=0.7, zh-Hant;q=0.6, ja;q=0.5";
"Content-Type" = "application/json; charset=utf-8";
"User-Agent" = "Treefort/1.0 (iPhone Simulator; iOS 7.0.3; Scale/2.00)";
}
request.body={
"user" : {
"first_name" : "Mickey",
"last_name" : "Mouse"
}
}
The code on the server was doing this:
console.log req.body
request = JSON.parse req.body
user = request.user
The JSON has already been processed into objects by the time it gets here. This means that the log line is dumping the object to the log, not the text of the received body. The second problem is that there is no reason to be explicitly requesting a JSON parse of the body. It's already been converted to objects.
To fix it I just changed the code to be:
user = req.body.user
Sometimes it helps to have somebody else say... it should be working. I've been banging my head on this for days. Thanks!