First mapping

InitRestKit.m

- (void)mapObjects:(RKObjectManager*)objectManager
{
  RKObjectMapping* widgetMapping = [RKObjectMapping mappingForClass:[widget class]];
  [widgetMapping mapKeyPath:@"id" toAttribute:@"widgetID"];
  [widgetMapping mapAttributes:@"name", @"description", nil];
  [widgetMapping mapKeyPath:@"public" toAttribute:@"isPublic"];
  [widgetMapping mapKeyPath:@"created_at" toAttribute:@"createdAt"];
  [widgetMapping mapKeyPath:@"updated_at" toAttribute:@"updatedAt"];
  [objectManager.mappingProvider setMapping:widgetMapping forKeyPath:@"widget"];
}

- (void)initRestKit
{
  // Configure parser based on what is being linked
  [[RKParserRegistry sharedRegistry] autoconfigure];
  
  NSString* baseURL = [self baseURL];
  
  // Create a client.
  [RKClient setSharedClient:[[RKClient alloc] initWithBaseURL:baseURL]];
  
  // first object manager becomes the shared instance
  RKObjectManager* objectManager = [RKObjectManager objectManagerWithBaseURL:baseURL];
  [objectManager setClient:[RKClient sharedClient]];
  
  // custom configuration of the RKClient... magic headers, etc.
  // ...

  // This is probably redundant but it makes be feel better doing it explicitly.
  [RKObjectManager setSharedManager:objectManager];
  
  // map the widget object
  [self mapObjects:objectManager];
}

response.json

// The response coming from the remote server 

[{"commented_at":null,"created_at":"2011-08-04T15:35:03Z","description":"Other","id":7,"name":"Misc Widget","type_index":0,"updated_at":"2011-08-04T15:35:03Z","user_id":5},{"commented_at":null,"created_at":"2011-08-04T15:35:03Z","description":"Cool","id":6,"name":"Coolness Widget","type_index":1,"updated_at":"2011-08-04T15:35:03Z","user_id":5},{"commented_at":null,"created_at":"2011-08-04T15:35:02Z","description":"Awesome Widget","id":5,,"name":"Another Widget","type_index":0,"updated_at":"2011-08-04T15:35:03Z","user_id":5}]

WidgetTableViewController.m

// In the view controller

  [[RKObjectManager sharedManager] loadObjectsAtResourcePath:@"widgets.json" delegate:self];

// delegate method shoves stuff into the table view

Xcode output

# The error


 W restkit.object_mapping:RKObjectMapper.m:90 Found a collection containing only NSNull values, considering the collection unmappable...
 W restkit.object_mapping:RKObjectMapper.m:90 Found a collection containing only NSNull values, considering the collection unmappable...
 W restkit.object_mapping:RKObjectMapper.m:90 Found a collection containing only NSNull values, considering the collection unmappable...
 W restkit.object_mapping:RKObjectMapper.m:60 Adding mapping error: Could not find an object mapping for keyPath: ''
 E restkit.network:RKObjectLoader.m:178 Encountered errors during mapping: Could not find an object mapping for keyPath: ''
 Widget Load Failed: Could not find an object mapping for keyPath: ''

dt notes: your json response should look like {"widget":[..]}

dt suggests a mod to line 9
[objectManager.mappingProvider setMapping:widgetMapping forKeyPath:@""];

I tried this but I still get 2 W messages. (And my table doesn't appear to be populating.)