From: Andras Zalavari <zalavariandris@...>
Date: 2010-11-15T01:55:55+09:00
Subject: MacRuby KVO array ERROR?

Hi! I'm new To MacRuby, all day I was trying to find what causes the
error in my Code.

I have a 'Scene' class with an attribute 'nodes', which is an array. I
have set up kvo methodes for the array
I have an Observer object, who observes the scene.nodes property. The
observer's options is
'NSKeyValueObservingOptionNew|NSKeyValueObservingOptionOld'

when I add a node to the scene with scene.addNode( new object )
everything is working.
but when I try to remove a node I got an error:

NSInvalidArgumentException: -[NSCFArray countForObject:]: unrecognized
selector sent to instance 0x1b4c210

I only got this error, when I have the NYKeyValueObserbingOptionOld. But
I would really need it.

I assume, the somewhere MacRuby switch the class of the supplied NSSet
containing the objects involved in the change  (in the manual KVO call:
willChangeValueForKey: ... withSetMutation... objects:(NSSet)  )

please help!
Thanks

here is the appropiate code:

OBSERVER.rb

class ConnectionViewController
  attr_accessor:scene,:selection
  attr_accessor:view
  def initialize
    puts 'ConnectionViewController=>initialize'
    NSBundle.loadNibNamed("ConnectionViewController", owner:self)
    addObserver(self,
     forKeyPath:'scene.nodes',
      options:NSKeyValueObservingOptionNew|NSKeyValueObservingOptionOld,
      context:nil)

    node=Node.new
    scene.addNode(node)
    scene.removeNode(node)
  end
  def observeValueForKeyPath(keyPath,
            ofObject:object,
              change:change,
             context:context)
    puts self,' observed:',change,' keyPath:',keyPath
    case change['kind']
      when NSKeyValueChangeInsertion  then
        puts 'insertion: '+change['new'].allObjects.to_s

      when NSKeyValueChangeRemoval then
        puts 'removal: '+change['old'].allObjects.to_s
    end
  end
end

SCENE.m

#import "Scene.h"


@implementation Scene
@synthesize title;
@synthesize nodes,wires;
- (id) init
{
  self = [super init];
  if (self != nil) {
    title=@"untitled scene";
    nodes=[NSMutableArray new];
    wires=[NSMutableArray new];
    NSLog(@"%@=>init",self);
  }
  return self;
}

//PROPERTY METHODES
#pragma mark PROPERTY METHODES
-(Node*)addNode:(Node*)node{
  NSLog(@"Scene->addNode:%@",node);
  NSSet *nodeSet=[NSSet setWithObject:node];
  [self willChangeValueForKey:@"nodes"
withSetMutation:NSKeyValueUnionSetMutation usingObjects:nodeSet];
  [nodes addObject:node];
  node.scene=self;
  [self didChangeValueForKey:@"nodes"
withSetMutation:NSKeyValueUnionSetMutation usingObjects:nodeSet];
  return node;
}
-(void)removeNode:(Node*)node{
  NSSet *nodeSet=[NSSet setWithObjects:node,nil];
  NSLog(@"Scene->removeNode %@",node);
  [self willChangeValueForKey:@"nodes"
withSetMutation:NSKeyValueMinusSetMutation usingObjects:nodeSet];
  [nodes removeObject:node];
  [self didChangeValueForKey:@"nodes"
withSetMutation:NSKeyValueMinusSetMutation usingObjects:nodeSet];
}
@end

Attachments:
http://www.ruby-forum.com/attachment/5372/RubyLine.zip


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