[Pythoncard-users] Trouble with walkthrough 3

[<m.e...@at...>]

In attempting to get through walkthrough 3 I have run into a bit of a wall.  It appears that the on_openBackground methods in the counter module and the child module never execute.  Has the name changed?  Do I need to add code to specifically execute these event methods?  I would appreciate any guidance.  Here is the Counter code:

# Second PythonCard program following walkthrough 3

from PythonCard import model
import child

class Counter(model.Background):
    def on_openBackground(self, event):
        self.childWindow = model.childWindow(self, child.Child)
        # override resource position
        self.childWindow.SetPostion((200,5))
        self.childWindow.Show()
        
    # Counter modification methods
    def incrCtr(self):
        startValue = int(self.components.field1.text)
        endValue = startValue + 1
        self.components.field1.text = str(endValue)
        self.childWindow.components.field1.text = str(endValue)
        
    def decrCtr(self):
        startValue = int(self.components.field1.text)
        endValue = startValue - 1
        self.components.field1.text = str(endValue)
        self.childWindow.components.field1.text = str(endValue)
        
    def rstCtr(self):
        self.components.field1.text = "42"
        
    # Event Handlers
    def on_counterMenuIncr_select(self, event):
        self.incrCtr()
                
    def on_counterMenuDecr_select(self, event):
        self.decrCtr()
        
    def on_counterMenuRst_select(self, event):
        self.rstCtr()
        
    def on_incrBtn_mouseClick(self, event):
        self.incrCtr()
        
    def on_decBtn_mouseClick(self, event):
        self.decrCtr()
        
    def on_rstBtn_mouseClick(self, event):
        self.rstCtr()
        
if __name__ == '__main__':
    app = model.Application(Counter)
    app.MainLoop()

The child module:

"""
__version__ = "$Revision: 1.10 $"
__date__ = "$Date: 2004/04/24 22:13:31 $"
"""

from PythonCard import model

class Child(model.Background):
    
    def on_openBackground(self, event):
        self.parent = self.GetParent()
        
    def on_btnReset_mouseClick(self, event):
        self.parent.components.field1.text = "0"
        
    def doExit(self):
        self.parent.components.field1.text = "99"
        
    def on_close(self, event):
        self.doExit()
        self.Show(0)
        
    def on_menuFileExit_select(self, event):
        self.Close()
        
if __name__ == '__main__':
    app = model.Application(Child)
    app.MainLoop()

When I execute Counter and press the increment button I get the following traceback:

Traceback (most recent call last):
  File "C:\Program Files\Python23\lib\site-packages\PythonCard\widget.py", line
402, in _dispatch
    handler(background, aWxEvent)
  File "C:\Program Files\Python23\Lib\site-packages\PythonCard\samples\myCounter
\myCounter.py", line 44, in on_incrBtn_mouseClick
    self.incrCtr()
  File "C:\Program Files\Python23\Lib\site-packages\PythonCard\samples\myCounter
\myCounter.py", line 22, in incrCtr
    self.childWindow.components.field1.text = str(endValue)
AttributeError: 'Counter' object has no attribute 'childWindow'

It looks like childWindow is not defined because the method that defines it didn't execute.  If it had, i would have expected it to work or traceback on the references to the attribute in that method.  

Mark