[Jython-users] jython, recursion and XML

[Ted B. <te...@et...>]

I'm trying to build a simple XML editor targetted at a specific use.  I am 
displaying the xml node names as elements in a JTree and have implemented a 
TreeModel to accomplish this.

The nodes in the tree model extract relevant info from a JDOM Element object 
passed to their fromXML method after creation.  This method populates the 
callee node's child list and calls each child's fromXML method.

From the print out generated by the fromXML method, it appears that 
everything is working, but when the process is complete another print shows 
that something has gone dramatically wrong.

print generated during population:

 [Element: <nodehandler/>]
  [Element: <group_atts/>]
  [Element: <nodehandler/>]
   [Element: <file/>]
  [Element: <nodehandler/>]
   [Element: <file/>]
  [Element: <nodehandler/>]
   [Element: <file/>]

print of tree root element's 'children' list after population of the 
TreeModel:

[group_atts, file, nodehandler, file, nodehandler, file, nodehandler]

Relevant code snippet from InstallSetTreeModel:

  def fromXML( self, node, space='' ):
    print space,node
    self.name = node.name
    for n in node.children:
      f = InstallSetTreeModel( self )
      f.fromXML( n, space+' ')
      self.children.append( f )

Obviously *something* isn't right.  What am I doing wrong?  node is a JDOM 
Element object, node.children returns a List of child Elements.  Once this 
model is placed in a tree, each node in the tree has for children each node 
in the tree.  It's a *huge* circular reference bug, and I haven't been able 
to find it.

The code is part of a project that will allow java/jython applications to 
download updates from a website.  The whole shebang will be publicly 
available when i'm done too, if that's any sort of carrot. :)

I can post the whole file if it would help, I just wanted to avoid spamming 
the list right off.

ted