Should Gaffer.ScriptNode().applicationRoot() ever == None ??

[bentoogood]

Hi - in context of writing a gaffer app, once a Gaffer.ScriptNode is instantiated, should it not have a valid applicationRoot ?

In this example scriptNode.applicationRoot() returns None, causing the isinstance check to return False:

import Gaffer, IECore

class appRootDebug( Gaffer.Application ) :
    def __init__( self ) :

        Gaffer.Application.__init__( self, "Simple UI" )

    def _run( self, args ) :

        import GafferUI
        import GafferSceneUI

        scriptNode = Gaffer.ScriptNode()

        print scriptNode.applicationRoot()
        print isinstance( self, Gaffer.Application )
        print isinstance( scriptNode.applicationRoot(), Gaffer.Application )

        GafferUI.EventLoop.mainEventLoop().start()
        return 0

IECore.registerRunTimeTyped( appRootDebug )

This appears to be causing trouble in a more complex example. In an app with a NodeGraph editor, right click raises this error:

Traceback (most recent call last):
  File ".../python/GafferUI/Widget.py", line 1550, in eventFilter
    return self.__mouseButtonPress( qObject, qEvent )
  File ".../python/GafferUI/Widget.py", line 1643, in __mouseButtonPress
    result = widget._buttonPressSignal( widget, event )
  File ".../python/Gaffer/WeakMethod.py", line 57, in __call__
    return m( *args, **kwArgs )
  File ".../python/GafferUI/NodeGraph.py", line 264, in __buttonPress
    self._nodeMenu().popup( self )
  File ".../python/GafferUI/NodeGraph.py", line 225, in _nodeMenu
    self.__nodeMenu = GafferUI.Menu( GafferUI.NodeMenu.acquire( self.scriptNode().applicationRoot() ).definition(), searchable=True )
  File ".../python/GafferUI/NodeMenu.py", line 68, in acquire
    assert( isinstance( applicationOrApplicationRoot, Gaffer.ApplicationRoot ) )
AssertionError

The call to looks like line 225 in NodeGraph.py is passing None through as the applicationOrApplicationRoot causing the assert error.

thoughts?

[johnhaddon]

It's the responsibility of the app to add the ScriptNode to the scripts container in the ApplicationRoot - see the gui app for example :

self.root()["scripts"].addChild( scriptNode )