beremiz

Dirty fix for error '_object_has_no_attribute_'getSlave' in EtherCAT extension

2018-08-10, Andrey Skvortsov
a3ac46366b86
Dirty fix for error '_object_has_no_attribute_'getSlave' in EtherCAT extension

traceback:
File "/home/developer/WorkData/PLC/beremiz/beremiz/IDEFrame.py", line 1433, in OnPouSelectedChanged
window.RefreshView()
File "/home/developer/WorkData/PLC/beremiz/beremiz/etherlab/ConfigEditor.py", line 837, in RefreshView
self.RefreshProcessVariables()
File "/home/developer/WorkData/PLC/beremiz/beremiz/etherlab/ConfigEditor.py", line 886, in RefreshProcessVariables
slaves = self.Controler.GetSlaves(**self.CurrentNodesFilter)
File "/home/developer/WorkData/PLC/beremiz/beremiz/etherlab/EthercatMaster.py", line 341, in GetSlaves
for slave in self.Config.getConfig().getSlave():
:_'lxml.etree._Element'_object_has_no_attribute_'getSlave'

Steps to reproduce problem:

- Add new EtherCAT master
- Add new EthercatNode to the master
- double click on


this is looks like dirty hack to fix strange problem with initial[0]
changing its type after returning from _init_ method to lxml.etree._Element
As a result all methods generated by class factory are lost.

For example, in function initMethod initial[0].__class__ points to
xmlclass.xmlclass.Config. After map(self.append, initial)
self.Config.__class__ is 'xmlclass.xmlclass.Config' as well.
But after returning from initMethod (_init) in CreateElement
self.Config.__class__ has changed to lxml.etree._Element.


I've noticed similar behavior if copy/deepcopy is used for any child
of etree.ElementBase. See simple example below.
[-------------------------------------------------------------]
#!/usr/bin/python

from __future__ import print_function
from lxml import etree
import copy

class DefaultElementClass(etree.ElementBase):
def getLocalTag(self):
return etree.QName(self.tag).localname


def printInformation(x):
print(x, x.__class__, "getLocalTag" in dir(x))


a = DefaultElementClass()
printInformation(a)

#
printInformation(copy.copy(a))
printInformation(copy.deepcopy(a))
[-------------------------------------------------------------]
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# This file is part of Beremiz, a Integrated Development Environment for
# programming IEC 61131-3 automates supporting plcopen standard and CanFestival.
#
# Copyright (C) 2012: Edouard TISSERANT and Laurent BESSARD
#
# See COPYING file for copyrights details.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
from __future__ import absolute_import
import wx
from util.BitmapLibrary import GetBitmap
# -------------------------------------------------------------------------------
# Custom button for Graphic Viewer Class
# -------------------------------------------------------------------------------
class GraphButton(object):
"""
Class that implements a custom button for graphic Viewer
"""
def __init__(self, x, y, bitmap, callback):
"""
Constructor
@param x: X coordinate of Button in Graphic Viewer
@param y: Y coordinate of Button in Graphic Viewer
@param bitmap: Name of bitmap to use for button
@param callback: Reference to function to call when button is pressed
"""
# Save button position
self.SetPosition(x, y)
# Set button bitmap
self.SetBitmap(bitmap)
# By default button is hide and enabled
self.Shown = False
self.Enabled = True
# Save reference to callback function
self.Callback = callback
def __del__(self):
"""
Destructor
"""
# Remove reference to callback function
self.callback = None
def SetBitmap(self, bitmap):
"""
Set bitmap to use for button
@param bitmap: Name of bitmap to use for button
"""
# Get wx.Bitmap object corresponding to bitmap
self.Bitmap = GetBitmap(bitmap)
def GetSize(self):
"""
Return size of button
@return: wx.Size object containing button size
"""
# Button size is size of bitmap
return self.Bitmap.GetSize()
def SetPosition(self, x, y):
"""
Set button position
@param x: X coordinate of Button in Graphic Viewer
@param y: Y coordinate of Button in Graphic Viewer
"""
self.Position = wx.Point(x, y)
def Show(self, show=True):
"""
Mark if button to be displayed in Graphic Viewer
@param show: True if button to be displayed in Graphic Viewer
(default True)
"""
self.Shown = show
def Hide(self):
"""
Hide button from Graphic Viewer
"""
self.Show(False)
def IsShown(self):
"""
Return if button is displayed in Graphic Viewer
@return: True if button is displayed in Graphic Viewer
"""
return self.Shown
def Enable(self, enable=True):
"""
Mark if button is active in Graphic Viewer
@param enable: True if button is active in Graphic Viewer
(default True)
"""
self.Enabled = enable
def Disable(self):
"""
Deactivate button in Graphic Viewer
"""
self.Enabled = False
def IsEnabled(self):
"""
Return if button is active in Graphic Viewer
@return: True if button is active in Graphic Viewer
"""
return self.Enabled
def HitTest(self, x, y):
"""
Test if point is inside button
@param x: X coordinate of point
@param y: Y coordinate of point
@return: True if button is active and displayed and point is inside
button
"""
# Return immediately if button is hidden or inactive
if not (self.IsShown() and self.IsEnabled()):
return False
# Test if point is inside button
w, h = self.Bitmap.GetSize()
rect = wx.Rect(self.Position.x, self.Position.y, w, h)
return rect.InsideXY(x, y)
def ProcessCallback(self):
"""
Call callback function if defined
"""
if self.Callback is not None:
self.Callback()
def Draw(self, dc):
"""
Draw button in Graphic Viewer
@param dc: wx.DC object corresponding to Graphic Viewer device context
"""
# Only draw button if button is active and displayed
if self.Shown and self.Enabled:
dc.DrawBitmap(self.Bitmap, self.Position.x, self.Position.y, True)