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) 2007: Edouard TISSERANT and Laurent BESSARD
# Copyright (C) 2017: Andrey Skvortsov <andrej.skvortzov@gmail.com>
#
# 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 graphics.GraphicCommons import SELECTION_DIVERGENCE, \
SELECTION_CONVERGENCE, SIMULTANEOUS_DIVERGENCE, SIMULTANEOUS_CONVERGENCE
from graphics.SFC_Objects import SFC_Divergence
from dialogs.BlockPreviewDialog import BlockPreviewDialog
# -------------------------------------------------------------------------------
# Create New Divergence Dialog
# -------------------------------------------------------------------------------
class SFCDivergenceDialog(BlockPreviewDialog):
"""
Class that implements a dialog for defining parameters for creating a new
divergence graphic element
"""
def __init__(self, parent, controller, tagname, poss_div_types=None):
"""
Constructor
@param parent: Parent wx.Window of dialog for modal
@param controller: Reference to project controller
@param tagname: Tagname of project POU edited
@param poss_div_types: Types of divergence that will be available in the dialog window
"""
BlockPreviewDialog.__init__(self, parent, controller, tagname,
title=_('Create a new divergence or convergence'))
# Init common sizers
self._init_sizers(2, 0, 7, None, 2, 1)
# Create label for divergence type
type_label = wx.StaticText(self, label=_('Type:'))
self.LeftGridSizer.AddWindow(type_label, flag=wx.GROW)
# Create radio buttons for selecting divergence type
divergence_buttons = [
(SELECTION_DIVERGENCE, _('Selection Divergence')),
(SELECTION_CONVERGENCE, _('Selection Convergence')),
(SIMULTANEOUS_DIVERGENCE, _('Simultaneous Divergence')),
(SIMULTANEOUS_CONVERGENCE, _('Simultaneous Convergence'))]
poss_div_btns = []
if poss_div_types is not None:
for val in poss_div_types:
poss_div_btns.append(divergence_buttons[val])
else:
poss_div_btns = divergence_buttons
self.TypeRadioButtons = {}
first = True
focusbtn = None
for type, label in poss_div_btns:
radio_button = wx.RadioButton(self, label=label,
style=(wx.RB_GROUP if first else 0))
radio_button.SetValue(first)
self.Bind(wx.EVT_RADIOBUTTON, self.OnTypeChanged, radio_button)
self.LeftGridSizer.AddWindow(radio_button, flag=wx.GROW)
self.TypeRadioButtons[type] = radio_button
if first:
focusbtn = type
first = False
# Create label for number of divergence sequences
sequences_label = wx.StaticText(self,
label=_('Number of sequences:'))
self.LeftGridSizer.AddWindow(sequences_label, flag=wx.GROW)
# Create spin control for defining number of divergence sequences
self.Sequences = wx.SpinCtrl(self, min=2, max=20, initial=2)
self.Bind(wx.EVT_SPINCTRL, self.OnSequencesChanged, self.Sequences)
self.LeftGridSizer.AddWindow(self.Sequences, flag=wx.GROW)
# Add preview panel and associated label to sizers
self.RightGridSizer.AddWindow(self.PreviewLabel, flag=wx.GROW)
self.RightGridSizer.AddWindow(self.Preview, flag=wx.GROW)
# Add buttons sizer to sizers
self.MainSizer.AddSizer(
self.ButtonSizer, border=20,
flag=wx.ALIGN_RIGHT | wx.BOTTOM | wx.LEFT | wx.RIGHT)
self.Fit()
# Selection divergence radio button is default control having keyboard
# focus
self.TypeRadioButtons[focusbtn].SetFocus()
def GetMinElementSize(self):
"""
Get minimal graphic element size
@return: Tuple containing minimal size (width, height) or None if no
element defined
"""
return self.Element.GetMinSize(True)
def GetDivergenceType(self):
"""
Return type selected for SFC divergence
@return: Type selected (None if not found)
"""
# Go through radio buttons and return type associated to the one that
# is selected
for type, control in self.TypeRadioButtons.iteritems():
if control.GetValue():
return type
return None
def GetValues(self):
"""
Set default SFC divergence parameters
@param values: Divergence parameters values
"""
return {"type": self.GetDivergenceType(),
"number": self.Sequences.GetValue()}
def OnTypeChanged(self, event):
"""
Called when SFC divergence type changed
@param event: wx.RadioButtonEvent
"""
self.RefreshPreview()
event.Skip()
def OnSequencesChanged(self, event):
"""
Called when SFC divergence number of sequences changed
@param event: wx.SpinEvent
"""
self.RefreshPreview()
event.Skip()
def RefreshPreview(self):
"""
Refresh preview panel of graphic element
Override BlockPreviewDialog function
"""
# Set graphic element displayed, creating a SFC divergence
self.Element = SFC_Divergence(self.Preview,
self.GetDivergenceType(),
self.Sequences.GetValue())
# Call BlockPreviewDialog function
BlockPreviewDialog.RefreshPreview(self)