dialogs/SFCDivergenceDialog.py
author Andrey Skvortsov <andrej.skvortzov@gmail.com>
Fri, 24 Aug 2018 13:41:43 +0300
changeset 2297 96ca6b056c55
parent 1853 47a3f39bead0
child 2587 c67488bd8134
permissions -rw-r--r--
Proper 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():
<type 'exceptions.AttributeError'>:_'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


Revert commit "Dirty fix for error '_object_has_no_attribute_'getSlave' in EtherCAT extension"
[a3ac46366b86a0b237dac93be6b2281ac70b98a8].

The problem was that XML elements (proxy object) in some cases were created using custom XML
classes constructors and lxml.etree.Element() call and live python
patching. This causes that lxml backend doesn't know that custom python class
should be used for these XML elements.
Proxy object can be move/deleted and recreated by lxml
backend at any point in time or this can be done in python by copy/deepcopy operations.
If this happens, then newly created
proxy elements are using default class lxml.etree._Element. And all
custom functionality is lost.

All created XML elements should be always created through corresponding
parser and class lookup callback done by lxml backend.
It's described in more details in lxml documentation:
https://lxml.de/element_classes.html
#!/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)