beremiz

Proper fix for error 'object has no attribute 'getSlave' in EtherCAT extension

2018-08-24, Andrey Skvortsov
96ca6b056c55
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():
:_'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
#
# 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
import wx.grid
if wx.Platform == '__WXMSW__':
ROW_HEIGHT = 20
else:
ROW_HEIGHT = 28
class CustomTable(wx.grid.PyGridTableBase):
"""
A custom wx.grid.Grid Table using user supplied data
"""
def __init__(self, parent, data, colnames):
# The base class must be initialized *first*
wx.grid.PyGridTableBase.__init__(self)
self.data = data
self.colnames = colnames
self.Highlights = {}
self.Parent = parent
# XXX
# we need to store the row length and collength to
# see if the table has changed size
self._rows = self.GetNumberRows()
self._cols = self.GetNumberCols()
def GetNumberCols(self):
return len(self.colnames)
def GetNumberRows(self):
return len(self.data)
def GetColLabelValue(self, col, translate=True):
if col < len(self.colnames):
if translate:
return _(self.colnames[col])
return self.colnames[col]
def GetRowLabelValue(self, row, translate=True):
return row
def GetValue(self, row, col):
if row < self.GetNumberRows():
return self.data[row].get(self.GetColLabelValue(col, False), "")
def SetValue(self, row, col, value):
if col < len(self.colnames):
self.data[row][self.GetColLabelValue(col, False)] = value
def GetValueByName(self, row, colname):
if row < self.GetNumberRows():
return self.data[row].get(colname)
def SetValueByName(self, row, colname, value):
if row < self.GetNumberRows():
self.data[row][colname] = value
def ResetView(self, grid):
"""
(wx.grid.Grid) -> Reset the grid view. Call this to
update the grid if rows and columns have been added or deleted
"""
grid.CloseEditControl()
grid.BeginBatch()
for current, new, delmsg, addmsg in [
(
self._rows,
self.GetNumberRows(),
wx.grid.GRIDTABLE_NOTIFY_ROWS_DELETED,
wx.grid.GRIDTABLE_NOTIFY_ROWS_APPENDED
),
(
self._cols,
self.GetNumberCols(),
wx.grid.GRIDTABLE_NOTIFY_COLS_DELETED,
wx.grid.GRIDTABLE_NOTIFY_COLS_APPENDED
),
]:
if new < current:
msg = wx.grid.GridTableMessage(self, delmsg, new, current-new)
grid.ProcessTableMessage(msg)
elif new > current:
msg = wx.grid.GridTableMessage(self, addmsg, new-current)
grid.ProcessTableMessage(msg)
self.UpdateValues(grid)
grid.EndBatch()
self._rows = self.GetNumberRows()
self._cols = self.GetNumberCols()
# update the column rendering scheme
self._updateColAttrs(grid)
# update the scrollbars and the displayed part of the grid
grid.AdjustScrollbars()
grid.ForceRefresh()
def UpdateValues(self, grid):
"""Update all displayed values"""
# This sends an event to the grid table to update all of the values
msg = wx.grid.GridTableMessage(self, wx.grid.GRIDTABLE_REQUEST_VIEW_GET_VALUES)
grid.ProcessTableMessage(msg)
def _updateColAttrs(self, grid):
"""
wx.grid.Grid -> update the column attributes to add the
appropriate renderer given the column name.
Otherwise default to the default renderer.
"""
for row in range(self.GetNumberRows()):
row_highlights = self.Highlights.get(row, {})
for col in range(self.GetNumberCols()):
colname = self.GetColLabelValue(col, False)
grid.SetReadOnly(row, col, True)
grid.SetCellEditor(row, col, None)
grid.SetCellRenderer(row, col, None)
highlight_colours = row_highlights.get(colname.lower(), [(wx.WHITE, wx.BLACK)])[-1]
grid.SetCellBackgroundColour(row, col, highlight_colours[0])
grid.SetCellTextColour(row, col, highlight_colours[1])
self.ResizeRow(grid, row)
def ResizeRow(self, grid, row):
if grid.GetRowSize(row) < ROW_HEIGHT:
grid.SetRowMinimalHeight(row, ROW_HEIGHT)
grid.AutoSizeRow(row, False)
def SetData(self, data):
self.data = data
def GetData(self):
return self.data
def GetCurrentIndex(self):
return self.CurrentIndex
def SetCurrentIndex(self, index):
self.CurrentIndex = index
def AppendRow(self, row_content):
self.data.append(row_content)
def InsertRow(self, index, row_content):
self.data.insert(index, row_content)
def MoveRow(self, row_index, move):
new_index = max(0, min(row_index + move, len(self.data) - 1))
if new_index != row_index:
self.data.insert(new_index, self.data.pop(row_index))
return new_index
def RemoveRow(self, row_index):
self.data.pop(row_index)
def GetRow(self, row_index):
return self.data[row_index]
def Empty(self):
self.data = []
def AddHighlight(self, infos, highlight_type):
row_highlights = self.Highlights.setdefault(infos[0], {})
col_highlights = row_highlights.setdefault(infos[1], [])
col_highlights.append(highlight_type)
def RemoveHighlight(self, infos, highlight_type):
row_highlights = self.Highlights.get(infos[0])
if row_highlights is not None:
col_highlights = row_highlights.get(infos[1])
if col_highlights is not None and highlight_type in col_highlights:
col_highlights.remove(highlight_type)
if len(col_highlights) == 0:
row_highlights.pop(infos[1])
def ClearHighlights(self, highlight_type=None):
if highlight_type is None:
self.Highlights = {}
else:
for _row, row_highlights in self.Highlights.iteritems():
row_items = row_highlights.items()
for col, col_highlights in row_items:
if highlight_type in col_highlights:
col_highlights.remove(highlight_type)
if len(col_highlights) == 0:
row_highlights.pop(col)