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 -*-
# Copyright (C) 2018: Smarteh
#
# See COPYING file for copyrights details.
from __future__ import absolute_import
from __future__ import print_function
import wx
from zope.interface import implementer
from controls.UriLocationEditor import IConnectorPanel
URITypes = ["LOCAL", "PYRO", "PYROS"]
def PYRO_connector_dialog(confnodesroot):
[ID_IPTEXT, ID_PORTTEXT] = [wx.NewId() for _init_ctrls in range(2)]
@implementer(IConnectorPanel)
class PYROConnectorPanel(wx.Panel):
def __init__(self, typeConnector, parrent, *args, **kwargs):
self.type = typeConnector
self.parrent = parrent
wx.Panel.__init__(self, parrent, *args, **kwargs)
self._init_ctrls()
self._init_sizers()
self.uri = None
def _init_ctrls(self):
self.IpText = wx.TextCtrl(parent=self, id=ID_IPTEXT, size=wx.Size(200, -1))
self.PortText = wx.TextCtrl(parent=self, id=ID_PORTTEXT, size=wx.Size(200, -1))
def _init_sizers(self):
self.mainSizer = wx.FlexGridSizer(cols=2, hgap=10, rows=5, vgap=10)
self.mainSizer.AddWindow(wx.StaticText(self, label=_("URI host:")),
flag=wx.ALIGN_CENTER_VERTICAL)
self.mainSizer.AddWindow(self.IpText, flag=wx.GROW)
self.mainSizer.AddWindow(wx.StaticText(self, label=_("URI port:")),
flag=wx.ALIGN_CENTER_VERTICAL)
self.mainSizer.AddWindow(self.PortText, flag=wx.GROW)
self.SetSizer(self.mainSizer)
def SetURI(self, uri):
self.uri = uri
uri_list = uri.strip().split(":")
length = len(uri_list)
if length == 3:
self.IpText.SetValue(uri_list[1].strip("/"))
self.PortText.SetValue(uri_list[2])
elif length == 2:
self.IpText.SetValue(uri_list[1].strip("/"))
def GetURI(self):
self.uri = self.type+"://"+self.IpText.GetValue()+":"+self.PortText.GetValue()
return self.uri
return PYROConnectorPanel("PYRO", confnodesroot)