beremiz

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

2018-08-24, Andrey Skvortsov
96ca6b056c55
file isExecutable
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) 2016 - 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
from __future__ import print_function
import os
import sys
import getopt
import wx
from wx.lib.agw.advancedsplash import AdvancedSplash, AS_NOTIMEOUT, AS_CENTER_ON_SCREEN
import util.paths as paths
class BeremizIDELauncher(object):
def __init__(self):
self.app = None
self.frame = None
self.updateinfo_url = None
self.extensions = []
self.app_dir = paths.AbsDir(__file__)
self.projectOpen = None
self.buildpath = None
self.splash = None
self.splashPath = self.Bpath("images", "splash.png")
self.modules = ["BeremizIDE"]
self.debug = os.path.exists("BEREMIZ_DEBUG")
self.handle_exception = None
def Bpath(self, *args):
return os.path.join(self.app_dir, *args)
def Usage(self):
print("Usage:")
print("%s [Options] [Projectpath] [Buildpath]" % sys.argv[0])
print("")
print("Supported options:")
print("-h --help Print this help")
print("-u --updatecheck URL Retrieve update information by checking URL")
print("-e --extend PathToExtension Extend IDE functionality by loading at start additional extensions")
print("")
print("")
def SetCmdOptions(self):
self.shortCmdOpts = "hu:e:"
self.longCmdOpts = ["help", "updatecheck=", "extend="]
def ProcessOption(self, o, a):
if o in ("-h", "--help"):
self.Usage()
sys.exit()
if o in ("-u", "--updatecheck"):
self.updateinfo_url = a
if o in ("-e", "--extend"):
self.extensions.append(a)
def ProcessCommandLineArgs(self):
self.SetCmdOptions()
try:
opts, args = getopt.getopt(sys.argv[1:], self.shortCmdOpts, self.longCmdOpts)
except getopt.GetoptError:
# print help information and exit:
self.Usage()
sys.exit(2)
for o, a in opts:
self.ProcessOption(o, a)
if len(args) > 2:
self.Usage()
sys.exit()
elif len(args) == 1:
self.projectOpen = args[0]
self.buildpath = None
elif len(args) == 2:
self.projectOpen = args[0]
self.buildpath = args[1]
def CreateApplication(self):
BeremizAppType = wx.App if wx.VERSION >= (3, 0, 0) else wx.PySimpleApp
class BeremizApp(BeremizAppType):
def OnInit(_self): # pylint: disable=no-self-argument
self.ShowSplashScreen()
return True
self.app = BeremizApp(redirect=self.debug)
self.app.SetAppName('beremiz')
if wx.VERSION < (3, 0, 0):
wx.InitAllImageHandlers()
def ShowSplashScreen(self):
class Splash(AdvancedSplash):
Painted = False
def OnPaint(_self, event): # pylint: disable=no-self-argument
AdvancedSplash.OnPaint(_self, event)
if not _self.Painted: # trigger app start only once
_self.Painted = True
wx.CallAfter(self.AppStart)
bmp = wx.Image(self.splashPath).ConvertToBitmap()
self.splash = Splash(None,
bitmap=bmp,
agwStyle=AS_NOTIMEOUT | AS_CENTER_ON_SCREEN)
def BackgroundInitialization(self):
self.InitI18n()
self.CheckUpdates()
self.LoadExtensions()
self.ImportModules()
def InitI18n(self):
from util.misc import InstallLocalRessources
InstallLocalRessources(self.app_dir)
def globals(self):
"""
allows customizations to specify what globals
are passed to extensions
"""
return globals()
def LoadExtensions(self):
for extfilename in self.extensions:
from util.TranslationCatalogs import AddCatalog
from util.BitmapLibrary import AddBitmapFolder
extension_folder = os.path.split(os.path.realpath(extfilename))[0]
sys.path.append(extension_folder)
AddCatalog(os.path.join(extension_folder, "locale"))
AddBitmapFolder(os.path.join(extension_folder, "images"))
execfile(extfilename, self.globals())
def CheckUpdates(self):
if self.updateinfo_url is not None:
self.updateinfo = _("Fetching %s") % self.updateinfo_url
def updateinfoproc():
try:
import urllib2
self.updateinfo = urllib2.urlopen(self.updateinfo_url, None).read()
except Exception:
self.updateinfo = _("update info unavailable.")
from threading import Thread
self.splash.SetText(text=self.updateinfo)
updateinfoThread = Thread(target=updateinfoproc)
updateinfoThread.start()
updateinfoThread.join(2)
self.splash.SetText(text=self.updateinfo)
def ImportModules(self):
for modname in self.modules:
mod = __import__(modname)
setattr(self, modname, mod)
def InstallExceptionHandler(self):
import version
import util.ExceptionHandler
self.handle_exception = util.ExceptionHandler.AddExceptHook(version.app_version)
def CreateUI(self):
self.frame = self.BeremizIDE.Beremiz(None, self.projectOpen, self.buildpath)
def CloseSplash(self):
if self.splash:
self.splash.Close()
def ShowUI(self):
self.frame.Show()
def PreStart(self):
self.ProcessCommandLineArgs()
self.CreateApplication()
def AppStart(self):
try:
self.BackgroundInitialization()
self.CreateUI()
self.CloseSplash()
self.ShowUI()
except (KeyboardInterrupt, SystemExit):
raise
except Exception:
if self.handle_exception is not None:
self.handle_exception(*sys.exc_info(), exit=True)
else:
raise
def MainLoop(self):
self.app.MainLoop()
def Start(self):
self.PreStart()
self.InstallExceptionHandler()
self.MainLoop()
if __name__ == '__main__':
beremiz = BeremizIDELauncher()
beremiz.Start()