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
#
# 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 os
from nevow import tags, loaders
import simplejson as json # pylint: disable=import-error
import runtime.NevowServer as NS
svgfile = '%(svgfile)s'
svguiWidgets = {}
currentId = 0
def getNewId():
global currentId
currentId += 1
return currentId
class SvguiWidget(object):
def __init__(self, classname, id, **kwargs):
self.classname = classname
self.id = id
self.attrs = kwargs.copy()
self.inputs = {}
self.outputs = {}
self.inhibit = False
self.changed = False
def setinput(self, attrname, value):
self.inputs[attrname] = value
def getinput(self, attrname, default=None):
if attrname not in self.inputs:
self.inputs[attrname] = default
return self.inputs[attrname]
def setoutput(self, attrname, value):
if self.outputs.get(attrname) != value:
self.outputs[attrname] = value
self.changed = True
self.RefreshInterface()
def updateoutputs(self, **kwargs):
for attrname, value in kwargs.iteritems():
if self.outputs.get(attrname) != value:
self.outputs[attrname] = value
self.changed = True
self.RefreshInterface()
def RefreshInterface(self):
interface = website.getHMI()
if isinstance(interface, SVGUI_HMI) and self.changed and not self.inhibit:
self.changed = False
d = interface.sendData(self)
if d is not None:
self.inhibit = True
d.addCallback(self.InterfaceRefreshed)
def InterfaceRefreshed(self, result):
self.inhibit = False
if self.changed:
self.RefreshInterface()
def get_object_init_state(obj):
# Convert objects to a dictionary of their representation
attrs = obj.attrs.copy()
attrs.update(obj.inputs)
d = {
'__class__': obj.classname,
'id': obj.id,
'kwargs': json.dumps(attrs),
}
return d
def get_object_current_state(obj):
# Convert objects to a dictionary of their representation
d = {
'__class__': obj.classname,
'id': obj.id,
'kwargs': json.dumps(obj.outputs),
}
return d
class SVGUI_HMI(website.PLCHMI):
jsClass = u"LiveSVGPage.LiveSVGWidget"
docFactory = loaders.stan(tags.div(render=tags.directive('liveElement'))[
tags.xml(loaders.xmlfile(os.path.join(NS.WorkingDir, svgfile))),
])
def HMIinitialisation(self):
gadgets = []
for gadget in svguiWidgets.values():
gadgets.append(unicode(json.dumps(gadget, default=get_object_init_state, indent=2), 'ascii'))
d = self.callRemote('init', gadgets)
d.addCallback(self.HMIinitialised)
def sendData(self, data):
if self.initialised:
return self.callRemote('receiveData', unicode(json.dumps(data, default=get_object_current_state, indent=2), 'ascii'))
return None
def setattr(self, id, attrname, value):
svguiWidgets[id].setinput(attrname, value)
def createSVGUIControl(*args, **kwargs):
id = getNewId()
gad = SvguiWidget(args[0], id, **kwargs)
svguiWidgets[id] = gad
gadget = [unicode(json.dumps(gad, default=get_object_init_state, indent=2), 'ascii')]
interface = website.getHMI()
if isinstance(interface, SVGUI_HMI) and interface.initialised:
interface.callRemote('init', gadget)
return id
def setAttr(id, attrname, value):
gad = svguiWidgets.get(id, None)
if gad is not None:
gad.setoutput(attrname, value)
def updateAttr(id, **kwargs):
gad = svguiWidgets.get(id, None)
if gad is not None:
gad.updateoutput(**kwargs)
def getAttr(id, attrname, default=None):
gad = svguiWidgets.get(id, None)
if gad is not None:
return gad.getinput(attrname, default)
return default