plcopen/POUVariablesCollector.py
author Andrey Skvortsov <andrej.skvortzov@gmail.com>
Fri, 10 Aug 2018 17:45:33 +0300
changeset 2278 a3ac46366b86
parent 1973 cc7a46953471
child 3750 f62625418bff
permissions -rw-r--r--
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():
<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


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.
# See COPYING file for copyrights details.

from __future__ import absolute_import
from plcopen.XSLTModelQuery import XSLTModelQuery, _StringValue, _BoolValue, _translate_args
from plcopen.types_enums import CLASS_TYPES, POU_TYPES, VAR_CLASS_INFOS


def class_extraction(value):
    class_type = CLASS_TYPES.get(value)
    if class_type is not None:
        return class_type

    pou_type = POU_TYPES.get(value)
    if pou_type is not None:
        return pou_type

    var_type = VAR_CLASS_INFOS.get(value)
    if var_type is not None:
        return var_type[1]

    return None


class _VariablesTreeItemInfos(object):
    __slots__ = ["name", "var_class", "type", "edit", "debug", "variables"]

    def __init__(self, *args):
        for attr, value in zip(self.__slots__, args):
            setattr(self, attr, value if value is not None else "")

    def copy(self):
        return _VariablesTreeItemInfos(*[getattr(self, attr) for attr in self.__slots__])


class VariablesTreeInfosFactory(object):

    def __init__(self):
        self.Root = None

    def GetRoot(self):
        return self.Root

    def SetRoot(self, context, *args):
        self.Root = _VariablesTreeItemInfos(
            *([''] + _translate_args(
                [class_extraction, _StringValue] + [_BoolValue] * 2,
                args) + [[]]))

    def AddVariable(self, context, *args):
        if self.Root is not None:
            self.Root.variables.append(_VariablesTreeItemInfos(
                *(_translate_args(
                    [_StringValue, class_extraction, _StringValue] +
                    [_BoolValue] * 2, args) + [[]])))


class POUVariablesCollector(XSLTModelQuery):
    def __init__(self, controller):
        XSLTModelQuery.__init__(self,
                                controller,
                                "pou_variables.xslt",
                                [(name, self.FactoryCaller(name))
                                 for name in ["SetRoot", "AddVariable"]])

    def FactoryCaller(self, funcname):
        def CallFactory(*args):
            return getattr(self.factory, funcname)(*args)
        return CallFactory

    def Collect(self, root, debug):
        self.factory = VariablesTreeInfosFactory()
        self._process_xslt(root, debug)
        res = self.factory.GetRoot()
        self.factory = None
        return res