CodeFileTreeNode.py
author Andrey Skvortsov <andrej.skvortzov@gmail.com>
Fri, 24 Aug 2018 13:41:43 +0300
changeset 2297 96ca6b056c55
parent 1969 0607c382d73f
child 2418 5587c490a070
permissions -rw-r--r--
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():
<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


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 os
import re
import traceback

from copy import deepcopy
from lxml import etree
from xmlclass import GenerateParserFromXSDstring

from PLCControler import UndoBuffer
from ConfigTreeNode import XSDSchemaErrorMessage

CODEFILE_XSD = """<?xml version="1.0" encoding="ISO-8859-1" ?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
            xmlns:xhtml="http://www.w3.org/1999/xhtml">
  <xsd:element name="%(codefile_name)s">
    <xsd:complexType>
      <xsd:sequence>
        %(includes_section)s
        <xsd:element name="variables">
          <xsd:complexType>
            <xsd:sequence>
              <xsd:element name="variable" minOccurs="0" maxOccurs="unbounded">
                <xsd:complexType>
                  <xsd:attribute name="name" type="xsd:string" use="required"/>
                  <xsd:attribute name="type" type="xsd:string" use="required"/>
                  <xsd:attribute name="class" use="optional">
                    <xsd:simpleType>
                      <xsd:restriction base="xsd:string">
                        <xsd:enumeration value="input"/>
                        <xsd:enumeration value="memory"/>
                        <xsd:enumeration value="output"/>
                      </xsd:restriction>
                    </xsd:simpleType>
                  </xsd:attribute>
                  <xsd:attribute name="initial" type="xsd:string" use="optional" default=""/>
                  <xsd:attribute name="desc" type="xsd:string" use="optional" default=""/>
                  <xsd:attribute name="onchange" type="xsd:string" use="optional" default=""/>
                  <xsd:attribute name="opts" type="xsd:string" use="optional" default=""/>
                </xsd:complexType>
              </xsd:element>
            </xsd:sequence>
          </xsd:complexType>
        </xsd:element>
        %(sections)s
      </xsd:sequence>
    </xsd:complexType>
  </xsd:element>
  <xsd:complexType name="CodeText">
    <xsd:annotation>
      <xsd:documentation>Formatted text according to parts of XHTML 1.1</xsd:documentation>
    </xsd:annotation>
    <xsd:sequence>
      <xsd:any namespace="http://www.w3.org/1999/xhtml" processContents="lax"/>
    </xsd:sequence>
  </xsd:complexType>
</xsd:schema>"""

SECTION_TAG_ELEMENT = "<xsd:element name=\"%s\" type=\"CodeText\"/>"


class CodeFile(object):

    CODEFILE_NAME = "CodeFile"
    SECTIONS_NAMES = []

    def __init__(self):
        sections_str = {"codefile_name": self.CODEFILE_NAME}
        if "includes" in self.SECTIONS_NAMES:
            sections_str["includes_section"] = SECTION_TAG_ELEMENT % "includes"
        else:
            sections_str["includes_section"] = ""
        sections_str["sections"] = "\n".join(
            [SECTION_TAG_ELEMENT % name
             for name in self.SECTIONS_NAMES if name != "includes"])

        self.CodeFileParser = GenerateParserFromXSDstring(
            CODEFILE_XSD % sections_str)
        self.CodeFileVariables = etree.XPath("variables/variable")

        filepath = self.CodeFileName()
        if os.path.isfile(filepath):
            xmlfile = open(filepath, 'r')
            codefile_xml = xmlfile.read()
            xmlfile.close()

            codefile_xml = codefile_xml.replace(
                '<%s>' % self.CODEFILE_NAME,
                '<%s xmlns:xhtml="http://www.w3.org/1999/xhtml">' % self.CODEFILE_NAME)
            for cre, repl in [
                    (re.compile("(?<!<xhtml:p>)(?:<!\[CDATA\[)"), "<xhtml:p><![CDATA["),
                    (re.compile("(?:]]>)(?!</xhtml:p>)"), "]]></xhtml:p>")]:
                codefile_xml = cre.sub(repl, codefile_xml)

            try:
                self.CodeFile, error = self.CodeFileParser.LoadXMLString(codefile_xml)
                if error is not None:
                    (fname, lnum, src) = ((self.CODEFILE_NAME,) + error)
                    self.GetCTRoot().logger.write_warning(XSDSchemaErrorMessage.format(a1=fname, a2=lnum, a3=src))
                self.CreateCodeFileBuffer(True)
            except Exception, exc:
                msg = _("Couldn't load confnode parameters {a1} :\n {a2}").format(a1=self.CTNName(), a2=unicode(exc))
                self.GetCTRoot().logger.write_error(msg)
                self.GetCTRoot().logger.write_error(traceback.format_exc())
                raise Exception
        else:
            self.CodeFile = self.CodeFileParser.CreateRoot()
            self.CreateCodeFileBuffer(False)
            self.OnCTNSave()

    def GetBaseTypes(self):
        return self.GetCTRoot().GetBaseTypes()

    def GetDataTypes(self, basetypes=False):
        return self.GetCTRoot().GetDataTypes(basetypes=basetypes)

    def GenerateNewName(self, name, format):
        return self.GetCTRoot().GenerateNewName(
            None, name, format,
            exclude=dict([(var.getname().upper(), True)
                          for var in self.CodeFile.variables.getvariable()]))

    def SetVariables(self, variables):
        self.CodeFile.variables.setvariable([])
        for var in variables:
            variable = self.CodeFileParser.CreateElement("variable", "variables")
            variable.setname(var["Name"])
            variable.settype(var["Type"])
            variable.setinitial(var["Initial"])
            variable.setdesc(var["Description"])
            variable.setonchange(var["OnChange"])
            variable.setopts(var["Options"])
            self.CodeFile.variables.appendvariable(variable)

    def GetVariables(self):
        datas = []
        for var in self.CodeFileVariables(self.CodeFile):
            datas.append({
                "Name":        var.getname(),
                "Type":        var.gettype(),
                "Initial":     var.getinitial(),
                "Description": var.getdesc(),
                "OnChange":    var.getonchange(),
                "Options":     var.getopts(),
            })
        return datas

    def SetTextParts(self, parts):
        for section in self.SECTIONS_NAMES:
            section_code = parts.get(section)
            if section_code is not None:
                getattr(self.CodeFile, section).setanyText(section_code)

    def GetTextParts(self):
        return dict([(section, getattr(self.CodeFile, section).getanyText())
                     for section in self.SECTIONS_NAMES])

    def CTNTestModified(self):
        return self.ChangesToSave or not self.CodeFileIsSaved()

    def OnCTNSave(self, from_project_path=None):
        filepath = self.CodeFileName()

        xmlfile = open(filepath, "w")
        xmlfile.write(etree.tostring(
            self.CodeFile,
            pretty_print=True,
            xml_declaration=True,
            encoding='utf-8'))
        xmlfile.close()

        self.MarkCodeFileAsSaved()
        return True

    def CTNGlobalInstances(self):
        variables = self.CodeFileVariables(self.CodeFile)
        ret = [(variable.getname(),
                variable.gettype(),
                variable.getinitial())
               for variable in variables]
        ret.extend([("On"+variable.getname()+"Change", "python_poll", "")
                    for variable in variables
                    if variable.getonchange()])
        return ret

# -------------------------------------------------------------------------------
#                      Current Buffering Management Functions
# -------------------------------------------------------------------------------

    def Copy(self, model):
        """
        Return a copy of the codefile model
        """
        return deepcopy(model)

    def CreateCodeFileBuffer(self, saved):
        self.Buffering = False
        self.CodeFileBuffer = UndoBuffer(self.CodeFileParser.Dumps(self.CodeFile), saved)

    def BufferCodeFile(self):
        self.CodeFileBuffer.Buffering(self.CodeFileParser.Dumps(self.CodeFile))

    def StartBuffering(self):
        self.Buffering = True

    def EndBuffering(self):
        if self.Buffering:
            self.CodeFileBuffer.Buffering(self.CodeFileParser.Dumps(self.CodeFile))
            self.Buffering = False

    def MarkCodeFileAsSaved(self):
        self.EndBuffering()
        self.CodeFileBuffer.CurrentSaved()

    def CodeFileIsSaved(self):
        return self.CodeFileBuffer.IsCurrentSaved() and not self.Buffering

    def LoadPrevious(self):
        self.EndBuffering()
        self.CodeFile = self.CodeFileParser.Loads(self.CodeFileBuffer.Previous())

    def LoadNext(self):
        self.CodeFile = self.CodeFileParser.Loads(self.CodeFileBuffer.Next())

    def GetBufferState(self):
        first = self.CodeFileBuffer.IsFirst() and not self.Buffering
        last = self.CodeFileBuffer.IsLast()
        return not first, not last