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))
[-------------------------------------------------------------]
<?xml version="1.0"?>
<xsl:stylesheet xmlns:exsl="http://exslt.org/common" xmlns:xhtml="http://www.w3.org/1999/xhtml" xmlns:ppx="http://www.plcopen.org/xml/tc6_0201" xmlns:ns="beremiz" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" extension-element-prefixes="ns" version="1.0" exclude-result-prefixes="ns">
<xsl:output method="xml"/>
<xsl:param name="instance_type"/>
<xsl:template match="text()"/>
<xsl:variable name="project" select="ns:GetProject()"/>
<xsl:variable name="stdlib" select="ns:GetStdLibs()"/>
<xsl:variable name="extensions" select="ns:GetExtensions()"/>
<xsl:variable name="all_types" select="($project | $stdlib | $extensions)/ppx:types"/>
<xsl:template match="ppx:project">
<xsl:apply-templates select="ppx:instances/ppx:configurations/ppx:configuration"/>
</xsl:template>
<xsl:template match="ppx:configuration">
<xsl:apply-templates select="ppx:globalVars/ppx:variable[ppx:type/ppx:derived] | ppx:resource">
<xsl:with-param name="parent_path">
<xsl:value-of select="@name"/>
</xsl:with-param>
</xsl:apply-templates>
</xsl:template>
<xsl:template match="ppx:resource">
<xsl:param name="parent_path"/>
<xsl:variable name="resource_path">
<xsl:value-of select="$parent_path"/>
<xsl:text>.</xsl:text>
<xsl:value-of select="@name"/>
</xsl:variable>
<xsl:apply-templates select="ppx:globalVars/ppx:variable[ppx:type/ppx:derived] | ppx:pouInstance | ppx:task/ppx:pouInstance">
<xsl:with-param name="parent_path">
<xsl:value-of select="$resource_path"/>
</xsl:with-param>
</xsl:apply-templates>
</xsl:template>
<xsl:template match="ppx:pouInstance">
<xsl:param name="parent_path"/>
<xsl:variable name="pou_instance_path">
<xsl:value-of select="$parent_path"/>
<xsl:text>.</xsl:text>
<xsl:value-of select="@name"/>
</xsl:variable>
<xsl:choose>
<xsl:when test="@typeName=$instance_type">
<xsl:value-of select="ns:AddInstance($pou_instance_path)"/>
</xsl:when>
<xsl:otherwise>
<xsl:variable name="type_name">
<xsl:value-of select="@typeName"/>
</xsl:variable>
<xsl:apply-templates select="$all_types/ppx:pous/ppx:pou[@name=$type_name] | $all_types/ppx:dataTypes/ppx:dataType[@name=$type_name]">
<xsl:with-param name="instance_path">
<xsl:value-of select="$pou_instance_path"/>
</xsl:with-param>
</xsl:apply-templates>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
<xsl:template match="ppx:pou">
<xsl:param name="instance_path"/>
<xsl:apply-templates select="ppx:interface/*/ppx:variable[ppx:type/ppx:derived]">
<xsl:with-param name="parent_path">
<xsl:value-of select="$instance_path"/>
</xsl:with-param>
</xsl:apply-templates>
</xsl:template>
<xsl:template match="ppx:dataType">
<xsl:param name="instance_path"/>
<xsl:apply-templates select="ppx:baseType/*[self::ppx:derived or self::ppx:struct or self::ppx:array]">
<xsl:with-param name="parent_path">
<xsl:value-of select="$instance_path"/>
</xsl:with-param>
</xsl:apply-templates>
</xsl:template>
<xsl:template match="ppx:variable">
<xsl:param name="parent_path"/>
<xsl:variable name="variable_path">
<xsl:value-of select="$parent_path"/>
<xsl:text>.</xsl:text>
<xsl:value-of select="@name"/>
</xsl:variable>
<xsl:apply-templates select="ppx:type/ppx:derived">
<xsl:with-param name="variable_path">
<xsl:value-of select="$variable_path"/>
</xsl:with-param>
</xsl:apply-templates>
</xsl:template>
<xsl:template match="ppx:derived">
<xsl:param name="variable_path"/>
<xsl:choose>
<xsl:when test="@name=$instance_type">
<xsl:value-of select="ns:AddInstance($variable_path)"/>
</xsl:when>
<xsl:otherwise>
<xsl:variable name="type_name">
<xsl:value-of select="@name"/>
</xsl:variable>
<xsl:apply-templates select="$all_types/ppx:pous/ppx:pou[@name=$type_name] | $all_types/ppx:dataTypes/ppx:dataType[@name=$type_name]">
<xsl:with-param name="instance_path">
<xsl:value-of select="$variable_path"/>
</xsl:with-param>
</xsl:apply-templates>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
<xsl:template match="ppx:struct">
<xsl:param name="variable_path"/>
<xsl:for-each select="ppx:variable[ppx:type/ppx:derived or ppx:type/ppx:struct or ppx:type/ppx:array]">
<xsl:variable name="element_path">
<xsl:value-of select="$variable_path"/>
<xsl:text>.</xsl:text>
<xsl:value-of select="@name"/>
</xsl:variable>
</xsl:for-each>
<xsl:apply-templates select="ppx:type/*[self::ppx:derived or self::ppx:struct or self::ppx:array]">
<xsl:with-param name="variable_path">
<xsl:value-of select="$element_path"/>
</xsl:with-param>
</xsl:apply-templates>
</xsl:template>
<xsl:template match="ppx:array">
<xsl:param name="variable_path"/>
<xsl:apply-templates select="ppx:baseType/*[self::ppx:derived or self::ppx:struct or self::ppx:array]">
<xsl:with-param name="variable_path">
<xsl:value-of select="$variable_path"/>
</xsl:with-param>
</xsl:apply-templates>
</xsl:template>
</xsl:stylesheet>