controls/UriLocationEditor.py
author Andrey Skvortsov <andrej.skvortzov@gmail.com>
Fri, 24 Aug 2018 13:41:43 +0300
changeset 2297 96ca6b056c55
parent 2182 eeca1aff0691
child 2329 e5703dc8848e
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
from __future__ import absolute_import

import wx
from zope.interface import Interface, Attribute
from zope.interface.verify import verifyObject
from connectors import connectors_dialog, ConnectorDialog, GetConnectorFromURI


[ID_URIWIZARDDIALOG, ID_URITYPECHOICE] = [wx.NewId() for _init_ctrls in range(2)]


class IConnectorPanel(Interface):
    """This is interface for panel of seperate connector type"""
    uri = Attribute("""uri of connections""")
    type = Attribute("""type of connector""")

    def SetURI(uri):     # pylint: disable=no-self-argument
        """methode for set uri"""

    def GetURI():        # pylint: disable=no-self-argument
        """metohde for get uri"""


class UriLocationEditor(wx.Dialog):
    def _init_ctrls(self, parent):
        self.UriTypeChoice = wx.Choice(parent=self, id=ID_URIWIZARDDIALOG, choices=self.URITYPES)
        self.UriTypeChoice.SetSelection(0)
        self.Bind(wx.EVT_CHOICE, self.OnTypeChoice, self.UriTypeChoice)
        self.PanelSizer = wx.BoxSizer(wx.HORIZONTAL)
        self.ButtonSizer = self.CreateButtonSizer(wx.OK | wx.CANCEL)

    def _init_sizers(self):
        self.mainSizer = wx.BoxSizer(wx.VERTICAL)
        typeSizer = wx.BoxSizer(wx.HORIZONTAL)
        typeSizer.Add(wx.StaticText(self, wx.ID_ANY, _("URI type:")), border=5, flag=wx.ALIGN_CENTER_VERTICAL | wx.ALL)
        typeSizer.Add(self.UriTypeChoice, border=5, flag=wx.ALL)
        self.mainSizer.Add(typeSizer)

        self.mainSizer.Add(self.PanelSizer, border=5, flag=wx.ALL)
        self.mainSizer.Add(self.ButtonSizer, border=5, flag=wx.BOTTOM | wx.ALIGN_CENTER_HORIZONTAL)
        self.SetSizer(self.mainSizer)
        self.Layout()
        self.Fit()

    def __init__(self, parent, uri):
        wx.Dialog.__init__(self, id=ID_URIWIZARDDIALOG,
                           name='UriLocationEditor', parent=parent,
                           title='Uri location')
        self.URITYPES = [_("- Select URI type -")]
        for connector_type, connector_function in connectors_dialog.iteritems():
            try:
                connector_function['function']()
                self.URITYPES.append(connector_type)
            except Exception:
                pass

        self.selected = None
        self.parrent = parent
        self.logger = self.parrent.CTR.logger
        self._init_ctrls(parent)
        self._init_sizers()
        self.SetURI(uri)
        self.CenterOnParent()

    def OnTypeChoice(self, event):
        self._removePanelType()
        index = event.GetSelection()
        if index > 0:
            self.selected = event.GetString()
            self.panelType = self._getConnectorDialog(self.selected)
            if self.panelType:
                self.PanelSizer.Add(self.panelType)
                self.mainSizer.Layout()
                self.Fit()
                self.panelType.Refresh()

    def SetURI(self, uri):
        self._removePanelType()
        uri_list = uri.strip().split(":")
        if uri_list:
            uri_type = uri_list[0].upper()
            type = GetConnectorFromURI(uri_type)
            if type:
                self.selected = type
                self.UriTypeChoice.SetStringSelection(self.selected)
                self.panelType = self._getConnectorDialog(self.selected)
                if self.panelType:
                    self.panelType.SetURI(uri)
                    self.PanelSizer.Add(self.panelType)
                    self.PanelSizer.Layout()
                    self.mainSizer.Layout()
                    self.Fit()
                    self.panelType.Refresh()

    def GetURI(self):
        if not self.selected or not self.panelType:
            return ""
        else:
            return self.panelType.GetURI()

    def _removePanelType(self):
        for i in range(self.PanelSizer.GetItemCount()):
            item = self.PanelSizer.GetItem(i)
            item.DeleteWindows()
            self.PanelSizer.Remove(i)
            self.Fit()
        self.PanelSizer.Layout()

    def _getConnectorDialog(self, connectorType):
        connector = ConnectorDialog(connectorType, self)
        if connector and IConnectorPanel.providedBy(connector):
            if verifyObject(IConnectorPanel, connector):
                return connector
        else:
            return None