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#!/usr/bin/env python

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# -*- coding: utf-8 -*-

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#

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#Copyright (C) 2007: Edouard TISSERANT and Laurent BESSARD

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#

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#See COPYING file for copyrights details.

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#

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#This library is free software; you can redistribute it and/or

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#modify it under the terms of the GNU General Public

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#License as published by the Free Software Foundation; either

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#version 2.1 of the License, or (at your option) any later version.

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#

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#This library is distributed in the hope that it will be useful,

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#but WITHOUT ANY WARRANTY; without even the implied warranty of

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#MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

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#General Public License for more details.

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#

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#You should have received a copy of the GNU General Public

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#License along with this library; if not, write to the Free Software

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#Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

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import traceback

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def LPC_connector_factory(uri, pluginsroot):

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    """

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    This returns the connector to LPC style PLCobject

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    """

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    pluginsroot.logger.write(_("Connecting to URI : %s\n")%uri)

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    servicetype, location = uri.split("://")

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    # Try to get the proxy object

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    try :

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        # TODO: Open Serial Port

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        RemotePLCObjectProxy = LPCObject(pluginsroot) # LPC_PLCObject_Proxy

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    except Exception, msg:

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        pluginsroot.logger.write_error(_("Couldn't connect !\n"))

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        pluginsroot.logger.write_error(traceback.format_exc())

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        return None

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    def LPCCatcher(func, default=None):

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        """

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        A function that catch a pyserial exceptions, write error to logger

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        and return defaul value when it happen

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        """

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        def catcher_func(*args,**kwargs):

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            try:

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                return func(*args,**kwargs)

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            except Exception,e:

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                #pluginsroot.logger.write_error(traceback.format_exc())

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                pluginsroot.logger.write_error(str(e)+"\n")

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                pluginsroot._connector = None

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                return default

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        return catcher_func

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    # Check connection is effective. 

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    # lambda is for getattr of GetPLCstatus to happen inside catcher

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    if LPCCatcher(lambda:RemotePLCObjectProxy.GetPLCstatus())() == None:

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        pluginsroot.logger.write_error(_("Cannot get PLC status - connection failed.\n"))

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        return None

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    class LPCProxy:

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        """

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        A Serial proxy class to handle Beremiz Pyro interface specific behavior.

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        And to put LPC exception catcher in between caller and pyro proxy

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        """

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        def _LPCGetTraceVariables(self):

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            return self.RemotePLCObjectProxy.GetTraceVariables()

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        GetTraceVariables = LPCCatcher(_LPCGetTraceVariables,("Broken",None,None))

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        def _LPCGetPLCstatus(self):

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            return RemotePLCObjectProxy.GetPLCstatus()

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        GetPLCstatus = LPCCatcher(_LPCGetPLCstatus, "Broken")

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        def __getattr__(self, attrName):

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            member = self.__dict__.get(attrName, None)

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            if member is None:

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                def my_local_func(*args,**kwargs):

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                    return RemotePLCObjectProxy.__getattr__(attrName)(*args,**kwargs)

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                member = LPCCatcher(my_local_func, None)

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                self.__dict__[attrName] = member

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            return member

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    return LPCProxy()

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