#

# Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

# All rights reserved.

# This component and the accompanying materials are made available

# under the terms of "Eclipse Public License v1.0"

# which accompanies this distribution, and is available

# at the URL "http://www.eclipse.org/legal/epl-v10.html".

#

# Initial Contributors:

# Nokia Corporation - initial contribution.

#

# Contributors:

#

# Description: 

#

import os

from cone.public import api, exceptions

class PersistenceFactory(api.FactoryBase):

    @classmethod

    def get_reader_for_elem(cls,elemname):

        for reader in ConeReader.__subclasses__():

            if reader.supported_elem(elemname):

                return reader()

        raise exceptions.ConePersistenceError("No reader for given elemname %s found!" % elemname)

    @classmethod

    def get_writer_for_class(cls,classname):

        for writer in ConeWriter.__subclasses__():

            if writer.supported_class(classname):

                return writer ()

        raise exceptions.ConePersistenceError("No writer for given class found!")

class ConeHandler(object):

    ext        = ""

    class_type = ""

class ConeReader(ConeHandler):

    '''

    Read data from the string and return a ConeObject

    '''

    @classmethod

    def supported_elem(cls, elemname, parent=None):

        """

        Class method to determine if this ConeReader supports reading 

        of the given element name

        """

        return False

    def loads(self,data):

        raise exceptions.NotSupportedException()

    def load(self,res):

        raise exceptions.NotSupportedException()

class ConeWriter(object):

    '''

    Write a ConeObject to a string

    '''

    @classmethod

    def supported_class(cls, classname):

        """

        Class method to determine if this ConeWriter supports writing

        of the given class name

        """

        return False

    def dumps(self,ConeObject):

        raise exceptions.NotSupportedException()

    def dump(self,ConeObject,res,indent=True):

        raise exceptions.NotSupportedException()

def indent(elem, level=0):

    i = os.linesep + level*"  "

    if len(elem):

        try:

            if not elem.text or not elem.text.strip():

                elem.text = i + "  "

            for e in elem:

                indent(e, level+1)

                if not e.tail or not e.tail.strip():

                    e.tail = i + "  "

                if not e.tail or not e.tail.strip():

                    e.tail = i

            else:

                if level and (not elem.tail or not elem.tail.strip()):

                    elem.tail = i

        except AttributeError,e:

            # explanation for this kind of try-except required

            pass