#============================================================================ 

#Name        : escapeddict.py 

#Part of     : Helium 

#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 the License "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:

#===============================================================================

""" This class enables developer to use ${xxx} pattern in their dict and 

    get them replaced recursively.

"""

import re

import types

import UserDict

class _CustomArray(list):

    """ Internal class

    """

    def __str__(self):

        string = ""

        for elem in self:

            string += " "+elem

        return string

class EscapedDict(UserDict.UserDict):

    """ Implements a dictionary that escapes the key values recursively. """        

        UserDict.UserDict.__init__(self, dict)

        self.__failonerror = failonerror

    def __getitem__(self, key):

        """ Overrides the usual __getitem__ to insert values of other keys referenced in this key's

        value. """

        if key in self.data:

            value = self.data[key]

            result = value

            if isinstance(value, types.ListType):

                result = _CustomArray()

                for elem in value:

                    (string, changes) = re.subn(r'\${(?P<name>[._a-zA-Z0-9]+)}', r'%(\g<name>)s', elem)

                    if changes > 0:

                        result.append(string % self)

                    else:

                        result.append(elem)

            else:

                (string, changes) = re.subn(r'\${(?P<name>[._a-zA-Z0-9]+)}', r'%(\g<name>)s', value)

                if changes > 0:

                    result = string % self

            return result

        elif not self.__failonerror:

            return "${%s}" % key

        raise KeyError("Could not find key '%s'" % key)

def escapeString(input_string, config):

    """ Escape a string recursively.

    :param input_string: the string to be escaped.

    :param config: a dictionnary containing the values to escape.

    :return: the escaped string.

    """

    data = EscapedDict(config)

    match = re.search(r'\${(?P<name>[._a-zA-Z0-9]+)}', input_string)

    if match != None:

        for property_name in match.groups():

            property_value = data[property_name]

            property_value = re.sub(r'\\', r'\\\\', property_value)

            input_string = re.sub('\${' + property_name + '}', property_value, input_string)

    return input_string