#!/usr/bin/env python  """ Parsing of vCalendar and iCalendar files.  Copyright (C) 2008, 2009, 2011, 2013, 2014 Paul Boddie <paul@boddie.org.uk>  This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.  This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.  You should have received a copy of the GNU General Public License along with this program.  If not, see <http://www.gnu.org/licenses/>.  --------  References:  RFC 5545: Internet Calendaring and Scheduling Core Object Specification           (iCalendar)           http://tools.ietf.org/html/rfc5545  RFC 2445: Internet Calendaring and Scheduling Core Object Specification           (iCalendar)           http://tools.ietf.org/html/rfc2445 """  import vContent import re  try:     set except NameError:     from sets import Set as set  ParseError = vContent.ParseError  # Format details.  SECTION_TYPES = set([     "VALARM", "VCALENDAR", "VEVENT", "VFREEBUSY", "VJOURNAL", "VTIMEZONE", "VTODO"     ]) QUOTED_PARAMETERS = set([     "ALTREP", "DELEGATED-FROM", "DELEGATED-TO", "DIR", "MEMBER", "SENT-BY"     ]) MULTIVALUED_PARAMETERS = set([     "DELEGATED-FROM", "DELEGATED-TO", "MEMBER"     ]) QUOTED_TYPES = set(["URI"])  unquoted_separator_regexp = re.compile(r"(?<!\\)([,;])")  # Parser classes.  class vCalendarStreamParser(vContent.StreamParser):      "A stream parser specifically for vCalendar/iCalendar."      def next(self):          """         Return the next content item in the file as a tuple of the form         (name, parameters, value).         """          name, parameters, value = vContent.StreamParser.next(self)         return name, self.decode_parameters(parameters), value      def decode_content(self, value):          """         Decode the given 'value' (which may represent a collection of distinct         values), replacing quoted separator characters.         """          sep = None         values = []          for i, s in enumerate(unquoted_separator_regexp.split(value)):             if i % 2 != 0:                 if not sep:                     sep = s                 continue             values.append(self.decode_content_value(s))          if sep == ",":             return values         elif sep == ";":             return tuple(values)         else:             return values[0]      def decode_content_value(self, value):          "Decode the given 'value', replacing quoted separator characters."          # Replace quoted characters (see 4.3.11 in RFC 2445).          value = vContent.StreamParser.decode_content(self, value)         return value.replace(r"\,", ",").replace(r"\;", ";")      # Internal methods.      def decode_quoted_value(self, value):          "Decode the given 'value', returning a list of decoded values."          if value[0] == '"' and value[-1] == '"':             return value[1:-1]         else:             return value      def decode_parameters(self, parameters):          """         Decode the given 'parameters' according to the vCalendar specification.         """          decoded_parameters = {}          for param_name, param_value in parameters.items():             if param_name in QUOTED_PARAMETERS:                 param_value = self.decode_quoted_value(param_value)                 separator = '","'             else:                 separator = ","             if param_name in MULTIVALUED_PARAMETERS:                 param_value = param_value.split(separator)             decoded_parameters[param_name] = param_value          return decoded_parameters  class vCalendarParser(vContent.Parser):      "A parser specifically for vCalendar/iCalendar."      def parse(self, f, parser_cls=None):         return vContent.Parser.parse(self, f, (parser_cls or vCalendarStreamParser))  # Writer classes.  class vCalendarStreamWriter(vContent.StreamWriter):      "A stream writer specifically for vCalendar."      # Overridden methods.      def write(self, name, parameters, value):          """         Write a content line, serialising the given 'name', 'parameters' and         'value' information.         """          if name in SECTION_TYPES:             self.write_content_line("BEGIN", {}, name)             for n, p, v in value:                 self.write(n, p, v)             self.write_content_line("END", {}, name)         else:             vContent.StreamWriter.write(self, name, parameters, value)      def encode_parameters(self, parameters):          """         Encode the given 'parameters' according to the vCalendar specification.         """          encoded_parameters = {}          for param_name, param_value in parameters.items():             if param_name in QUOTED_PARAMETERS:                 param_value = self.encode_quoted_parameter_value(param_value)                 separator = '","'             else:                 separator = ","             if param_name in MULTIVALUED_PARAMETERS:                 param_value = separator.join(param_value)             encoded_parameters[param_name] = param_value          return encoded_parameters      def encode_content(self, value):          """         Encode the given 'value' (which may be a list or tuple of separate         values), quoting characters and separating collections of values.         """          if isinstance(value, list):             sep = ","         elif isinstance(value, tuple):             sep = ";"         else:             value = [value]             sep = ""          return sep.join([self.encode_content_value(v) for v in value])      def encode_content_value(self, value):          "Encode the given 'value', quoting characters."          # Replace quoted characters (see 4.3.11 in RFC 2445).          value = vContent.StreamWriter.encode_content(self, value)         return value.replace(";", r"\;").replace(",", r"\,")  # Public functions.  def parse(stream_or_string, encoding=None, non_standard_newline=0):      """     Parse the resource data found through the use of the 'stream_or_string',     which is either a stream providing Unicode data (the codecs module can be     used to open files or to wrap streams in order to provide Unicode data) or a     filename identifying a file to be parsed.      The optional 'encoding' can be used to specify the character encoding used     by the file to be parsed.      The optional 'non_standard_newline' can be set to a true value (unlike the     default) in order to attempt to process files with CR as the end of line     character.      As a result of parsing the resource, the root node of the imported resource     is returned.     """      return vContent.parse(stream_or_string, encoding, non_standard_newline, vCalendarParser)  def iterparse(stream_or_string, encoding=None, non_standard_newline=0):      """     Parse the resource data found through the use of the 'stream_or_string',     which is either a stream providing Unicode data (the codecs module can be     used to open files or to wrap streams in order to provide Unicode data) or a     filename identifying a file to be parsed.      The optional 'encoding' can be used to specify the character encoding used     by the file to be parsed.      The optional 'non_standard_newline' can be set to a true value (unlike the     default) in order to attempt to process files with CR as the end of line     character.      An iterator is returned which provides event tuples describing parsing     events of the form (name, parameters, value).     """      return vContent.iterparse(stream_or_string, encoding, non_standard_newline, vCalendarStreamParser)  def iterwrite(stream_or_string=None, write=None, encoding=None, line_length=None):      """     Return a writer which will either send data to the resource found through     the use of 'stream_or_string' or using the given 'write' operation.      The 'stream_or_string' parameter may be either a stream accepting Unicode     data (the codecs module can be used to open files or to wrap streams in     order to accept Unicode data) or a filename identifying a file to be     written.      The optional 'encoding' can be used to specify the character encoding used     by the file to be written.      The optional 'line_length' can be used to specify how long lines should be     in the resulting data.     """      return vContent.iterwrite(stream_or_string, write, encoding, line_length, vCalendarStreamWriter)  def to_dict(node):      "Return the 'node' converted to a dictionary representation."      return vContent.to_dict(node, SECTION_TYPES)  to_node = vContent.to_node  # vim: tabstop=4 expandtab shiftwidth=4