Source code for icalendar.cal

# -*- coding: utf-8 -*-
"""Calendar is a dictionary like Python object that can render itself as VCAL
files according to rfc2445.

These are the defined components.
"""
from datetime import datetime, timedelta
from icalendar.caselessdict import CaselessDict
from icalendar.parser import Contentline
from icalendar.parser import Contentlines
from icalendar.parser import Parameters
from icalendar.parser import q_join
from icalendar.parser import q_split
from icalendar.parser_tools import DEFAULT_ENCODING
from icalendar.prop import TypesFactory
from icalendar.prop import vText, vDDDLists
from icalendar.timezone_cache import _timezone_cache

import pytz
import dateutil.rrule
from pytz.tzinfo import DstTzInfo


######################################
# The component factory

[docs]class ComponentFactory(CaselessDict): """All components defined in rfc 2445 are registered in this factory class. To get a component you can use it like this. """ def __init__(self, *args, **kwargs): """Set keys to upper for initial dict. """ super(ComponentFactory, self).__init__(*args, **kwargs) self['VEVENT'] = Event self['VTODO'] = Todo self['VJOURNAL'] = Journal self['VFREEBUSY'] = FreeBusy self['VTIMEZONE'] = Timezone self['STANDARD'] = TimezoneStandard self['DAYLIGHT'] = TimezoneDaylight self['VALARM'] = Alarm self['VCALENDAR'] = Calendar # These Properties have multiple property values inlined in one propertyline # seperated by comma. Use CaselessDict as simple caseless set.
INLINE = CaselessDict({ 'CATEGORIES': 1, 'RESOURCES': 1, 'FREEBUSY': 1, }) _marker = []
[docs]class Component(CaselessDict): """Component is the base object for calendar, Event and the other components defined in RFC 2445. normally you will not use this class directy, but rather one of the subclasses. """ name = None # should be defined in each component required = () # These properties are required singletons = () # These properties must only appear once multiple = () # may occur more than once exclusive = () # These properties are mutually exclusive inclusive = () # if any occurs the other(s) MUST occur # ('duration', 'repeat') ignore_exceptions = False # if True, and we cannot parse this # component, we will silently ignore # it, rather than let the exception # propagate upwards # not_compliant = [''] # List of non-compliant properties. def __init__(self, *args, **kwargs): """Set keys to upper for initial dict. """ super(Component, self).__init__(*args, **kwargs) # set parameters here for properties that use non-default values self.subcomponents = [] # Components can be nested. self.is_broken = False # True if we ignored an exception while # parsing a property # def is_compliant(self, name): # """Returns True is the given property name is compliant with the # icalendar implementation. # # If the parser is too strict it might prevent parsing erroneous but # otherwise compliant properties. So the parser is pretty lax, but it is # possible to test for non-complience by calling this method. # """ # return name in not_compliant ############################# # handling of property values def _encode(self, name, value, parameters=None, encode=1): """Encode values to icalendar property values. :param name: Name of the property. :type name: string :param value: Value of the property. Either of a basic Python type of any of the icalendar's own property types. :type value: Python native type or icalendar property type. :param parameters: Property parameter dictionary for the value. Only available, if encode is set to True. :type parameters: Dictionary :param encode: True, if the value should be encoded to one of icalendar's own property types (Fallback is "vText") or False, if not. :type encode: Boolean :returns: icalendar property value """ if not encode: return value if isinstance(value, types_factory.all_types): # Don't encode already encoded values. return value klass = types_factory.for_property(name) obj = klass(value) if parameters: if isinstance(parameters, dict): params = Parameters() for key, item in parameters.items(): params[key] = item parameters = params assert isinstance(parameters, Parameters) obj.params = parameters return obj
[docs] def add(self, name, value, parameters=None, encode=1): """Add a property. :param name: Name of the property. :type name: string :param value: Value of the property. Either of a basic Python type of any of the icalendar's own property types. :type value: Python native type or icalendar property type. :param parameters: Property parameter dictionary for the value. Only available, if encode is set to True. :type parameters: Dictionary :param encode: True, if the value should be encoded to one of icalendar's own property types (Fallback is "vText") or False, if not. :type encode: Boolean :returns: None """ if isinstance(value, datetime) and\ name.lower() in ('dtstamp', 'created', 'last-modified'): # RFC expects UTC for those... force value conversion. if getattr(value, 'tzinfo', False) and value.tzinfo is not None: value = value.astimezone(pytz.utc) else: # assume UTC for naive datetime instances value = pytz.utc.localize(value) # encode value if encode and isinstance(value, list) \ and name.lower() not in ['rdate', 'exdate']: # Individually convert each value to an ical type except rdate and # exdate, where lists of dates might be passed to vDDDLists. value = [self._encode(name, v, parameters, encode) for v in value] else: value = self._encode(name, value, parameters, encode) # set value if name in self: # If property already exists, append it. oldval = self[name] if isinstance(oldval, list): if isinstance(value, list): value = oldval + value else: oldval.append(value) value = oldval else: value = [oldval, value] self[name] = value
def _decode(self, name, value): """Internal for decoding property values. """ # TODO: Currently the decoded method calls the icalendar.prop instances # from_ical. We probably want to decode properties into Python native # types here. But when parsing from an ical string with from_ical, we # want to encode the string into a real icalendar.prop property. if isinstance(value, vDDDLists): # TODO: Workaround unfinished decoding return value decoded = types_factory.from_ical(name, value) # TODO: remove when proper decoded is implemented in every prop.* class # Workaround to decode vText properly if isinstance(decoded, vText): decoded = decoded.encode(DEFAULT_ENCODING) return decoded
[docs] def decoded(self, name, default=_marker): """Returns decoded value of property. """ # XXX: fail. what's this function supposed to do in the end? # -rnix if name in self: value = self[name] if isinstance(value, list): return [self._decode(name, v) for v in value] return self._decode(name, value) else: if default is _marker: raise KeyError(name) else: return default ######################################################################## # Inline values. A few properties have multiple values inlined in in one # property line. These methods are used for splitting and joining these.
[docs] def get_inline(self, name, decode=1): """Returns a list of values (split on comma). """ vals = [v.strip('" ') for v in q_split(self[name])] if decode: return [self._decode(name, val) for val in vals] return vals
[docs] def set_inline(self, name, values, encode=1): """Converts a list of values into comma seperated string and sets value to that. """ if encode: values = [self._encode(name, value, encode=1) for value in values] self[name] = types_factory['inline'](q_join(values)) ######################### # Handling of components
[docs] def add_component(self, component): """Add a subcomponent to this component. """ self.subcomponents.append(component)
def _walk(self, name): """Walk to given component. """ result = [] if name is None or self.name == name: result.append(self) for subcomponent in self.subcomponents: result += subcomponent._walk(name) return result
[docs] def walk(self, name=None): """Recursively traverses component and subcomponents. Returns sequence of same. If name is passed, only components with name will be returned. """ if name is not None: name = name.upper() return self._walk(name) ##################### # Generation
[docs] def property_items(self, recursive=True, sorted=True): """Returns properties in this component and subcomponents as: [(name, value), ...] """ vText = types_factory['text'] properties = [('BEGIN', vText(self.name).to_ical())] if sorted: property_names = self.sorted_keys() else: property_names = self.keys() for name in property_names: values = self[name] if isinstance(values, list): # normally one property is one line for value in values: properties.append((name, value)) else: properties.append((name, values)) if recursive: # recursion is fun! for subcomponent in self.subcomponents: properties += subcomponent.property_items(sorted=sorted) properties.append(('END', vText(self.name).to_ical())) return properties
@classmethod
[docs] def from_ical(cls, st, multiple=False): """Populates the component recursively from a string. """ stack = [] # a stack of components comps = [] for line in Contentlines.from_ical(st): # raw parsing if not line: continue try: name, params, vals = line.parts() except ValueError: # if unable to parse a line within a component # that ignores exceptions, mark the component # as broken and skip the line. otherwise raise. component = stack[-1] if stack else None if not component or not component.ignore_exceptions: raise component.is_broken = True continue uname = name.upper() # check for start of component if uname == 'BEGIN': # try and create one of the components defined in the spec, # otherwise get a general Components for robustness. c_name = vals.upper() c_class = component_factory.get(c_name, cls) component = c_class() if not getattr(component, 'name', ''): # undefined components component.name = c_name stack.append(component) # check for end of event elif uname == 'END': # we are done adding properties to this component # so pop it from the stack and add it to the new top. component = stack.pop() if not stack: # we are at the end comps.append(component) else: if not component.is_broken: stack[-1].add_component(component) if vals == 'VTIMEZONE' and \ 'TZID' in component and \ component['TZID'] not in pytz.all_timezones and \ component['TZID'] not in _timezone_cache: _timezone_cache[component['TZID']] = component.to_tz() # we are adding properties to the current top of the stack else: factory = types_factory.for_property(name) component = stack[-1] datetime_names = ('DTSTART', 'DTEND', 'RECURRENCE-ID', 'DUE', 'FREEBUSY', 'RDATE', 'EXDATE') try: if name in datetime_names and 'TZID' in params: vals = factory(factory.from_ical(vals, params['TZID'])) else: vals = factory(factory.from_ical(vals)) except ValueError: if not component.ignore_exceptions: raise component.is_broken = True else: vals.params = params component.add(name, vals, encode=0) if multiple: return comps if len(comps) > 1: raise ValueError('Found multiple components where ' 'only one is allowed: {st!r}'.format(**locals())) if len(comps) < 1: raise ValueError('Found no components where ' 'exactly one is required: ' '{st!r}'.format(**locals())) return comps[0]
[docs] def content_line(self, name, value, sorted=True): """Returns property as content line. """ params = getattr(value, 'params', Parameters()) return Contentline.from_parts(name, params, value, sorted=sorted)
[docs] def content_lines(self, sorted=True): """Converts the Component and subcomponents into content lines. """ contentlines = Contentlines() for name, value in self.property_items(sorted=sorted): cl = self.content_line(name, value, sorted=sorted) contentlines.append(cl) contentlines.append('') # remember the empty string in the end return contentlines
[docs] def to_ical(self, sorted=True): ''' :param sorted: Whether parameters and properties should be lexicographically sorted. ''' content_lines = self.content_lines(sorted=sorted) return content_lines.to_ical()
def __repr__(self): """String representation of class with all of it's subcomponents. """ subs = ', '.join([str(it) for it in self.subcomponents]) return '%s(%s%s)' % ( self.name or type(self).__name__, dict(self), ', %s' % subs if subs else '' ) ####################################### # components defined in RFC 2445
class Event(Component): name = 'VEVENT' canonical_order = ( 'SUMMARY', 'DTSTART', 'DTEND', 'DURATION', 'DTSTAMP', 'UID', 'RECURRENCE-ID', 'SEQUENCE', 'RRULE' 'EXRULE', 'RDATE', 'EXDATE', ) required = ('UID',) singletons = ( 'CLASS', 'CREATED', 'DESCRIPTION', 'DTSTART', 'GEO', 'LAST-MODIFIED', 'LOCATION', 'ORGANIZER', 'PRIORITY', 'DTSTAMP', 'SEQUENCE', 'STATUS', 'SUMMARY', 'TRANSP', 'URL', 'RECURRENCE-ID', 'DTEND', 'DURATION', 'DTSTART', ) exclusive = ('DTEND', 'DURATION', ) multiple = ( 'ATTACH', 'ATTENDEE', 'CATEGORIES', 'COMMENT', 'CONTACT', 'EXDATE', 'EXRULE', 'RSTATUS', 'RELATED', 'RESOURCES', 'RDATE', 'RRULE' ) ignore_exceptions = True class Todo(Component): name = 'VTODO' required = ('UID',) singletons = ( 'CLASS', 'COMPLETED', 'CREATED', 'DESCRIPTION', 'DTSTAMP', 'DTSTART', 'GEO', 'LAST-MODIFIED', 'LOCATION', 'ORGANIZER', 'PERCENT-COMPLETE', 'PRIORITY', 'RECURRENCE-ID', 'SEQUENCE', 'STATUS', 'SUMMARY', 'UID', 'URL', 'DUE', 'DURATION', ) exclusive = ('DUE', 'DURATION',) multiple = ( 'ATTACH', 'ATTENDEE', 'CATEGORIES', 'COMMENT', 'CONTACT', 'EXDATE', 'EXRULE', 'RSTATUS', 'RELATED', 'RESOURCES', 'RDATE', 'RRULE' ) class Journal(Component): name = 'VJOURNAL' required = ('UID',) singletons = ( 'CLASS', 'CREATED', 'DESCRIPTION', 'DTSTART', 'DTSTAMP', 'LAST-MODIFIED', 'ORGANIZER', 'RECURRENCE-ID', 'SEQUENCE', 'STATUS', 'SUMMARY', 'UID', 'URL', ) multiple = ( 'ATTACH', 'ATTENDEE', 'CATEGORIES', 'COMMENT', 'CONTACT', 'EXDATE', 'EXRULE', 'RELATED', 'RDATE', 'RRULE', 'RSTATUS', ) class FreeBusy(Component): name = 'VFREEBUSY' required = ('UID',) singletons = ( 'CONTACT', 'DTSTART', 'DTEND', 'DURATION', 'DTSTAMP', 'ORGANIZER', 'UID', 'URL', ) multiple = ('ATTENDEE', 'COMMENT', 'FREEBUSY', 'RSTATUS',) class Timezone(Component): name = 'VTIMEZONE' canonical_order = ('TZID', 'STANDARD', 'DAYLIGHT',) required = ('TZID', 'STANDARD', 'DAYLIGHT',) singletons = ('TZID', 'LAST-MODIFIED', 'TZURL',) @staticmethod def _extract_offsets(component, zone): """extract offsets and transition times from a VTIMEZONE component :param component: a STANDARD or DAYLIGHT component :param zone: the name of the zone, used for constructing a TZNAME if this component has none """ try: tzname = str(component['TZNAME']) except KeyError: tzname = '{0}_{1}'.format( zone, component['DTSTART'].to_ical().decode('utf-8') ) offsetfrom = component['TZOFFSETFROM'].td offsetto = component['TZOFFSETTO'].td dtstart = component['DTSTART'].dt # offsets need to be rounded to the next minute, we might loose up # to 30 seconds accuracy, but it can't be helped (datetime # supposedly cannot handle smaller offsets) offsetto_s = int((offsetto.seconds + 30) / 60) * 60 offsetto = timedelta(days=offsetto.days, seconds=offsetto_s) offsetfrom_s = int((offsetfrom.seconds + 30) / 60) * 60 offsetfrom = timedelta(days=offsetfrom.days, seconds=offsetfrom_s) # expand recurrences if 'RRULE' in component: rrulestr = component['RRULE'].to_ical().decode('utf-8') rrule = dateutil.rrule.rrulestr(rrulestr, dtstart=dtstart) if not set(['UNTIL', 'COUNT']).intersection( component['RRULE'].keys()): # pytz.timezones don't know any transition dates after 2038 # either rrule._until = datetime(2038, 12, 31) elif rrule._until.tzinfo: rrule._until = rrule._until.replace(tzinfo=None) transtimes = rrule # or rdates elif 'RDATE' in component: if not isinstance(component['RDATE'], list): rdates = [component['RDATE']] else: rdates = component['RDATE'] transtimes = [dtstart] + [leaf.dt for tree in rdates for leaf in tree.dts] else: transtimes = [dtstart] transitions = [(transtime, offsetfrom, offsetto, tzname) for transtime in set(transtimes)] if component.name == 'STANDARD': is_dst = 0 elif component.name == 'DAYLIGHT': is_dst = 1 return is_dst, transitions def to_tz(self): """convert this VTIMEZONE component to a pytz.timezone object """ zone = str(self['TZID']) transitions = list() dst = dict() for component in self.walk(): if type(component) == Timezone: continue try: tzname = str(component['TZNAME']) except KeyError: tzname = '{0}_{1}'.format( zone, component['DTSTART'].to_ical().decode('utf-8') ) dst[tzname], component_transitions = self._extract_offsets( component, zone ) transitions.extend(component_transitions) transitions.sort() transition_times = [ transtime - osfrom for transtime, osfrom, _, _ in transitions ] # transition_info is a list with tuples in the format # (utcoffset, dstoffset, name) # dstoffset = 0, if current transition is to standard time # = this_utcoffset - prev_standard_utcoffset, otherwise transition_info = list() for num, (transtime, osfrom, osto, name) in enumerate(transitions): dst_offset = False if not dst[name]: dst_offset = timedelta(seconds=0) else: # go back in time until we find a transition to dst for index in range(num - 1, -1, -1): if not dst[transitions[index][3]]: # [3] is the name dst_offset = osto - transitions[index][2] # [2] is osto # noqa break # when the first transition is to dst, we didn't find anything # in the past, so we have to look into the future if not dst_offset: for index in range(num, len(transitions)): if not dst[transitions[index][3]]: # [3] is the name dst_offset = osto - transitions[index][2] # [2] is osto # noqa break transition_info.append((osto, dst_offset, name)) cls = type(zone, (DstTzInfo,), dict( zone=zone, _utc_transition_times=transition_times, _transition_info=transition_info)) return cls() class TimezoneStandard(Component): name = 'STANDARD' required = ('DTSTART', 'TZOFFSETTO', 'TZOFFSETFROM') singletons = ('DTSTART', 'TZOFFSETTO', 'TZOFFSETFROM', 'RRULE') multiple = ('COMMENT', 'RDATE', 'TZNAME') class TimezoneDaylight(Component): name = 'DAYLIGHT' required = ('DTSTART', 'TZOFFSETTO', 'TZOFFSETFROM') singletons = ('DTSTART', 'TZOFFSETTO', 'TZOFFSETFROM', 'RRULE') multiple = ('COMMENT', 'RDATE', 'TZNAME') class Alarm(Component): name = 'VALARM' # not quite sure about these ... required = ('ACTION', 'TRIGGER',) singletons = ('ATTACH', 'ACTION', 'TRIGGER', 'DURATION', 'REPEAT',) inclusive = (('DURATION', 'REPEAT',),)
[docs]class Calendar(Component): """This is the base object for an iCalendar file. """ name = 'VCALENDAR' canonical_order = ('VERSION', 'PRODID', 'CALSCALE', 'METHOD',) required = ('prodid', 'version', ) singletons = ('prodid', 'version', ) multiple = ('calscale', 'method', ) # These are read only singleton, so one instance is enough for the module
types_factory = TypesFactory() component_factory = ComponentFactory()