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radicale/radicale_vobject/icalendar.py

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Fork vobject
2018-04-26 00:05:03 +02:00
"""Definitions and behavior for iCalendar, also known as vCalendar 2.0"""
from __future__ import print_function
import datetime
import logging
import random # for generating a UID
import socket
import string
import base64
from dateutil import rrule, tz
import six
try:
import pytz
except ImportError:
class Pytz:
"""fake pytz module (pytz is not required)"""
class AmbiguousTimeError(Exception):
"""pytz error for ambiguous times
during transition daylight->standard"""
class NonExistentTimeError(Exception):
"""pytz error for non-existent times
during transition standard->daylight"""
pytz = Pytz # keeps quantifiedcode happy
from . import behavior
from .base import (VObjectError, NativeError, ValidateError, ParseError,
Component, ContentLine, logger, registerBehavior,
backslashEscape, foldOneLine)
# ------------------------------- Constants ------------------------------------
DATENAMES = ("rdate", "exdate")
RULENAMES = ("exrule", "rrule")
DATESANDRULES = ("exrule", "rrule", "rdate", "exdate")
PRODID = u"-//PYVOBJECT//NONSGML Version 1//EN"
WEEKDAYS = "MO", "TU", "WE", "TH", "FR", "SA", "SU"
FREQUENCIES = ('YEARLY', 'MONTHLY', 'WEEKLY', 'DAILY', 'HOURLY', 'MINUTELY',
'SECONDLY')
zeroDelta = datetime.timedelta(0)
twoHours = datetime.timedelta(hours=2)
# ---------------------------- TZID registry -----------------------------------
__tzidMap = {}
def toUnicode(s):
"""
Take a string or unicode, turn it into unicode, decoding as utf-8
"""
if isinstance(s, six.binary_type):
s = s.decode('utf-8')
return s
def registerTzid(tzid, tzinfo):
"""
Register a tzid -> tzinfo mapping.
"""
__tzidMap[toUnicode(tzid)] = tzinfo
def getTzid(tzid, smart=True):
"""
Return the tzid if it exists, or None.
"""
tz = __tzidMap.get(toUnicode(tzid), None)
if smart and tzid and not tz:
try:
from pytz import timezone, UnknownTimeZoneError
try:
tz = timezone(tzid)
registerTzid(toUnicode(tzid), tz)
except UnknownTimeZoneError as e:
logging.error(e)
except ImportError as e:
logging.error(e)
return tz
utc = tz.tzutc()
registerTzid("UTC", utc)
# -------------------- Helper subclasses ---------------------------------------
class TimezoneComponent(Component):
"""
A VTIMEZONE object.
VTIMEZONEs are parsed by tz.tzical, the resulting datetime.tzinfo
subclass is stored in self.tzinfo, self.tzid stores the TZID associated
with this timezone.
@ivar name:
The uppercased name of the object, in this case always 'VTIMEZONE'.
@ivar tzinfo:
A datetime.tzinfo subclass representing this timezone.
@ivar tzid:
The string used to refer to this timezone.
"""
def __init__(self, tzinfo=None, *args, **kwds):
"""
Accept an existing Component or a tzinfo class.
"""
super(TimezoneComponent, self).__init__(*args, **kwds)
self.isNative = True
# hack to make sure a behavior is assigned
if self.behavior is None:
self.behavior = VTimezone
if tzinfo is not None:
self.tzinfo = tzinfo
if not hasattr(self, 'name') or self.name == '':
self.name = 'VTIMEZONE'
self.useBegin = True
@classmethod
def registerTzinfo(obj, tzinfo):
"""
Register tzinfo if it's not already registered, return its tzid.
"""
tzid = obj.pickTzid(tzinfo)
if tzid and not getTzid(tzid, False):
registerTzid(tzid, tzinfo)
return tzid
def gettzinfo(self):
# workaround for dateutil failing to parse some experimental properties
good_lines = ('rdate', 'rrule', 'dtstart', 'tzname', 'tzoffsetfrom',
'tzoffsetto', 'tzid')
# serialize encodes as utf-8, cStringIO will leave utf-8 alone
buffer = six.StringIO()
# allow empty VTIMEZONEs
if len(self.contents) == 0:
return None
def customSerialize(obj):
if isinstance(obj, Component):
foldOneLine(buffer, u"BEGIN:" + obj.name)
for child in obj.lines():
if child.name.lower() in good_lines:
child.serialize(buffer, 75, validate=False)
for comp in obj.components():
customSerialize(comp)
foldOneLine(buffer, u"END:" + obj.name)
customSerialize(self)
buffer.seek(0) # tzical wants to read a stream
return tz.tzical(buffer).get()
def settzinfo(self, tzinfo, start=2000, end=2030):
"""
Create appropriate objects in self to represent tzinfo.
Collapse DST transitions to rrules as much as possible.
Assumptions:
- DST <-> Standard transitions occur on the hour
- never within a month of one another
- twice or fewer times a year
- never in the month of December
- DST always moves offset exactly one hour later
- tzinfo classes dst method always treats times that could be in either
offset as being in the later regime
"""
def fromLastWeek(dt):
"""
How many weeks from the end of the month dt is, starting from 1.
"""
weekDelta = datetime.timedelta(weeks=1)
n = 1
current = dt + weekDelta
while current.month == dt.month:
n += 1
current += weekDelta
return n
# lists of dictionaries defining rules which are no longer in effect
completed = {'daylight': [], 'standard': []}
# dictionary defining rules which are currently in effect
working = {'daylight': None, 'standard': None}
# rule may be based on nth week of the month or the nth from the last
for year in range(start, end + 1):
newyear = datetime.datetime(year, 1, 1)
for transitionTo in 'daylight', 'standard':
transition = getTransition(transitionTo, year, tzinfo)
oldrule = working[transitionTo]
if transition == newyear:
# transitionTo is in effect for the whole year
rule = {'end' : None,
'start' : newyear,
'month' : 1,
'weekday' : None,
'hour' : None,
'plus' : None,
'minus' : None,
'name' : tzinfo.tzname(newyear),
'offset' : tzinfo.utcoffset(newyear),
'offsetfrom' : tzinfo.utcoffset(newyear)}
if oldrule is None:
# transitionTo was not yet in effect
working[transitionTo] = rule
else:
# transitionTo was already in effect
if (oldrule['offset'] != tzinfo.utcoffset(newyear)):
# old rule was different, it shouldn't continue
oldrule['end'] = year - 1
completed[transitionTo].append(oldrule)
working[transitionTo] = rule
elif transition is None:
# transitionTo is not in effect
if oldrule is not None:
# transitionTo used to be in effect
oldrule['end'] = year - 1
completed[transitionTo].append(oldrule)
working[transitionTo] = None
else:
# an offset transition was found
try:
old_offset = tzinfo.utcoffset(transition - twoHours)
name = tzinfo.tzname(transition)
offset = tzinfo.utcoffset(transition)
except (pytz.AmbiguousTimeError, pytz.NonExistentTimeError):
# guaranteed that tzinfo is a pytz timezone
is_dst = (transitionTo == "daylight")
old_offset = tzinfo.utcoffset(transition - twoHours, is_dst=is_dst)
name = tzinfo.tzname(transition, is_dst=is_dst)
offset = tzinfo.utcoffset(transition, is_dst=is_dst)
rule = {'end' : None, # None, or an integer year
'start' : transition, # the datetime of transition
'month' : transition.month,
'weekday' : transition.weekday(),
'hour' : transition.hour,
'name' : name,
'plus' : int(
(transition.day - 1)/ 7 + 1), # nth week of the month
'minus' : fromLastWeek(transition), # nth from last week
'offset' : offset,
'offsetfrom' : old_offset}
if oldrule is None:
working[transitionTo] = rule
else:
plusMatch = rule['plus'] == oldrule['plus']
minusMatch = rule['minus'] == oldrule['minus']
truth = plusMatch or minusMatch
for key in 'month', 'weekday', 'hour', 'offset':
truth = truth and rule[key] == oldrule[key]
if truth:
# the old rule is still true, limit to plus or minus
if not plusMatch:
oldrule['plus'] = None
if not minusMatch:
oldrule['minus'] = None
else:
# the new rule did not match the old
oldrule['end'] = year - 1
completed[transitionTo].append(oldrule)
working[transitionTo] = rule
for transitionTo in 'daylight', 'standard':
if working[transitionTo] is not None:
completed[transitionTo].append(working[transitionTo])
self.tzid = []
self.daylight = []
self.standard = []
self.add('tzid').value = self.pickTzid(tzinfo, True)
# old = None # unused?
for transitionTo in 'daylight', 'standard':
for rule in completed[transitionTo]:
comp = self.add(transitionTo)
dtstart = comp.add('dtstart')
dtstart.value = rule['start']
if rule['name'] is not None:
comp.add('tzname').value = rule['name']
line = comp.add('tzoffsetto')
line.value = deltaToOffset(rule['offset'])
line = comp.add('tzoffsetfrom')
line.value = deltaToOffset(rule['offsetfrom'])
if rule['plus'] is not None:
num = rule['plus']
elif rule['minus'] is not None:
num = -1 * rule['minus']
else:
num = None
if num is not None:
dayString = ";BYDAY=" + str(num) + WEEKDAYS[rule['weekday']]
else:
dayString = ""
if rule['end'] is not None:
if rule['hour'] is None:
# all year offset, with no rule
endDate = datetime.datetime(rule['end'], 1, 1)
else:
weekday = rrule.weekday(rule['weekday'], num)
du_rule = rrule.rrule(rrule.YEARLY,
bymonth=rule['month'], byweekday=weekday,
dtstart=datetime.datetime(
rule['end'], 1, 1, rule['hour']
)
)
endDate = du_rule[0]
endDate = endDate.replace(tzinfo=utc) - rule['offsetfrom']
endString = ";UNTIL=" + dateTimeToString(endDate)
else:
endString = ''
new_rule = "FREQ=YEARLY{0!s};BYMONTH={1!s}{2!s}"\
.format(dayString, rule['month'], endString)
comp.add('rrule').value = new_rule
tzinfo = property(gettzinfo, settzinfo)
# prevent Component's __setattr__ from overriding the tzinfo property
normal_attributes = Component.normal_attributes + ['tzinfo']
@staticmethod
def pickTzid(tzinfo, allowUTC=False):
"""
Given a tzinfo class, use known APIs to determine TZID, or use tzname.
"""
if tzinfo is None or (not allowUTC and tzinfo_eq(tzinfo, utc)):
# If tzinfo is UTC, we don't need a TZID
return None
# try PyICU's tzid key
if hasattr(tzinfo, 'tzid'):
return toUnicode(tzinfo.tzid)
# try pytz zone key
if hasattr(tzinfo, 'zone'):
return toUnicode(tzinfo.zone)
# try tzical's tzid key
elif hasattr(tzinfo, '_tzid'):
return toUnicode(tzinfo._tzid)
else:
# return tzname for standard (non-DST) time
notDST = datetime.timedelta(0)
for month in range(1, 13):
dt = datetime.datetime(2000, month, 1)
if tzinfo.dst(dt) == notDST:
return toUnicode(tzinfo.tzname(dt))
# there was no standard time in 2000!
raise VObjectError("Unable to guess TZID for tzinfo {0!s}"
.format(tzinfo))
def __str__(self):
return "<VTIMEZONE | {0}>".format(getattr(self, 'tzid', 'No TZID'))
def __repr__(self):
return self.__str__()
def prettyPrint(self, level, tabwidth):
pre = ' ' * level * tabwidth
print(pre, self.name)
print(pre, "TZID:", self.tzid)
print('')
class RecurringComponent(Component):
"""
A vCalendar component like VEVENT or VTODO which may recur.
Any recurring component can have one or multiple RRULE, RDATE,
EXRULE, or EXDATE lines, and one or zero DTSTART lines. It can also have a
variety of children that don't have any recurrence information.
In the example below, note that dtstart is included in the rruleset.
This is not the default behavior for dateutil's rrule implementation unless
dtstart would already have been a member of the recurrence rule, and as a
result, COUNT is wrong. This can be worked around when getting rruleset by
adjusting count down by one if an rrule has a count and dtstart isn't in its
result set, but by default, the rruleset property doesn't do this work
around, to access it getrruleset must be called with addRDate set True.
@ivar rruleset:
A U{rruleset<https://moin.conectiva.com.br/DateUtil>}.
"""
def __init__(self, *args, **kwds):
super(RecurringComponent, self).__init__(*args, **kwds)
self.isNative = True
def getrruleset(self, addRDate=False):
"""
Get an rruleset created from self.
If addRDate is True, add an RDATE for dtstart if it's not included in
an RRULE or RDATE, and count is decremented if it exists.
Note that for rules which don't match DTSTART, DTSTART may not appear
in list(rruleset), although it should. By default, an RDATE is not
created in these cases, and count isn't updated, so dateutil may list
a spurious occurrence.
"""
rruleset = None
for name in DATESANDRULES:
addfunc = None
for line in self.contents.get(name, ()):
# don't bother creating a rruleset unless there's a rule
if rruleset is None:
rruleset = rrule.rruleset()
if addfunc is None:
addfunc = getattr(rruleset, name)
dtstart = self.dtstart.value
if name in DATENAMES:
if type(line.value[0]) == datetime.datetime:
list(map(addfunc, line.value))
elif type(line.value[0]) == datetime.date:
for dt in line.value:
addfunc(datetime.datetime(dt.year, dt.month, dt.day))
else:
# ignore RDATEs with PERIOD values for now
pass
elif name in RULENAMES:
try:
dtstart = self.dtstart.value
except (AttributeError, KeyError):
# Special for VTODO - try DUE property instead
try:
if self.name == "VTODO":
dtstart = self.due.value
else:
# if there's no dtstart, just return None
logging.error('failed to get dtstart with VTODO')
return None
except (AttributeError, KeyError):
# if there's no due, just return None
logging.error('failed to find DUE at all.')
return None
# a Ruby iCalendar library escapes semi-colons in rrules,
# so also remove any backslashes
value = line.value.replace('\\', '')
rule = rrule.rrulestr(
value, dtstart=dtstart,
# If dtstart has no time zone, `until`
# shouldn't get one, either:
ignoretz=isinstance(dtstart, datetime.date))
until = rule._until
if until is not None and isinstance(dtstart,
datetime.datetime) and \
(until.tzinfo != dtstart.tzinfo):
# dateutil converts the UNTIL date to a datetime,
# check to see if the UNTIL parameter value was a date
vals = dict(pair.split('=') for pair in
line.value.upper().split(';'))
if len(vals.get('UNTIL', '')) == 8:
until = datetime.datetime.combine(until.date(),
dtstart.time())
# While RFC2445 says UNTIL MUST be UTC, Chandler allows
# floating recurring events, and uses floating UNTIL
# values. Also, some odd floating UNTIL but timezoned
# DTSTART values have shown up in the wild, so put
# floating UNTIL values DTSTART's timezone
if until.tzinfo is None:
until = until.replace(tzinfo=dtstart.tzinfo)
if dtstart.tzinfo is not None:
until = until.astimezone(dtstart.tzinfo)
# RFC2445 actually states that UNTIL must be a UTC
# value. Whilst the changes above work OK, one problem
# case is if DTSTART is floating but UNTIL is properly
# specified as UTC (or with a TZID). In that case
# dateutil will fail datetime comparisons. There is no
# easy solution to this as there is no obvious timezone
# (at this point) to do proper floating time offset
# comparisons. The best we can do is treat the UNTIL
# value as floating. This could mean incorrect
# determination of the last instance. The better
# solution here is to encourage clients to use COUNT
# rather than UNTIL when DTSTART is floating.
if dtstart.tzinfo is None:
until = until.replace(tzinfo=None)
rule._until = until
# add the rrule or exrule to the rruleset
addfunc(rule)
if (name == 'rrule' or name == 'rdate') and addRDate:
# rlist = rruleset._rrule if name == 'rrule' else rruleset._rdate
try:
# dateutils does not work with all-day
# (datetime.date) items so we need to convert to a
# datetime.datetime (which is what dateutils
# does internally)
if not isinstance(dtstart, datetime.datetime):
adddtstart = datetime.datetime.fromordinal(dtstart.toordinal())
else:
adddtstart = dtstart
if name == 'rrule':
if rruleset._rrule[-1][0] != adddtstart:
rruleset.rdate(adddtstart)
added = True
if rruleset._rrule[-1]._count is not None:
rruleset._rrule[-1]._count -= 1
else:
added = False
elif name == 'rdate':
if rruleset._rdate[0] != adddtstart:
rruleset.rdate(adddtstart)
added = True
else:
added = False
except IndexError:
# it's conceivable that an rrule has 0 datetimes
added = False
return rruleset
def setrruleset(self, rruleset):
# Get DTSTART from component (or DUE if no DTSTART in a VTODO)
try:
dtstart = self.dtstart.value
except (AttributeError, KeyError):
if self.name == "VTODO":
dtstart = self.due.value
else:
raise
isDate = datetime.date == type(dtstart)
if isDate:
dtstart = datetime.datetime(dtstart.year, dtstart.month, dtstart.day)
untilSerialize = dateToString
else:
# make sure to convert time zones to UTC
untilSerialize = lambda x: dateTimeToString(x, True)
for name in DATESANDRULES:
if name in self.contents:
del self.contents[name]
setlist = getattr(rruleset, '_' + name)
if name in DATENAMES:
setlist = list(setlist) # make a copy of the list
if name == 'rdate' and dtstart in setlist:
setlist.remove(dtstart)
if isDate:
setlist = [dt.date() for dt in setlist]
if len(setlist) > 0:
self.add(name).value = setlist
elif name in RULENAMES:
for rule in setlist:
buf = six.StringIO()
buf.write('FREQ=')
buf.write(FREQUENCIES[rule._freq])
values = {}
if rule._interval != 1:
values['INTERVAL'] = [str(rule._interval)]
if rule._wkst != 0: # wkst defaults to Monday
values['WKST'] = [WEEKDAYS[rule._wkst]]
if rule._bysetpos is not None:
values['BYSETPOS'] = [str(i) for i in rule._bysetpos]
if rule._count is not None:
values['COUNT'] = [str(rule._count)]
elif rule._until is not None:
values['UNTIL'] = [untilSerialize(rule._until)]
days = []
if (rule._byweekday is not None and (
rrule.WEEKLY != rule._freq or
len(rule._byweekday) != 1 or
rule._dtstart.weekday() != rule._byweekday[0])):
# ignore byweekday if freq is WEEKLY and day correlates
# with dtstart because it was automatically set by dateutil
days.extend(WEEKDAYS[n] for n in rule._byweekday)
if rule._bynweekday is not None:
days.extend(n + WEEKDAYS[day] for day, n in rule._bynweekday)
if len(days) > 0:
values['BYDAY'] = days
if rule._bymonthday is not None and len(rule._bymonthday) > 0:
if not (rule._freq <= rrule.MONTHLY and
len(rule._bymonthday) == 1 and
rule._bymonthday[0] == rule._dtstart.day):
# ignore bymonthday if it's generated by dateutil
values['BYMONTHDAY'] = [str(n) for n in rule._bymonthday]
if rule._bynmonthday is not None and len(rule._bynmonthday) > 0:
values.setdefault('BYMONTHDAY', []).extend(str(n) for n in rule._bynmonthday)
if rule._bymonth is not None and len(rule._bymonth) > 0:
if (rule._byweekday is not None or
len(rule._bynweekday or ()) > 0 or
not (rule._freq == rrule.YEARLY and
len(rule._bymonth) == 1 and
rule._bymonth[0] == rule._dtstart.month)):
# ignore bymonth if it's generated by dateutil
values['BYMONTH'] = [str(n) for n in rule._bymonth]
if rule._byyearday is not None:
values['BYYEARDAY'] = [str(n) for n in rule._byyearday]
if rule._byweekno is not None:
values['BYWEEKNO'] = [str(n) for n in rule._byweekno]
# byhour, byminute, bysecond are always ignored for now
for key, paramvals in values.items():
buf.write(';')
buf.write(key)
buf.write('=')
buf.write(','.join(paramvals))
self.add(name).value = buf.getvalue()
rruleset = property(getrruleset, setrruleset)
def __setattr__(self, name, value):
"""
For convenience, make self.contents directly accessible.
"""
if name == 'rruleset':
self.setrruleset(value)
else:
super(RecurringComponent, self).__setattr__(name, value)
class TextBehavior(behavior.Behavior):
"""
Provide backslash escape encoding/decoding for single valued properties.
TextBehavior also deals with base64 encoding if the ENCODING parameter is
explicitly set to BASE64.
"""
base64string = 'BASE64' # vCard uses B
@classmethod
def decode(cls, line):
"""
Remove backslash escaping from line.value.
"""
if line.encoded:
encoding = getattr(line, 'encoding_param', None)
if encoding and encoding.upper() == cls.base64string:
line.value = base64.b64decode(line.value)
else:
line.value = stringToTextValues(line.value)[0]
line.encoded = False
@classmethod
def encode(cls, line):
"""
Backslash escape line.value.
"""
if not line.encoded:
encoding = getattr(line, 'encoding_param', None)
if encoding and encoding.upper() == cls.base64string:
line.value = base64.b64encode(line.value.encode('utf-8')).decode('utf-8').replace('\n', '')
else:
line.value = backslashEscape(line.value)
line.encoded = True
class VCalendarComponentBehavior(behavior.Behavior):
defaultBehavior = TextBehavior
isComponent = True
class RecurringBehavior(VCalendarComponentBehavior):
"""
Parent Behavior for components which should be RecurringComponents.
"""
hasNative = True
@staticmethod
def transformToNative(obj):
"""
Turn a recurring Component into a RecurringComponent.
"""
if not obj.isNative:
object.__setattr__(obj, '__class__', RecurringComponent)
obj.isNative = True
return obj
@staticmethod
def transformFromNative(obj):
if obj.isNative:
object.__setattr__(obj, '__class__', Component)
obj.isNative = False
return obj
@staticmethod
def generateImplicitParameters(obj):
"""
Generate a UID and DTSTAMP if one does not exist.
This is just a dummy implementation, for now.
"""
if not hasattr(obj, 'uid'):
rand = int(random.random() * 100000)
now = datetime.datetime.now(utc)
now = dateTimeToString(now)
host = socket.gethostname()
obj.add(ContentLine('UID', [], "{0} - {1}@{2}".format(now, rand,
host)))
if not hasattr(obj, 'dtstamp'):
now = datetime.datetime.now(utc)
obj.add('dtstamp').value = now
class DateTimeBehavior(behavior.Behavior):
"""
Parent Behavior for ContentLines containing one DATE-TIME.
"""
hasNative = True
@staticmethod
def transformToNative(obj):
"""
Turn obj.value into a datetime.
RFC2445 allows times without time zone information, "floating times"
in some properties. Mostly, this isn't what you want, but when parsing
a file, real floating times are noted by setting to 'TRUE' the
X-VOBJ-FLOATINGTIME-ALLOWED parameter.
"""
if obj.isNative:
return obj
obj.isNative = True
if obj.value == '':
return obj
obj.value = obj.value
# we're cheating a little here, parseDtstart allows DATE
obj.value = parseDtstart(obj)
if obj.value.tzinfo is None:
obj.params['X-VOBJ-FLOATINGTIME-ALLOWED'] = ['TRUE']
if obj.params.get('TZID'):
# Keep a copy of the original TZID around
obj.params['X-VOBJ-ORIGINAL-TZID'] = [obj.params['TZID']]
del obj.params['TZID']
return obj
@classmethod
def transformFromNative(cls, obj):
"""
Replace the datetime in obj.value with an ISO 8601 string.
"""
if obj.isNative:
obj.isNative = False
tzid = TimezoneComponent.registerTzinfo(obj.value.tzinfo)
obj.value = dateTimeToString(obj.value, cls.forceUTC)
if not cls.forceUTC and tzid is not None:
obj.tzid_param = tzid
if obj.params.get('X-VOBJ-ORIGINAL-TZID'):
if not hasattr(obj, 'tzid_param'):
obj.tzid_param = obj.x_vobj_original_tzid_param
del obj.params['X-VOBJ-ORIGINAL-TZID']
return obj
class UTCDateTimeBehavior(DateTimeBehavior):
"""
A value which must be specified in UTC.
"""
forceUTC = True
class DateOrDateTimeBehavior(behavior.Behavior):
"""
Parent Behavior for ContentLines containing one DATE or DATE-TIME.
"""
hasNative = True
@staticmethod
def transformToNative(obj):
"""
Turn obj.value into a date or datetime.
"""
if obj.isNative:
return obj
obj.isNative = True
if obj.value == '':
return obj
obj.value = obj.value
obj.value = parseDtstart(obj, allowSignatureMismatch=True)
if getattr(obj, 'value_param', 'DATE-TIME').upper() == 'DATE-TIME':
if hasattr(obj, 'tzid_param'):
# Keep a copy of the original TZID around
obj.params['X-VOBJ-ORIGINAL-TZID'] = [obj.tzid_param]
del obj.tzid_param
return obj
@staticmethod
def transformFromNative(obj):
"""
Replace the date or datetime in obj.value with an ISO 8601 string.
"""
if type(obj.value) == datetime.date:
obj.isNative = False
obj.value_param = 'DATE'
obj.value = dateToString(obj.value)
return obj
else:
return DateTimeBehavior.transformFromNative(obj)
class MultiDateBehavior(behavior.Behavior):
"""
Parent Behavior for ContentLines containing one or more DATE, DATE-TIME, or
PERIOD.
"""
hasNative = True
@staticmethod
def transformToNative(obj):
"""
Turn obj.value into a list of dates, datetimes, or
(datetime, timedelta) tuples.
"""
if obj.isNative:
return obj
obj.isNative = True
if obj.value == '':
obj.value = []
return obj
tzinfo = getTzid(getattr(obj, 'tzid_param', None))
valueParam = getattr(obj, 'value_param', "DATE-TIME").upper()
valTexts = obj.value.split(",")
if valueParam == "DATE":
obj.value = [stringToDate(x) for x in valTexts]
elif valueParam == "DATE-TIME":
obj.value = [stringToDateTime(x, tzinfo) for x in valTexts]
elif valueParam == "PERIOD":
obj.value = [stringToPeriod(x, tzinfo) for x in valTexts]
return obj
@staticmethod
def transformFromNative(obj):
"""
Replace the date, datetime or period tuples in obj.value with
appropriate strings.
"""
if obj.value and type(obj.value[0]) == datetime.date:
obj.isNative = False
obj.value_param = 'DATE'
obj.value = ','.join([dateToString(val) for val in obj.value])
return obj
# Fixme: handle PERIOD case
else:
if obj.isNative:
obj.isNative = False
transformed = []
tzid = None
for val in obj.value:
if tzid is None and type(val) == datetime.datetime:
tzid = TimezoneComponent.registerTzinfo(val.tzinfo)
if tzid is not None:
obj.tzid_param = tzid
transformed.append(dateTimeToString(val))
obj.value = ','.join(transformed)
return obj
class MultiTextBehavior(behavior.Behavior):
"""
Provide backslash escape encoding/decoding of each of several values.
After transformation, value is a list of strings.
"""
listSeparator = ","
@classmethod
def decode(cls, line):
"""
Remove backslash escaping from line.value, then split on commas.
"""
if line.encoded:
line.value = stringToTextValues(line.value,
listSeparator=cls.listSeparator)
line.encoded = False
@classmethod
def encode(cls, line):
"""
Backslash escape line.value.
"""
if not line.encoded:
line.value = cls.listSeparator.join(backslashEscape(val)
for val in line.value)
line.encoded = True
class SemicolonMultiTextBehavior(MultiTextBehavior):
listSeparator = ";"
# ------------------------ Registered Behavior subclasses ----------------------
class VCalendar2_0(VCalendarComponentBehavior):
"""
vCalendar 2.0 behavior. With added VAVAILABILITY support.
"""
name = 'VCALENDAR'
description = 'vCalendar 2.0, also known as iCalendar.'
versionString = '2.0'
sortFirst = ('version', 'calscale', 'method', 'prodid', 'vtimezone')
knownChildren = {
'CALSCALE': (0, 1, None), # min, max, behaviorRegistry id
'METHOD': (0, 1, None),
'VERSION': (0, 1, None), # required, but auto-generated
'PRODID': (1, 1, None),
'VTIMEZONE': (0, None, None),
'VEVENT': (0, None, None),
'VTODO': (0, None, None),
'VJOURNAL': (0, None, None),
'VFREEBUSY': (0, None, None),
'VAVAILABILITY': (0, None, None),
}
@classmethod
def generateImplicitParameters(cls, obj):
"""
Create PRODID, VERSION and VTIMEZONEs if needed.
VTIMEZONEs will need to exist whenever TZID parameters exist or when
datetimes with tzinfo exist.
"""
for comp in obj.components():
if comp.behavior is not None:
comp.behavior.generateImplicitParameters(comp)
if not hasattr(obj, 'prodid'):
obj.add(ContentLine('PRODID', [], PRODID))
if not hasattr(obj, 'version'):
obj.add(ContentLine('VERSION', [], cls.versionString))
tzidsUsed = {}
def findTzids(obj, table):
if isinstance(obj, ContentLine) and (obj.behavior is None or
not obj.behavior.forceUTC):
if getattr(obj, 'tzid_param', None):
table[obj.tzid_param] = 1
else:
if type(obj.value) == list:
for item in obj.value:
tzinfo = getattr(obj.value, 'tzinfo', None)
tzid = TimezoneComponent.registerTzinfo(tzinfo)
if tzid:
table[tzid] = 1
else:
tzinfo = getattr(obj.value, 'tzinfo', None)
tzid = TimezoneComponent.registerTzinfo(tzinfo)
if tzid:
table[tzid] = 1
for child in obj.getChildren():
if obj.name != 'VTIMEZONE':
findTzids(child, table)
findTzids(obj, tzidsUsed)
oldtzids = [toUnicode(x.tzid.value) for x in getattr(obj, 'vtimezone_list', [])]
for tzid in tzidsUsed.keys():
tzid = toUnicode(tzid)
if tzid != u'UTC' and tzid not in oldtzids:
obj.add(TimezoneComponent(tzinfo=getTzid(tzid)))
@classmethod
def serialize(cls, obj, buf, lineLength, validate=True):
"""
Set implicit parameters, do encoding, return unicode string.
If validate is True, raise VObjectError if the line doesn't validate
after implicit parameters are generated.
Default is to call base.defaultSerialize.
"""
cls.generateImplicitParameters(obj)
if validate:
cls.validate(obj, raiseException=True)
if obj.isNative:
transformed = obj.transformFromNative()
undoTransform = True
else:
transformed = obj
undoTransform = False
out = None
outbuf = buf or six.StringIO()
if obj.group is None:
groupString = ''
else:
groupString = obj.group + '.'
if obj.useBegin:
foldOneLine(outbuf, "{0}BEGIN:{1}".format(groupString, obj.name),
lineLength)
try:
first_props = [s for s in cls.sortFirst if s in obj.contents \
and not isinstance(obj.contents[s][0], Component)]
first_components = [s for s in cls.sortFirst if s in obj.contents \
and isinstance(obj.contents[s][0], Component)]
except Exception:
first_props = first_components = []
# first_components = []
prop_keys = sorted(list(k for k in obj.contents.keys() if k not in first_props \
and not isinstance(obj.contents[k][0], Component)))
comp_keys = sorted(list(k for k in obj.contents.keys() if k not in first_components \
and isinstance(obj.contents[k][0], Component)))
sorted_keys = first_props + prop_keys + first_components + comp_keys
children = [o for k in sorted_keys for o in obj.contents[k]]
for child in children:
# validate is recursive, we only need to validate once
child.serialize(outbuf, lineLength, validate=False)
if obj.useBegin:
foldOneLine(outbuf, "{0}END:{1}".format(groupString, obj.name),
lineLength)
out = buf or outbuf.getvalue()
if undoTransform:
obj.transformToNative()
return out
registerBehavior(VCalendar2_0)
class VTimezone(VCalendarComponentBehavior):
"""
Timezone behavior.
"""
name = 'VTIMEZONE'
hasNative = True
description = 'A grouping of component properties that defines a time zone.'
sortFirst = ('tzid', 'last-modified', 'tzurl', 'standard', 'daylight')
knownChildren = {
'TZID': (1, 1, None), # min, max, behaviorRegistry id
'LAST-MODIFIED': (0, 1, None),
'TZURL': (0, 1, None),
'STANDARD': (0, None, None), # NOTE: One of Standard or
'DAYLIGHT': (0, None, None) # Daylight must appear
}
@classmethod
def validate(cls, obj, raiseException, *args):
if not hasattr(obj, 'tzid') or obj.tzid.value is None:
if raiseException:
m = "VTIMEZONE components must contain a valid TZID"
raise ValidateError(m)
return False
if 'standard' in obj.contents or 'daylight' in obj.contents:
return super(VTimezone, cls).validate(obj, raiseException, *args)
else:
if raiseException:
m = "VTIMEZONE components must contain a STANDARD or a DAYLIGHT\
component"
raise ValidateError(m)
return False
@staticmethod
def transformToNative(obj):
if not obj.isNative:
object.__setattr__(obj, '__class__', TimezoneComponent)
obj.isNative = True
obj.registerTzinfo(obj.tzinfo)
return obj
@staticmethod
def transformFromNative(obj):
return obj
registerBehavior(VTimezone)
class TZID(behavior.Behavior):
"""
Don't use TextBehavior for TZID.
RFC2445 only allows TZID lines to be paramtext, so they shouldn't need any
encoding or decoding. Unfortunately, some Microsoft products use commas
in TZIDs which should NOT be treated as a multi-valued text property, nor
do we want to escape them. Leaving them alone works for Microsoft's breakage,
and doesn't affect compliant iCalendar streams.
"""
registerBehavior(TZID)
class DaylightOrStandard(VCalendarComponentBehavior):
hasNative = False
knownChildren = {'DTSTART': (1, 1, None), # min, max, behaviorRegistry id
'RRULE': (0, 1, None)}
registerBehavior(DaylightOrStandard, 'STANDARD')
registerBehavior(DaylightOrStandard, 'DAYLIGHT')
class VEvent(RecurringBehavior):
"""
Event behavior.
"""
name = 'VEVENT'
sortFirst = ('uid', 'recurrence-id', 'dtstart', 'duration', 'dtend')
description = 'A grouping of component properties, and possibly including \
"VALARM" calendar components, that represents a scheduled \
amount of time on a calendar.'
knownChildren = {
'DTSTART': (0, 1, None), # min, max, behaviorRegistry id
'CLASS': (0, 1, None),
'CREATED': (0, 1, None),
'DESCRIPTION': (0, 1, None),
'GEO': (0, 1, None),
'LAST-MODIFIED': (0, 1, None),
'LOCATION': (0, 1, None),
'ORGANIZER': (0, 1, None),
'PRIORITY': (0, 1, None),
'DTSTAMP': (1, 1, None), # required
'SEQUENCE': (0, 1, None),
'STATUS': (0, 1, None),
'SUMMARY': (0, 1, None),
'TRANSP': (0, 1, None),
'UID': (1, 1, None),
'URL': (0, 1, None),
'RECURRENCE-ID': (0, 1, None),
'DTEND': (0, 1, None), # NOTE: Only one of DtEnd or
'DURATION': (0, 1, None), # Duration can appear
'ATTACH': (0, None, None),
'ATTENDEE': (0, None, None),
'CATEGORIES': (0, None, None),
'COMMENT': (0, None, None),
'CONTACT': (0, None, None),
'EXDATE': (0, None, None),
'EXRULE': (0, None, None),
'REQUEST-STATUS': (0, None, None),
'RELATED-TO': (0, None, None),
'RESOURCES': (0, None, None),
'RDATE': (0, None, None),
'RRULE': (0, None, None),
'VALARM': (0, None, None)
}
@classmethod
def validate(cls, obj, raiseException, *args):
if 'dtend' in obj.contents and 'duration' in obj.contents:
if raiseException:
m = "VEVENT components cannot contain both DTEND and DURATION\
components"
raise ValidateError(m)
return False
else:
return super(VEvent, cls).validate(obj, raiseException, *args)
registerBehavior(VEvent)
class VTodo(RecurringBehavior):
"""
To-do behavior.
"""
name = 'VTODO'
description = 'A grouping of component properties and possibly "VALARM" \
calendar components that represent an action-item or \
assignment.'
knownChildren = {
'DTSTART': (0, 1, None), # min, max, behaviorRegistry id
'CLASS': (0, 1, None),
'COMPLETED': (0, 1, None),
'CREATED': (0, 1, None),
'DESCRIPTION': (0, 1, None),
'GEO': (0, 1, None),
'LAST-MODIFIED': (0, 1, None),
'LOCATION': (0, 1, None),
'ORGANIZER': (0, 1, None),
'PERCENT': (0, 1, None),
'PRIORITY': (0, 1, None),
'DTSTAMP': (1, 1, None),
'SEQUENCE': (0, 1, None),
'STATUS': (0, 1, None),
'SUMMARY': (0, 1, None),
'UID': (0, 1, None),
'URL': (0, 1, None),
'RECURRENCE-ID': (0, 1, None),
'DUE': (0, 1, None), # NOTE: Only one of Due or
'DURATION': (0, 1, None), # Duration can appear
'ATTACH': (0, None, None),
'ATTENDEE': (0, None, None),
'CATEGORIES': (0, None, None),
'COMMENT': (0, None, None),
'CONTACT': (0, None, None),
'EXDATE': (0, None, None),
'EXRULE': (0, None, None),
'REQUEST-STATUS': (0, None, None),
'RELATED-TO': (0, None, None),
'RESOURCES': (0, None, None),
'RDATE': (0, None, None),
'RRULE': (0, None, None),
'VALARM': (0, None, None)
}
@classmethod
def validate(cls, obj, raiseException, *args):
if 'due' in obj.contents and 'duration' in obj.contents:
if raiseException:
m = "VTODO components cannot contain both DUE and DURATION\
components"
raise ValidateError(m)
return False
else:
return super(VTodo, cls).validate(obj, raiseException, *args)
registerBehavior(VTodo)
class VJournal(RecurringBehavior):
"""
Journal entry behavior.
"""
name = 'VJOURNAL'
knownChildren = {
'DTSTART': (0, 1, None), # min, max, behaviorRegistry id
'CLASS': (0, 1, None),
'CREATED': (0, 1, None),
'DESCRIPTION': (0, 1, None),
'LAST-MODIFIED': (0, 1, None),
'ORGANIZER': (0, 1, None),
'DTSTAMP': (1, 1, None),
'SEQUENCE': (0, 1, None),
'STATUS': (0, 1, None),
'SUMMARY': (0, 1, None),
'UID': (0, 1, None),
'URL': (0, 1, None),
'RECURRENCE-ID': (0, 1, None),
'ATTACH': (0, None, None),
'ATTENDEE': (0, None, None),
'CATEGORIES': (0, None, None),
'COMMENT': (0, None, None),
'CONTACT': (0, None, None),
'EXDATE': (0, None, None),
'EXRULE': (0, None, None),
'REQUEST-STATUS': (0, None, None),
'RELATED-TO': (0, None, None),
'RDATE': (0, None, None),
'RRULE': (0, None, None)
}
registerBehavior(VJournal)
class VFreeBusy(VCalendarComponentBehavior):
"""
Free/busy state behavior.
"""
name = 'VFREEBUSY'
description = 'A grouping of component properties that describe either a \
request for free/busy time, describe a response to a request \
for free/busy time or describe a published set of busy time.'
sortFirst = ('uid', 'dtstart', 'duration', 'dtend')
knownChildren = {
'DTSTART': (0, 1, None), # min, max, behaviorRegistry id
'CONTACT': (0, 1, None),
'DTEND': (0, 1, None),
'DURATION': (0, 1, None),
'ORGANIZER': (0, 1, None),
'DTSTAMP': (1, 1, None),
'UID': (0, 1, None),
'URL': (0, 1, None),
'ATTENDEE': (0, None, None),
'COMMENT': (0, None, None),
'FREEBUSY': (0, None, None),
'REQUEST-STATUS': (0, None, None)
}
registerBehavior(VFreeBusy)
class VAlarm(VCalendarComponentBehavior):
"""
Alarm behavior.
"""
name = 'VALARM'
description = 'Alarms describe when and how to provide alerts about events \
and to-dos.'
knownChildren = {
'ACTION': (1, 1, None), # min, max, behaviorRegistry id
'TRIGGER': (1, 1, None),
'DURATION': (0, 1, None),
'REPEAT': (0, 1, None),
'DESCRIPTION': (0, 1, None)
}
@staticmethod
def generateImplicitParameters(obj):
"""
Create default ACTION and TRIGGER if they're not set.
"""
try:
obj.action
except AttributeError:
obj.add('action').value = 'AUDIO'
try:
obj.trigger
except AttributeError:
obj.add('trigger').value = datetime.timedelta(0)
@classmethod
def validate(cls, obj, raiseException, *args):
"""
# TODO
if obj.contents.has_key('dtend') and obj.contents.has_key('duration'):
if raiseException:
m = "VEVENT components cannot contain both DTEND and DURATION\
components"
raise ValidateError(m)
return False
else:
return super(VEvent, cls).validate(obj, raiseException, *args)
"""
return True
registerBehavior(VAlarm)
class VAvailability(VCalendarComponentBehavior):
"""
Availability state behavior.
Used to represent user's available time slots.
"""
name = 'VAVAILABILITY'
description = 'A component used to represent a user\'s available time slots.'
sortFirst = ('uid', 'dtstart', 'duration', 'dtend')
knownChildren = {
'UID': (1, 1, None), # min, max, behaviorRegistry id
'DTSTAMP': (1, 1, None),
'BUSYTYPE': (0, 1, None),
'CREATED': (0, 1, None),
'DTSTART': (0, 1, None),
'LAST-MODIFIED': (0, 1, None),
'ORGANIZER': (0, 1, None),
'SEQUENCE': (0, 1, None),
'SUMMARY': (0, 1, None),
'URL': (0, 1, None),
'DTEND': (0, 1, None),
'DURATION': (0, 1, None),
'CATEGORIES': (0, None, None),
'COMMENT': (0, None, None),
'CONTACT': (0, None, None),
'AVAILABLE': (0, None, None),
}
@classmethod
def validate(cls, obj, raiseException, *args):
if 'dtend' in obj.contents and 'duration' in obj.contents:
if raiseException:
m = "VAVAILABILITY components cannot contain both DTEND and DURATION components"
raise ValidateError(m)
return False
else:
return super(VAvailability, cls).validate(obj, raiseException, *args)
registerBehavior(VAvailability)
class Available(RecurringBehavior):
"""
Event behavior.
"""
name = 'AVAILABLE'
sortFirst = ('uid', 'recurrence-id', 'dtstart', 'duration', 'dtend')
description = 'Defines a period of time in which a user is normally available.'
knownChildren = {
'DTSTAMP': (1, 1, None), # min, max, behaviorRegistry id
'DTSTART': (1, 1, None),
'UID': (1, 1, None),
'DTEND': (0, 1, None), # NOTE: One of DtEnd or
'DURATION': (0, 1, None), # Duration must appear, but not both
'CREATED': (0, 1, None),
'LAST-MODIFIED': (0, 1, None),
'RECURRENCE-ID': (0, 1, None),
'RRULE': (0, 1, None),
'SUMMARY': (0, 1, None),
'CATEGORIES': (0, None, None),
'COMMENT': (0, None, None),
'CONTACT': (0, None, None),
'EXDATE': (0, None, None),
'RDATE': (0, None, None),
}
@classmethod
def validate(cls, obj, raiseException, *args):
has_dtend = 'dtend' in obj.contents
has_duration = 'duration' in obj.contents
if has_dtend and has_duration:
if raiseException:
m = "AVAILABLE components cannot contain both DTEND and DURATION\
properties"
raise ValidateError(m)
return False
elif not (has_dtend or has_duration):
if raiseException:
m = "AVAILABLE components must contain one of DTEND or DURATION\
properties"
raise ValidateError(m)
return False
else:
return super(Available, cls).validate(obj, raiseException, *args)
registerBehavior(Available)
class Duration(behavior.Behavior):
"""
Behavior for Duration ContentLines. Transform to datetime.timedelta.
"""
name = 'DURATION'
hasNative = True
@staticmethod
def transformToNative(obj):
"""
Turn obj.value into a datetime.timedelta.
"""
if obj.isNative:
return obj
obj.isNative = True
obj.value = obj.value
if obj.value == '':
return obj
else:
deltalist = stringToDurations(obj.value)
# When can DURATION have multiple durations? For now:
if len(deltalist) == 1:
obj.value = deltalist[0]
return obj
else:
raise ParseError("DURATION must have a single duration string.")
@staticmethod
def transformFromNative(obj):
"""
Replace the datetime.timedelta in obj.value with an RFC2445 string.
"""
if not obj.isNative:
return obj
obj.isNative = False
obj.value = timedeltaToString(obj.value)
return obj
registerBehavior(Duration)
class Trigger(behavior.Behavior):
"""
DATE-TIME or DURATION
"""
name = 'TRIGGER'
description = 'This property specifies when an alarm will trigger.'
hasNative = True
forceUTC = True
@staticmethod
def transformToNative(obj):
"""
Turn obj.value into a timedelta or datetime.
"""
if obj.isNative:
return obj
value = getattr(obj, 'value_param', 'DURATION').upper()
if hasattr(obj, 'value_param'):
del obj.value_param
if obj.value == '':
obj.isNative = True
return obj
elif value == 'DURATION':
try:
return Duration.transformToNative(obj)
except ParseError:
logger.warning("TRIGGER not recognized as DURATION, trying "
"DATE-TIME, because iCal sometimes exports "
"DATE-TIMEs without setting VALUE=DATE-TIME")
try:
obj.isNative = False
dt = DateTimeBehavior.transformToNative(obj)
return dt
except:
msg = "TRIGGER with no VALUE not recognized as DURATION " \
"or as DATE-TIME"
raise ParseError(msg)
elif value == 'DATE-TIME':
# TRIGGERs with DATE-TIME values must be in UTC, we could validate
# that fact, for now we take it on faith.
return DateTimeBehavior.transformToNative(obj)
else:
raise ParseError("VALUE must be DURATION or DATE-TIME")
@staticmethod
def transformFromNative(obj):
if type(obj.value) == datetime.datetime:
obj.value_param = 'DATE-TIME'
return UTCDateTimeBehavior.transformFromNative(obj)
elif type(obj.value) == datetime.timedelta:
return Duration.transformFromNative(obj)
else:
raise NativeError("Native TRIGGER values must be timedelta or "
"datetime")
registerBehavior(Trigger)
class PeriodBehavior(behavior.Behavior):
"""
A list of (date-time, timedelta) tuples.
"""
hasNative = True
@staticmethod
def transformToNative(obj):
"""
Convert comma separated periods into tuples.
"""
if obj.isNative:
return obj
obj.isNative = True
if obj.value == '':
obj.value = []
return obj
tzinfo = getTzid(getattr(obj, 'tzid_param', None))
obj.value = [stringToPeriod(x, tzinfo) for x in obj.value.split(",")]
return obj
@classmethod
def transformFromNative(cls, obj):
"""
Convert the list of tuples in obj.value to strings.
"""
if obj.isNative:
obj.isNative = False
transformed = []
for tup in obj.value:
transformed.append(periodToString(tup, cls.forceUTC))
if len(transformed) > 0:
tzid = TimezoneComponent.registerTzinfo(tup[0].tzinfo)
if not cls.forceUTC and tzid is not None:
obj.tzid_param = tzid
obj.value = ','.join(transformed)
return obj
class FreeBusy(PeriodBehavior):
"""
Free or busy period of time, must be specified in UTC.
"""
name = 'FREEBUSY'
forceUTC = True
registerBehavior(FreeBusy, 'FREEBUSY')
class RRule(behavior.Behavior):
"""
Dummy behavior to avoid having RRULEs being treated as text lines (and thus
having semi-colons inaccurately escaped).
"""
registerBehavior(RRule, 'RRULE')
registerBehavior(RRule, 'EXRULE')
# ------------------------ Registration of common classes ----------------------
utcDateTimeList = ['LAST-MODIFIED', 'CREATED', 'COMPLETED', 'DTSTAMP']
list(map(lambda x: registerBehavior(UTCDateTimeBehavior, x), utcDateTimeList))
dateTimeOrDateList = ['DTEND', 'DTSTART', 'DUE', 'RECURRENCE-ID']
list(map(lambda x: registerBehavior(DateOrDateTimeBehavior, x),
dateTimeOrDateList))
registerBehavior(MultiDateBehavior, 'RDATE')
registerBehavior(MultiDateBehavior, 'EXDATE')
textList = ['CALSCALE', 'METHOD', 'PRODID', 'CLASS', 'COMMENT', 'DESCRIPTION',
'LOCATION', 'STATUS', 'SUMMARY', 'TRANSP', 'CONTACT', 'RELATED-TO',
'UID', 'ACTION', 'BUSYTYPE']
list(map(lambda x: registerBehavior(TextBehavior, x), textList))
list(map(lambda x: registerBehavior(MultiTextBehavior, x), ['CATEGORIES',
'RESOURCES']))
registerBehavior(SemicolonMultiTextBehavior, 'REQUEST-STATUS')
# ------------------------ Serializing helper functions ------------------------
def numToDigits(num, places):
"""
Helper, for converting numbers to textual digits.
"""
s = str(num)
if len(s) < places:
return ("0" * (places - len(s))) + s
elif len(s) > places:
return s[len(s)-places:]
else:
return s
def timedeltaToString(delta):
"""
Convert timedelta to an ical DURATION.
"""
if delta.days == 0:
sign = 1
else:
sign = delta.days / abs(delta.days)
delta = abs(delta)
days = delta.days
hours = int(delta.seconds / 3600)
minutes = int((delta.seconds % 3600) / 60)
seconds = int(delta.seconds % 60)
output = ''
if sign == -1:
output += '-'
output += 'P'
if days:
output += '{}D'.format(days)
if hours or minutes or seconds:
output += 'T'
elif not days: # Deal with zero duration
output += 'T0S'
if hours:
output += '{}H'.format(hours)
if minutes:
output += '{}M'.format(minutes)
if seconds:
output += '{}S'.format(seconds)
return output
def timeToString(dateOrDateTime):
"""
Wraps dateToString and dateTimeToString, returning the results
of either based on the type of the argument
"""
if hasattr(dateOrDateTime, 'hour'):
return dateTimeToString(dateOrDateTime)
return dateToString(dateOrDateTime)
def dateToString(date):
year = numToDigits(date.year, 4)
month = numToDigits(date.month, 2)
day = numToDigits(date.day, 2)
return year + month + day
def dateTimeToString(dateTime, convertToUTC=False):
"""
Ignore tzinfo unless convertToUTC. Output string.
"""
if dateTime.tzinfo and convertToUTC:
dateTime = dateTime.astimezone(utc)
datestr = "{0}{1}{2}T{3}{4}{5}".format(
numToDigits(dateTime.year, 4),
numToDigits(dateTime.month, 2),
numToDigits(dateTime.day, 2),
numToDigits(dateTime.hour, 2),
numToDigits(dateTime.minute, 2),
numToDigits(dateTime.second, 2),
)
if tzinfo_eq(dateTime.tzinfo, utc):
datestr += "Z"
return datestr
def deltaToOffset(delta):
absDelta = abs(delta)
hours = int(absDelta.seconds / 3600)
hoursString = numToDigits(hours, 2)
minutesString = '00'
if absDelta == delta:
signString = "+"
else:
signString = "-"
return signString + hoursString + minutesString
def periodToString(period, convertToUTC=False):
txtstart = dateTimeToString(period[0], convertToUTC)
if isinstance(period[1], datetime.timedelta):
txtend = timedeltaToString(period[1])
else:
txtend = dateTimeToString(period[1], convertToUTC)
return txtstart + "/" + txtend
# ----------------------- Parsing functions ------------------------------------
def isDuration(s):
s = s.upper()
return (s.find("P") != -1) and (s.find("P") < 2)
def stringToDate(s):
year = int(s[0:4])
month = int(s[4:6])
day = int(s[6:8])
return datetime.date(year, month, day)
def stringToDateTime(s, tzinfo=None):
"""
Returns datetime.datetime object.
"""
try:
year = int(s[0:4])
month = int(s[4:6])
day = int(s[6:8])
hour = int(s[9:11])
minute = int(s[11:13])
second = int(s[13:15])
if len(s) > 15:
if s[15] == 'Z':
tzinfo = getTzid('UTC')
except:
raise ParseError("'{0!s}' is not a valid DATE-TIME".format(s))
year = year and year or 2000
if tzinfo is not None and hasattr(tzinfo,'localize'): # PyTZ case
return tzinfo.localize(datetime.datetime(year, month, day, hour, minute, second))
return datetime.datetime(year, month, day, hour, minute, second, 0, tzinfo)
# DQUOTE included to work around iCal's penchant for backslash escaping it,
# although it isn't actually supposed to be escaped according to rfc2445 TEXT
escapableCharList = '\\;,Nn"'
def stringToTextValues(s, listSeparator=',', charList=None, strict=False):
"""
Returns list of strings.
"""
if charList is None:
charList = escapableCharList
def escapableChar(c):
return c in charList
def error(msg):
if strict:
raise ParseError(msg)
else:
logging.error(msg)
# vars which control state machine
charIterator = enumerate(s)
state = "read normal"
current = []
results = []
while True:
try:
charIndex, char = next(charIterator)
except:
char = "eof"
if state == "read normal":
if char == '\\':
state = "read escaped char"
elif char == listSeparator:
state = "read normal"
current = "".join(current)
results.append(current)
current = []
elif char == "eof":
state = "end"
else:
state = "read normal"
current.append(char)
elif state == "read escaped char":
if escapableChar(char):
state = "read normal"
if char in 'nN':
current.append('\n')
else:
current.append(char)
else:
state = "read normal"
# leave unrecognized escaped characters for later passes
current.append('\\' + char)
elif state == "end": # an end state
if len(current) or len(results) == 0:
current = "".join(current)
results.append(current)
return results
elif state == "error": # an end state
return results
else:
state = "error"
error("unknown state: '{0!s}' reached in {1!s}".format(state, s))
def stringToDurations(s, strict=False):
"""
Returns list of timedelta objects.
"""
def makeTimedelta(sign, week, day, hour, minute, sec):
if sign == "-":
sign = -1
else:
sign = 1
week = int(week)
day = int(day)
hour = int(hour)
minute = int(minute)
sec = int(sec)
return sign * datetime.timedelta(weeks=week, days=day, hours=hour,
minutes=minute, seconds=sec)
def error(msg):
if strict:
raise ParseError(msg)
else:
raise ParseError(msg)
# vars which control state machine
charIterator = enumerate(s)
state = "start"
durations = []
current = ""
sign = None
week = 0
day = 0
hour = 0
minute = 0
sec = 0
while True:
try:
charIndex, char = next(charIterator)
except:
char = "eof"
if state == "start":
if char == '+':
state = "start"
sign = char
elif char == '-':
state = "start"
sign = char
elif char.upper() == 'P':
state = "read field"
elif char == "eof":
state = "error"
error("got end-of-line while reading in duration: " + s)
elif char in string.digits:
state = "read field"
current = current + char # update this part when updating "read field"
else:
state = "error"
error("got unexpected character {0} reading in duration: {1}"
.format(char, s))
elif state == "read field":
if (char in string.digits):
state = "read field"
current = current + char # update part above when updating "read field"
elif char.upper() == 'T':
state = "read field"
elif char.upper() == 'W':
state = "read field"
week = current
current = ""
elif char.upper() == 'D':
state = "read field"
day = current
current = ""
elif char.upper() == 'H':
state = "read field"
hour = current
current = ""
elif char.upper() == 'M':
state = "read field"
minute = current
current = ""
elif char.upper() == 'S':
state = "read field"
sec = current
current = ""
elif char == ",":
state = "start"
durations.append(makeTimedelta(sign, week, day, hour, minute,
sec))
current = ""
sign = None
week = None
day = None
hour = None
minute = None
sec = None
elif char == "eof":
state = "end"
else:
state = "error"
error("got unexpected character reading in duration: " + s)
elif state == "end": # an end state
if (sign or week or day or hour or minute or sec):
durations.append(makeTimedelta(sign, week, day, hour, minute,
sec))
return durations
elif state == "error": # an end state
error("in error state")
return durations
else:
state = "error"
error("unknown state: '{0!s}' reached in {1!s}".format(state, s))
def parseDtstart(contentline, allowSignatureMismatch=False):
"""
Convert a contentline's value into a date or date-time.
A variety of clients don't serialize dates with the appropriate VALUE
parameter, so rather than failing on these (technically invalid) lines,
if allowSignatureMismatch is True, try to parse both varieties.
"""
tzinfo = getTzid(getattr(contentline, 'tzid_param', None))
valueParam = getattr(contentline, 'value_param', 'DATE-TIME').upper()
if valueParam == "DATE":
return stringToDate(contentline.value)
elif valueParam == "DATE-TIME":
try:
return stringToDateTime(contentline.value, tzinfo)
except:
if allowSignatureMismatch:
return stringToDate(contentline.value)
else:
raise
def stringToPeriod(s, tzinfo=None):
values = s.split("/")
start = stringToDateTime(values[0], tzinfo)
valEnd = values[1]
if isDuration(valEnd): # period-start = date-time "/" dur-value
delta = stringToDurations(valEnd)[0]
return (start, delta)
else:
return (start, stringToDateTime(valEnd, tzinfo))
def getTransition(transitionTo, year, tzinfo):
"""
Return the datetime of the transition to/from DST, or None.
"""
def firstTransition(iterDates, test):
"""
Return the last date not matching test, or None if all tests matched.
"""
success = None
for dt in iterDates:
if not test(dt):
success = dt
else:
if success is not None:
return success
return success # may be None
def generateDates(year, month=None, day=None):
"""
Iterate over possible dates with unspecified values.
"""
months = range(1, 13)
days = range(1, 32)
hours = range(0, 24)
if month is None:
for month in months:
yield datetime.datetime(year, month, 1)
elif day is None:
for day in days:
try:
yield datetime.datetime(year, month, day)
except ValueError:
pass
else:
for hour in hours:
yield datetime.datetime(year, month, day, hour)
assert transitionTo in ('daylight', 'standard')
if transitionTo == 'daylight':
def test(dt):
try:
return tzinfo.dst(dt) != zeroDelta
except pytz.NonExistentTimeError:
return True # entering daylight time
except pytz.AmbiguousTimeError:
return False # entering standard time
elif transitionTo == 'standard':
def test(dt):
try:
return tzinfo.dst(dt) == zeroDelta
except pytz.NonExistentTimeError:
return False # entering daylight time
except pytz.AmbiguousTimeError:
return True # entering standard time
newyear = datetime.datetime(year, 1, 1)
monthDt = firstTransition(generateDates(year), test)
if monthDt is None:
return newyear
elif monthDt.month == 12:
return None
else:
# there was a good transition somewhere in a non-December month
month = monthDt.month
day = firstTransition(generateDates(year, month), test).day
uncorrected = firstTransition(generateDates(year, month, day), test)
if transitionTo == 'standard':
# assuming tzinfo.dst returns a new offset for the first
# possible hour, we need to add one hour for the offset change
# and another hour because firstTransition returns the hour
# before the transition
return uncorrected + datetime.timedelta(hours=2)
else:
return uncorrected + datetime.timedelta(hours=1)
def tzinfo_eq(tzinfo1, tzinfo2, startYear=2000, endYear=2020):
"""
Compare offsets and DST transitions from startYear to endYear.
"""
if tzinfo1 == tzinfo2:
return True
elif tzinfo1 is None or tzinfo2 is None:
return False
def dt_test(dt):
if dt is None:
return True
return tzinfo1.utcoffset(dt) == tzinfo2.utcoffset(dt)
if not dt_test(datetime.datetime(startYear, 1, 1)):
return False
for year in range(startYear, endYear):
for transitionTo in 'daylight', 'standard':
t1 = getTransition(transitionTo, year, tzinfo1)
t2 = getTransition(transitionTo, year, tzinfo2)
if t1 != t2 or not dt_test(t1):
return False
return True
# ------------------- Testing and running functions ----------------------------
if __name__ == '__main__':
import tests
tests._test()
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