imip-agent

Annotated imipweb/data.py

525:b447338c07b8
524:65092bd5fd29
517:123e849c3982
2015-05-15 Paul Boddie file changeset files shortlog Added convenience methods for object copying, property access and removal, and time zone identifier acquisition.
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#!/usr/bin/env python
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"""
 
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Web interface data abstractions.
 
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Copyright (C) 2014, 2015 Paul Boddie <paul@boddie.org.uk>
 
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This program is free software; you can redistribute it and/or modify it under
 
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the terms of the GNU General Public License as published by the Free Software
 
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Foundation; either version 3 of the License, or (at your option) any later
 
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version.
 
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This program is distributed in the hope that it will be useful, but WITHOUT
 
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 
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FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 
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details.
 
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You should have received a copy of the GNU General Public License along with
 
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this program.  If not, see <http://www.gnu.org/licenses/>.
 
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"""
 
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from datetime import datetime, timedelta
 
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from imiptools.dates import format_datetime, get_datetime, get_start_of_day, to_date
 
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from imiptools.period import Period
 
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class PeriodError(Exception):
 
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    pass
 
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class EventPeriod(Period):
 
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    """
 
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    A simple period plus attribute details, compatible with RecurringPeriod, and
 
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    intended to represent information obtained from an iCalendar resource.
 
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    """
 
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    def __init__(self, start, end, start_attr=None, end_attr=None, form_start=None, form_end=None, origin=None):
 
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        Period.__init__(self, start, end)
 
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        self.start_attr = start_attr
 
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        self.end_attr = end_attr
 
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        self.form_start = form_start
 
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        self.form_end = form_end
 
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        self.origin = origin
 
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    def as_tuple(self):
 
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        return self.start, self.end, self.start_attr, self.end_attr, self.form_start, self.form_end, self.origin
 
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    def __repr__(self):
 
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        return "EventPeriod(%r, %r, %r, %r, %r, %r, %r)" % self.as_tuple()
 
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    def as_event_period(self):
 
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        return self
 
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    # Period data methods.
 
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    def get_start(self):
 
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        return self.start
 
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    def get_end(self):
 
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        return end_date_from_calendar(self.end)
 
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    # Form data compatibility methods.
 
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    def get_form_start(self):
 
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        if not self.form_start:
 
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            self.form_start = self.get_form_date(self.get_start(), self.start_attr)
 
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        return self.form_start
 
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    def get_form_end(self):
 
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        if not self.form_end:
 
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            self.form_end = self.get_form_date(self.get_end(), self.end_attr)
 
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        return self.form_end
 
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    def as_form_period(self):
 
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        return FormPeriod(
 
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            self.get_form_start(),
 
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            self.get_form_end(),
 
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            isinstance(self.end, datetime) or self.get_start() != self.get_end(),
 
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            isinstance(self.start, datetime) or isinstance(self.end, datetime)
 
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            )
 
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    def get_form_date(self, dt, attr=None):
 
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        return FormDate(
 
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            format_datetime(to_date(dt)),
 
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            isinstance(dt, datetime) and str(dt.hour) or None,
 
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            isinstance(dt, datetime) and str(dt.minute) or None,
 
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            isinstance(dt, datetime) and str(dt.second) or None,
 
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            attr and attr.get("TZID") or None,
 
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            dt, attr
 
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            )
 
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class FormPeriod:
 
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    "A period whose information originates from a form."
 
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    def __init__(self, start, end, end_enabled=True, times_enabled=True, origin=None):
 
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        self.start = start
 
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        self.end = end
 
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        self.end_enabled = end_enabled
 
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        self.times_enabled = times_enabled
 
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        self.origin = origin
 
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    def as_tuple(self):
 
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        return self.start, self.end, self.end_enabled, self.times_enabled, self.origin
 
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    def __repr__(self):
 
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        return "FormPeriod(%r, %r, %r, %r, %r)" % self.as_tuple()
 
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    def _get_start(self):
 
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        t = self.start.as_datetime_item(self.times_enabled)
 
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        if t:
 
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            return t
 
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        else:
 
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            return None
 
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    def _get_end(self, adjust=False):
 
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        # Handle specified end datetimes.
 
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        if self.end_enabled:
 
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            t = self.end.as_datetime_item(self.times_enabled)
 
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            if t:
 
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                dtend, dtend_attr = t
 
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                dtend = adjust and end_date_to_calendar(dtend) or dtend
 
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            else:
 
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                return None
 
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        # Otherwise, treat the end date as the start date. Datetimes are
 
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        # handled by making the event occupy the rest of the day.
 
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        else:
 
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            t = self._get_start()
 
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            if t:
 
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                dtstart, dtstart_attr = t
 
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                dtend = dtstart + timedelta(1)
 
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                dtend_attr = dtstart_attr
 
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                if isinstance(dtstart, datetime):
 
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                    dtend = get_start_of_day(dtend, dtend_attr["TZID"])
 
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            else:
 
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                return None
 
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        return dtend, dtend_attr
 
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    def as_event_period(self, index=None):
 
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        t = self._get_start()
 
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        if t:
 
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            dtstart, dtstart_attr = t
 
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        else:
 
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            raise PeriodError(*[index is not None and ("dtstart", index) or "dtstart"])
 
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        t = self._get_end(adjust=True)
 
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        if t:
 
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            dtend, dtend_attr = t
 
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        else:
 
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            raise PeriodError(*[index is not None and ("dtend", index) or "dtend"])
 
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        if dtstart > dtend:
 
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            raise PeriodError(*[
 
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                index is not None and ("dtstart", index) or "dtstart",
 
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                index is not None and ("dtend", index) or "dtend"
 
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                ])
 
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        return EventPeriod(dtstart, dtend, dtstart_attr, dtend_attr, self.start, self.end, self.origin)
 
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    # Period data methods.
 
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    def get_start(self):
 
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        t = self._get_start()
 
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        if t:
 
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            dtstart, dtstart_attr = t
 
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            return dtstart
 
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        else:
 
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            return None
 
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    def get_end(self):
 
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        t = self._get_end()
 
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        if t:
 
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            dtend, dtend_attr = t
 
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            return dtend
 
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        else:
 
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            return None
 
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    # Form data methods.
 
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    def get_form_start(self):
 
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        return self.start
 
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    def get_form_end(self):
 
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        return self.end
 
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    def as_form_period(self):
 
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        return self
 
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class FormDate:
 
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    "Date information originating from form information."
 
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    def __init__(self, date=None, hour=None, minute=None, second=None, tzid=None, dt=None, attr=None):
 
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        self.date = date
 
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        self.hour = hour
 
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        self.minute = minute
 
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        self.second = second
 
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        self.tzid = tzid
 
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        self.dt = dt
 
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        self.attr = attr
 
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    def as_tuple(self):
 
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        return self.date, self.hour, self.minute, self.second, self.tzid, self.dt, self.attr
 
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    def __repr__(self):
 
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        return "FormDate(%r, %r, %r, %r, %r, %r, %r)" % self.as_tuple()
 
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    def get_component(self, value):
 
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        return (value or "").rjust(2, "0")[:2]
 
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    def get_hour(self):
 
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        return self.get_component(self.hour)
 
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    def get_minute(self):
 
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        return self.get_component(self.minute)
 
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    def get_second(self):
 
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        return self.get_component(self.second)
 
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    def get_date_string(self):
 
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        return self.date or ""
 
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    def get_datetime_string(self):
 
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        if not self.date:
 
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            return ""
 
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        hour = self.hour; minute = self.minute; second = self.second
 
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        if hour or minute or second:
 
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            time = "T%s%s%s" % tuple(map(self.get_component, (hour, minute, second)))
 
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        else:
 
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            time = ""
 
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        return "%s%s" % (self.date, time)
 
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    def get_tzid(self):
 
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        return self.tzid
 
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    def as_datetime_item(self, with_time=True):
 
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        """
 
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        Return a (datetime, attr) tuple for the datetime information provided by
 
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        this object, or None if the fields cannot be used to construct a
 
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        datetime object.
 
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        """
 
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        # Return any original datetime details.
 
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        if self.dt:
 
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            return self.dt, self.attr
 
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        # Otherwise, construct a datetime and attributes.
 
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        if not self.date:
 
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            return None
 
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        elif with_time:
 
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            attr = {"TZID" : self.get_tzid(), "VALUE" : "DATE-TIME"}
 
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            dt = get_datetime(self.get_datetime_string(), attr)
 
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        else:
 
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            dt = None
 
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        # Interpret incomplete datetimes as dates.
 
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        if not dt:
 
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            attr = {"VALUE" : "DATE"}
 
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            dt = get_datetime(self.get_date_string(), attr)
 
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        if dt:
 
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            return dt, attr
 
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        return None
 
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def end_date_to_calendar(dt):
 
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    """
 
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    Change end dates to refer to the iCalendar "next day" dates, not the actual
 
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    dates.
 
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    """
 
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    if not isinstance(dt, datetime):
 
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        return dt + timedelta(1)
 
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    else:
 
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        return dt
 
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def end_date_from_calendar(dt):
 
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    """
 
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    Change end dates to refer to the actual dates, not the iCalendar "next day"
 
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    dates.
 
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    """
 
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    if not isinstance(dt, datetime):
 
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        return dt - timedelta(1)
 
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    else:
 
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        return dt
 
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def event_period_from_period(period):
 
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    if isinstance(period, EventPeriod):
 
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        return period
 
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    elif isinstance(period, FormPeriod):
 
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        return period.as_event_period()
 
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    else:
 
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        return EventPeriod(period.start, period.end, period.start_attr, period.end_attr, origin=period.origin)
 
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def form_period_from_period(period):
 
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    if isinstance(period, EventPeriod):
 
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        return period.as_form_period()
 
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    elif isinstance(period, FormPeriod):
 
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        return period
 
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    else:
 
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        return event_period_from_period(period).as_form_period()
 
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# vim: tabstop=4 expandtab shiftwidth=4