Fixed #18323 -- Refactored date arithmetic (20e69736) · Commits · Dom Sekotill / django

django/views/generic/dates.py

+139 −63

Original line number	Diff line number	Diff line
		@@ -23,7 +23,9 @@ class YearMixin(object):
		return self.year_format

		def get_year(self):
		"Return the year for which this view should display data"
		"""
		Return the year for which this view should display data.
		"""
		year = self.year
		if year is None:
		try:
		@@ -35,6 +37,20 @@ class YearMixin(object):
		raise Http404(_(u"No year specified"))
		return year

		def _get_next_year(self, date):
		"""
		Return the start date of the next interval.

		The interval is defined by start date <= item date < next start date.
		"""
		return date.replace(year=date.year + 1, month=1, day=1)

		def _get_current_year(self, date):
		"""
		Return the start date of the current interval.
		"""
		return date.replace(month=1, day=1)


		class MonthMixin(object):
		month_format = '%b'
		@@ -48,7 +64,9 @@ class MonthMixin(object):
		return self.month_format

		def get_month(self):
		"Return the month for which this view should display data"
		"""
		Return the month for which this view should display data.
		"""
		month = self.month
		if month is None:
		try:
		@@ -64,20 +82,30 @@ class MonthMixin(object):
		"""
		Get the next valid month.
		"""
		# next must be the first day of the next month.
		if date.month == 12:
		next = date.replace(year=date.year + 1, month=1, day=1)
		else:
		next = date.replace(month=date.month + 1, day=1)
		return _get_next_prev(self, next, is_previous=False, period='month')
		return _get_next_prev(self, date, is_previous=False, period='month')

		def get_previous_month(self, date):
		"""
		Get the previous valid month.
		"""
		# prev must be the last day of the previous month.
		prev = date.replace(day=1) - datetime.timedelta(days=1)
		return _get_next_prev(self, prev, is_previous=True, period='month')
		return _get_next_prev(self, date, is_previous=True, period='month')

		def _get_next_month(self, date):
		"""
		Return the start date of the next interval.

		The interval is defined by start date <= item date < next start date.
		"""
		if date.month == 12:
		return date.replace(year=date.year + 1, month=1, day=1)
		else:
		return date.replace(month=date.month + 1, day=1)

		def _get_current_month(self, date):
		"""
		Return the start date of the previous interval.
		"""
		return date.replace(day=1)


		class DayMixin(object):
		@@ -92,7 +120,9 @@ class DayMixin(object):
		return self.day_format

		def get_day(self):
		"Return the day for which this view should display data"
		"""
		Return the day for which this view should display data.
		"""
		day = self.day
		if day is None:
		try:
		@@ -108,15 +138,27 @@ class DayMixin(object):
		"""
		Get the next valid day.
		"""
		next = date + datetime.timedelta(days=1)
		return _get_next_prev(self, next, is_previous=False, period='day')
		return _get_next_prev(self, date, is_previous=False, period='day')

		def get_previous_day(self, date):
		"""
		Get the previous valid day.
		"""
		prev = date - datetime.timedelta(days=1)
		return _get_next_prev(self, prev, is_previous=True, period='day')
		return _get_next_prev(self, date, is_previous=True, period='day')

		def _get_next_day(self, date):
		"""
		Return the start date of the next interval.

		The interval is defined by start date <= item date < next start date.
		"""
		return date + datetime.timedelta(days=1)

		def _get_current_day(self, date):
		"""
		Return the start date of the current interval.
		"""
		return date


		class WeekMixin(object):
		@@ -131,7 +173,9 @@ class WeekMixin(object):
		return self.week_format

		def get_week(self):
		"Return the week for which this view should display data"
		"""
		Return the week for which this view should display data
		"""
		week = self.week
		if week is None:
		try:
		@@ -147,19 +191,34 @@ class WeekMixin(object):
		"""
		Get the next valid week.
		"""
		# next must be the first day of the next week.
		next = date + datetime.timedelta(days=7 - self._get_weekday(date))
		return _get_next_prev(self, next, is_previous=False, period='week')
		return _get_next_prev(self, date, is_previous=False, period='week')

		def get_previous_week(self, date):
		"""
		Get the previous valid week.
		"""
		# prev must be the last day of the previous week.
		prev = date - datetime.timedelta(days=self._get_weekday(date) + 1)
		return _get_next_prev(self, prev, is_previous=True, period='week')
		return _get_next_prev(self, date, is_previous=True, period='week')

		def _get_next_week(self, date):
		"""
		Return the start date of the next interval.

		The interval is defined by start date <= item date < next start date.
		"""
		return date + datetime.timedelta(days=7 - self._get_weekday(date))

		def _get_current_week(self, date):
		"""
		Return the start date of the current interval.
		"""
		return date - datetime.timedelta(self._get_weekday(date))

		def _get_weekday(self, date):
		"""
		Return the weekday for a given date.

		The first day according to the week format is 0 and the last day is 6.
		"""
		week_format = self.get_week_format()
		if week_format == '%W': # week starts on Monday
		return date.weekday()
		@@ -168,6 +227,7 @@ class WeekMixin(object):
		else:
		raise ValueError("unknown week format: %s" % week_format)


		class DateMixin(object):
		"""
		Mixin class for views manipulating date-based data.
		@@ -267,7 +327,7 @@ class BaseDateListView(MultipleObjectMixin, DateMixin, View):
		paginate_by = self.get_paginate_by(qs)

		if not allow_future:
		now = timezone.now() if self.uses_datetime_field else datetime.date.today()
		now = timezone.now() if self.uses_datetime_field else timezone_today()
		qs = qs.filter(**{'%s__lte' % date_field: now})

		if not allow_empty:
		@@ -344,7 +404,7 @@ class BaseYearArchiveView(YearMixin, BaseDateListView):
		date = _date_from_string(year, self.get_year_format())

		since = self._make_date_lookup_arg(date)
		until = self._make_date_lookup_arg(datetime.date(date.year + 1, 1, 1))
		until = self._make_date_lookup_arg(self._get_next_year(date))
		lookup_kwargs = {
		'%s__gte' % date_field: since,
		'%s__lt' % date_field: until,
		@@ -392,12 +452,8 @@ class BaseMonthArchiveView(YearMixin, MonthMixin, BaseDateListView):
		date = _date_from_string(year, self.get_year_format(),
		month, self.get_month_format())

		# Construct a date-range lookup.
		since = self._make_date_lookup_arg(date)
		if date.month == 12:
		until = self._make_date_lookup_arg(datetime.date(date.year + 1, 1, 1))
		else:
		until = self._make_date_lookup_arg(datetime.date(date.year, date.month + 1, 1))
		until = self._make_date_lookup_arg(self._get_next_month(date))
		lookup_kwargs = {
		'%s__gte' % date_field: since,
		'%s__lt' % date_field: until,
		@@ -442,9 +498,8 @@ class BaseWeekArchiveView(YearMixin, WeekMixin, BaseDateListView):
		week_start, '%w',
		week, week_format)

		# Construct a date-range lookup.
		since = self._make_date_lookup_arg(date)
		until = self._make_date_lookup_arg(date + datetime.timedelta(days=7))
		until = self._make_date_lookup_arg(self._get_next_week(date))
		lookup_kwargs = {
		'%s__gte' % date_field: since,
		'%s__lt' % date_field: until,
		@@ -585,22 +640,22 @@ def _date_from_string(year, year_format, month='', month_format='', day='', day_
		})


		def _get_next_prev(generic_view, naive_result, is_previous, period):
		def _get_next_prev(generic_view, date, is_previous, period):
		"""
		Helper: Get the next or the previous valid date. The idea is to allow
		links on month/day views to never be 404s by never providing a date
		that'll be invalid for the given view.

		This is a bit complicated since it handles both next and previous months
		and days (for MonthArchiveView and DayArchiveView); hence the coupling to generic_view.
		This is a bit complicated since it handles different intervals of time,
		hence the coupling to generic_view.

		However in essence the logic comes down to:

		* If allow_empty and allow_future are both true, this is easy: just
		return the naive result (just the next/previous day or month,
		return the naive result (just the next/previous day/week/month,
		reguardless of object existence.)

		* If allow_empty is true, allow_future is false, and the naive month
		* If allow_empty is true, allow_future is false, and the naive result
		isn't in the future, then return it; otherwise return None.

		* If allow_empty is false and allow_future is true, return the next
		@@ -616,9 +671,23 @@ def _get_next_prev(generic_view, naive_result, is_previous, period):
		allow_empty = generic_view.get_allow_empty()
		allow_future = generic_view.get_allow_future()

		# If allow_empty is True the naive value will be valid
		get_current = getattr(generic_view, '_get_current_%s' % period)
		get_next = getattr(generic_view, '_get_next_%s' % period)

		# Bounds of the current interval
		start, end = get_current(date), get_next(date)

		# If allow_empty is True, the naive result will be valid
		if allow_empty:
		result = naive_result
		if is_previous:
		result = get_current(start - datetime.timedelta(days=1))
		else:
		result = end

		if allow_future or result <= timezone_today():
		return result
		else:
		return None

		# Otherwise, we'll need to go to the database to look for an object
		# whose date_field is at least (greater than/less than) the given
		@@ -627,12 +696,22 @@ def _get_next_prev(generic_view, naive_result, is_previous, period):
		# Construct a lookup and an ordering depending on whether we're doing
		# a previous date or a next date lookup.
		if is_previous:
		lookup = {'%s__lte' % date_field: generic_view._make_date_lookup_arg(naive_result)}
		lookup = {'%s__lt' % date_field: generic_view._make_date_lookup_arg(start)}
		ordering = '-%s' % date_field
		else:
		lookup = {'%s__gte' % date_field: generic_view._make_date_lookup_arg(naive_result)}
		lookup = {'%s__gte' % date_field: generic_view._make_date_lookup_arg(end)}
		ordering = date_field

		# Filter out objects in the future if appropriate.
		if not allow_future:
		# Fortunately, to match the implementation of allow_future,
		# we need __lte, which doesn't conflict with __lt above.
		if generic_view.uses_datetime_field:
		now = timezone.now()
		else:
		now = timezone_today()
		lookup['%s__lte' % date_field] = now

		qs = generic_view.get_queryset().filter(**lookup).order_by(ordering)

		# Snag the first object from the queryset; if it doesn't exist that
		@@ -640,26 +719,23 @@ def _get_next_prev(generic_view, naive_result, is_previous, period):
		try:
		result = getattr(qs[0], date_field)
		except IndexError:
		result = None
		return None

		# Convert datetimes to a dates
		if result and generic_view.uses_datetime_field:
		# Convert datetimes to dates in the current time zone.
		if generic_view.uses_datetime_field:
		if settings.USE_TZ:
		result = timezone.localtime(result)
		result = result.date()

		if result:
		if period == 'month':
		# first day of the month
		result = result.replace(day=1)
		elif period == 'week':
		# monday of the week
		result = result - datetime.timedelta(days=generic_view._get_weekday(result))
		elif period != 'day':
		raise ValueError('invalid period: %s' % period)

		# Check against future dates.
		if result and (allow_future or result < datetime.date.today()):
		return result
		# Return the first day of the period.
		return get_current(result)


		def timezone_today():
		"""
		Return the current date in the current time zone.
		"""
		if settings.USE_TZ:
		return timezone.localtime(timezone.now()).date()
		else:
		return None
		return datetime.date.today()