Πηγαίος κώδικας για το django.views.generic.dates
import datetime
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.db import models
from django.http import Http404
from django.utils import timezone
from django.utils.functional import cached_property
from django.utils.translation import gettext as _
from django.views.generic.base import View
from django.views.generic.detail import (
BaseDetailView, SingleObjectTemplateResponseMixin,
)
from django.views.generic.list import (
MultipleObjectMixin, MultipleObjectTemplateResponseMixin,
)
[τεκμηρίωση]class YearMixin:
"""Mixin for views manipulating year-based data."""
year_format = '%Y'
year = None
[τεκμηρίωση] def get_year_format(self):
"""
Get a year format string in strptime syntax to be used to parse the
year from url variables.
"""
return self.year_format
[τεκμηρίωση] def get_year(self):
"""Return the year for which this view should display data."""
year = self.year
if year is None:
try:
year = self.kwargs['year']
except KeyError:
try:
year = self.request.GET['year']
except KeyError:
raise Http404(_("No year specified"))
return year
[τεκμηρίωση] def get_next_year(self, date):
"""Get the next valid year."""
return _get_next_prev(self, date, is_previous=False, period='year')
[τεκμηρίωση] def get_previous_year(self, date):
"""Get the previous valid year."""
return _get_next_prev(self, date, is_previous=True, period='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.
"""
try:
return date.replace(year=date.year + 1, month=1, day=1)
except ValueError:
raise Http404(_("Date out of range"))
def _get_current_year(self, date):
"""Return the start date of the current interval."""
return date.replace(month=1, day=1)
[τεκμηρίωση]class MonthMixin:
"""Mixin for views manipulating month-based data."""
month_format = '%b'
month = None
[τεκμηρίωση] def get_month_format(self):
"""
Get a month format string in strptime syntax to be used to parse the
month from url variables.
"""
return self.month_format
[τεκμηρίωση] def get_month(self):
"""Return the month for which this view should display data."""
month = self.month
if month is None:
try:
month = self.kwargs['month']
except KeyError:
try:
month = self.request.GET['month']
except KeyError:
raise Http404(_("No month specified"))
return month
[τεκμηρίωση] def get_next_month(self, date):
"""Get the next valid month."""
return _get_next_prev(self, date, is_previous=False, period='month')
[τεκμηρίωση] def get_previous_month(self, date):
"""Get the previous valid 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:
try:
return date.replace(year=date.year + 1, month=1, day=1)
except ValueError:
raise Http404(_("Date out of range"))
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)
[τεκμηρίωση]class DayMixin:
"""Mixin for views manipulating day-based data."""
day_format = '%d'
day = None
[τεκμηρίωση] def get_day_format(self):
"""
Get a day format string in strptime syntax to be used to parse the day
from url variables.
"""
return self.day_format
[τεκμηρίωση] def get_day(self):
"""Return the day for which this view should display data."""
day = self.day
if day is None:
try:
day = self.kwargs['day']
except KeyError:
try:
day = self.request.GET['day']
except KeyError:
raise Http404(_("No day specified"))
return day
[τεκμηρίωση] def get_next_day(self, date):
"""Get the next valid day."""
return _get_next_prev(self, date, is_previous=False, period='day')
[τεκμηρίωση] def get_previous_day(self, date):
"""Get the previous valid 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
[τεκμηρίωση]class WeekMixin:
"""Mixin for views manipulating week-based data."""
week_format = '%U'
week = None
[τεκμηρίωση] def get_week_format(self):
"""
Get a week format string in strptime syntax to be used to parse the
week from url variables.
"""
return self.week_format
[τεκμηρίωση] def get_week(self):
"""Return the week for which this view should display data."""
week = self.week
if week is None:
try:
week = self.kwargs['week']
except KeyError:
try:
week = self.request.GET['week']
except KeyError:
raise Http404(_("No week specified"))
return week
[τεκμηρίωση] def get_next_week(self, date):
"""Get the next valid week."""
return _get_next_prev(self, date, is_previous=False, period='week')
def get_previous_week(self, date):
"""Get the previous valid 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.
"""
try:
return date + datetime.timedelta(days=7 - self._get_weekday(date))
except OverflowError:
raise Http404(_("Date out of range"))
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()
elif week_format == '%U': # week starts on Sunday
return (date.weekday() + 1) % 7
else:
raise ValueError("unknown week format: %s" % week_format)
[τεκμηρίωση]class DateMixin:
"""Mixin class for views manipulating date-based data."""
date_field = None
allow_future = False
[τεκμηρίωση] def get_date_field(self):
"""Get the name of the date field to be used to filter by."""
if self.date_field is None:
raise ImproperlyConfigured("%s.date_field is required." % self.__class__.__name__)
return self.date_field
[τεκμηρίωση] def get_allow_future(self):
"""
Return `True` if the view should be allowed to display objects from
the future.
"""
return self.allow_future
# Note: the following three methods only work in subclasses that also
# inherit SingleObjectMixin or MultipleObjectMixin.
@cached_property
def uses_datetime_field(self):
"""
Return `True` if the date field is a `DateTimeField` and `False`
if it's a `DateField`.
"""
model = self.get_queryset().model if self.model is None else self.model
field = model._meta.get_field(self.get_date_field())
return isinstance(field, models.DateTimeField)
def _make_date_lookup_arg(self, value):
"""
Convert a date into a datetime when the date field is a DateTimeField.
When time zone support is enabled, `date` is assumed to be in the
current time zone, so that displayed items are consistent with the URL.
"""
if self.uses_datetime_field:
value = datetime.datetime.combine(value, datetime.time.min)
if settings.USE_TZ:
value = timezone.make_aware(value)
return value
def _make_single_date_lookup(self, date):
"""
Get the lookup kwargs for filtering on a single date.
If the date field is a DateTimeField, we can't just filter on
date_field=date because that doesn't take the time into account.
"""
date_field = self.get_date_field()
if self.uses_datetime_field:
since = self._make_date_lookup_arg(date)
until = self._make_date_lookup_arg(date + datetime.timedelta(days=1))
return {
'%s__gte' % date_field: since,
'%s__lt' % date_field: until,
}
else:
# Skip self._make_date_lookup_arg, it's a no-op in this branch.
return {date_field: date}
[τεκμηρίωση]class BaseDateListView(MultipleObjectMixin, DateMixin, View):
"""Abstract base class for date-based views displaying a list of objects."""
allow_empty = False
date_list_period = 'year'
def get(self, request, *args, **kwargs):
self.date_list, self.object_list, extra_context = self.get_dated_items()
context = self.get_context_data(
object_list=self.object_list,
date_list=self.date_list,
**extra_context
)
return self.render_to_response(context)
[τεκμηρίωση] def get_dated_items(self):
"""Obtain the list of dates and items."""
raise NotImplementedError('A DateView must provide an implementation of get_dated_items()')
def get_ordering(self):
"""
Return the field or fields to use for ordering the queryset; use the
date field by default.
"""
return '-%s' % self.get_date_field() if self.ordering is None else self.ordering
[τεκμηρίωση] def get_dated_queryset(self, **lookup):
"""
Get a queryset properly filtered according to `allow_future` and any
extra lookup kwargs.
"""
qs = self.get_queryset().filter(**lookup)
date_field = self.get_date_field()
allow_future = self.get_allow_future()
allow_empty = self.get_allow_empty()
paginate_by = self.get_paginate_by(qs)
if not allow_future:
now = timezone.now() if self.uses_datetime_field else timezone_today()
qs = qs.filter(**{'%s__lte' % date_field: now})
if not allow_empty:
# When pagination is enabled, it's better to do a cheap query
# than to load the unpaginated queryset in memory.
is_empty = not qs if paginate_by is None else not qs.exists()
if is_empty:
raise Http404(_("No %(verbose_name_plural)s available") % {
'verbose_name_plural': qs.model._meta.verbose_name_plural,
})
return qs
[τεκμηρίωση] def get_date_list_period(self):
"""
Get the aggregation period for the list of dates: 'year', 'month', or
'day'.
"""
return self.date_list_period
[τεκμηρίωση] def get_date_list(self, queryset, date_type=None, ordering='ASC'):
"""
Get a date list by calling `queryset.dates/datetimes()`, checking
along the way for empty lists that aren't allowed.
"""
date_field = self.get_date_field()
allow_empty = self.get_allow_empty()
if date_type is None:
date_type = self.get_date_list_period()
if self.uses_datetime_field:
date_list = queryset.datetimes(date_field, date_type, ordering)
else:
date_list = queryset.dates(date_field, date_type, ordering)
if date_list is not None and not date_list and not allow_empty:
raise Http404(
_("No %(verbose_name_plural)s available") % {
'verbose_name_plural': queryset.model._meta.verbose_name_plural,
}
)
return date_list
[τεκμηρίωση]class BaseArchiveIndexView(BaseDateListView):
"""
Base class for archives of date-based items. Requires a response mixin.
"""
context_object_name = 'latest'
def get_dated_items(self):
"""Return (date_list, items, extra_context) for this request."""
qs = self.get_dated_queryset()
date_list = self.get_date_list(qs, ordering='DESC')
if not date_list:
qs = qs.none()
return (date_list, qs, {})
[τεκμηρίωση]class ArchiveIndexView(MultipleObjectTemplateResponseMixin, BaseArchiveIndexView):
"""Top-level archive of date-based items."""
template_name_suffix = '_archive'
[τεκμηρίωση]class BaseYearArchiveView(YearMixin, BaseDateListView):
"""List of objects published in a given year."""
date_list_period = 'month'
make_object_list = False
def get_dated_items(self):
"""Return (date_list, items, extra_context) for this request."""
year = self.get_year()
date_field = self.get_date_field()
date = _date_from_string(year, self.get_year_format())
since = self._make_date_lookup_arg(date)
until = self._make_date_lookup_arg(self._get_next_year(date))
lookup_kwargs = {
'%s__gte' % date_field: since,
'%s__lt' % date_field: until,
}
qs = self.get_dated_queryset(**lookup_kwargs)
date_list = self.get_date_list(qs)
if not self.get_make_object_list():
# We need this to be a queryset since parent classes introspect it
# to find information about the model.
qs = qs.none()
return (date_list, qs, {
'year': date,
'next_year': self.get_next_year(date),
'previous_year': self.get_previous_year(date),
})
def get_make_object_list(self):
"""
Return `True` if this view should contain the full list of objects in
the given year.
"""
return self.make_object_list
[τεκμηρίωση]class YearArchiveView(MultipleObjectTemplateResponseMixin, BaseYearArchiveView):
"""List of objects published in a given year."""
template_name_suffix = '_archive_year'
[τεκμηρίωση]class BaseMonthArchiveView(YearMixin, MonthMixin, BaseDateListView):
"""List of objects published in a given month."""
date_list_period = 'day'
def get_dated_items(self):
"""Return (date_list, items, extra_context) for this request."""
year = self.get_year()
month = self.get_month()
date_field = self.get_date_field()
date = _date_from_string(year, self.get_year_format(),
month, self.get_month_format())
since = self._make_date_lookup_arg(date)
until = self._make_date_lookup_arg(self._get_next_month(date))
lookup_kwargs = {
'%s__gte' % date_field: since,
'%s__lt' % date_field: until,
}
qs = self.get_dated_queryset(**lookup_kwargs)
date_list = self.get_date_list(qs)
return (date_list, qs, {
'month': date,
'next_month': self.get_next_month(date),
'previous_month': self.get_previous_month(date),
})
[τεκμηρίωση]class MonthArchiveView(MultipleObjectTemplateResponseMixin, BaseMonthArchiveView):
"""List of objects published in a given month."""
template_name_suffix = '_archive_month'
[τεκμηρίωση]class BaseWeekArchiveView(YearMixin, WeekMixin, BaseDateListView):
"""List of objects published in a given week."""
def get_dated_items(self):
"""Return (date_list, items, extra_context) for this request."""
year = self.get_year()
week = self.get_week()
date_field = self.get_date_field()
week_format = self.get_week_format()
week_start = {
'%W': '1',
'%U': '0',
}[week_format]
date = _date_from_string(year, self.get_year_format(),
week_start, '%w',
week, week_format)
since = self._make_date_lookup_arg(date)
until = self._make_date_lookup_arg(self._get_next_week(date))
lookup_kwargs = {
'%s__gte' % date_field: since,
'%s__lt' % date_field: until,
}
qs = self.get_dated_queryset(**lookup_kwargs)
return (None, qs, {
'week': date,
'next_week': self.get_next_week(date),
'previous_week': self.get_previous_week(date),
})
[τεκμηρίωση]class WeekArchiveView(MultipleObjectTemplateResponseMixin, BaseWeekArchiveView):
"""List of objects published in a given week."""
template_name_suffix = '_archive_week'
[τεκμηρίωση]class BaseDayArchiveView(YearMixin, MonthMixin, DayMixin, BaseDateListView):
"""List of objects published on a given day."""
def get_dated_items(self):
"""Return (date_list, items, extra_context) for this request."""
year = self.get_year()
month = self.get_month()
day = self.get_day()
date = _date_from_string(year, self.get_year_format(),
month, self.get_month_format(),
day, self.get_day_format())
return self._get_dated_items(date)
def _get_dated_items(self, date):
"""
Do the actual heavy lifting of getting the dated items; this accepts a
date object so that TodayArchiveView can be trivial.
"""
lookup_kwargs = self._make_single_date_lookup(date)
qs = self.get_dated_queryset(**lookup_kwargs)
return (None, qs, {
'day': date,
'previous_day': self.get_previous_day(date),
'next_day': self.get_next_day(date),
'previous_month': self.get_previous_month(date),
'next_month': self.get_next_month(date)
})
[τεκμηρίωση]class DayArchiveView(MultipleObjectTemplateResponseMixin, BaseDayArchiveView):
"""List of objects published on a given day."""
template_name_suffix = "_archive_day"
[τεκμηρίωση]class BaseTodayArchiveView(BaseDayArchiveView):
"""List of objects published today."""
def get_dated_items(self):
"""Return (date_list, items, extra_context) for this request."""
return self._get_dated_items(datetime.date.today())
[τεκμηρίωση]class TodayArchiveView(MultipleObjectTemplateResponseMixin, BaseTodayArchiveView):
"""List of objects published today."""
template_name_suffix = "_archive_day"
[τεκμηρίωση]class BaseDateDetailView(YearMixin, MonthMixin, DayMixin, DateMixin, BaseDetailView):
"""
Detail view of a single object on a single date; this differs from the
standard DetailView by accepting a year/month/day in the URL.
"""
def get_object(self, queryset=None):
"""Get the object this request displays."""
year = self.get_year()
month = self.get_month()
day = self.get_day()
date = _date_from_string(year, self.get_year_format(),
month, self.get_month_format(),
day, self.get_day_format())
# Use a custom queryset if provided
qs = self.get_queryset() if queryset is None else queryset
if not self.get_allow_future() and date > datetime.date.today():
raise Http404(_(
"Future %(verbose_name_plural)s not available because "
"%(class_name)s.allow_future is False."
) % {
'verbose_name_plural': qs.model._meta.verbose_name_plural,
'class_name': self.__class__.__name__,
})
# Filter down a queryset from self.queryset using the date from the
# URL. This'll get passed as the queryset to DetailView.get_object,
# which'll handle the 404
lookup_kwargs = self._make_single_date_lookup(date)
qs = qs.filter(**lookup_kwargs)
return super().get_object(queryset=qs)
[τεκμηρίωση]class DateDetailView(SingleObjectTemplateResponseMixin, BaseDateDetailView):
"""
Detail view of a single object on a single date; this differs from the
standard DetailView by accepting a year/month/day in the URL.
"""
template_name_suffix = '_detail'
def _date_from_string(year, year_format, month='', month_format='', day='', day_format='', delim='__'):
"""
Get a datetime.date object given a format string and a year, month, and day
(only year is mandatory). Raise a 404 for an invalid date.
"""
format = year_format + delim + month_format + delim + day_format
datestr = str(year) + delim + str(month) + delim + str(day)
try:
return datetime.datetime.strptime(datestr, format).date()
except ValueError:
raise Http404(_("Invalid date string '%(datestr)s' given format '%(format)s'") % {
'datestr': datestr,
'format': format,
})
def _get_next_prev(generic_view, date, is_previous, period):
"""
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 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/week/month,
regardless of object existence.)
* 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
date *that contains a valid object*, even if it's in the future. If
there are no next objects, return None.
* If allow_empty is false and allow_future is false, return the next
date that contains a valid object. If that date is in the future, or
if there are no next objects, return None.
"""
date_field = generic_view.get_date_field()
allow_empty = generic_view.get_allow_empty()
allow_future = generic_view.get_allow_future()
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:
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
# naive result
else:
# 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__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(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
# means there's no next/previous link available.
try:
result = getattr(qs[0], date_field)
except IndexError:
return None
# 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()
# 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.localdate()
else:
return datetime.date.today()
