• Language: en

Source code for 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,
)


[docs]class YearMixin: """Mixin for views manipulating year-based data.""" year_format = '%Y' year = None
[docs] 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
[docs] 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
[docs] def get_next_year(self, date): """Get the next valid year.""" return _get_next_prev(self, date, is_previous=False, period='year')
[docs] 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)
[docs]class MonthMixin: """Mixin for views manipulating month-based data.""" month_format = '%b' month = None
[docs] 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
[docs] 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
[docs] def get_next_month(self, date): """Get the next valid month.""" return _get_next_prev(self, date, is_previous=False, period='month')
[docs] 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)
[docs]class DayMixin: """Mixin for views manipulating day-based data.""" day_format = '%d' day = None
[docs] 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
[docs] 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
[docs] def get_next_day(self, date): """Get the next valid day.""" return _get_next_prev(self, date, is_previous=False, period='day')
[docs] 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
[docs]class WeekMixin: """Mixin for views manipulating week-based data.""" week_format = '%U' week = None
[docs] 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
[docs] 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
[docs] 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)
[docs]class DateMixin: """Mixin class for views manipulating date-based data.""" date_field = None allow_future = False
[docs] 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
[docs] 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, timezone.get_current_timezone()) 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}
[docs]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)
[docs] 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
[docs] 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 = len(qs) == 0 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
[docs] def get_date_list_period(self): """ Get the aggregation period for the list of dates: 'year', 'month', or 'day'. """ return self.date_list_period
[docs] 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
[docs]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, {})
[docs]class ArchiveIndexView(MultipleObjectTemplateResponseMixin, BaseArchiveIndexView): """Top-level archive of date-based items.""" template_name_suffix = '_archive'
[docs]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
[docs]class YearArchiveView(MultipleObjectTemplateResponseMixin, BaseYearArchiveView): """List of objects published in a given year.""" template_name_suffix = '_archive_year'
[docs]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), })
[docs]class MonthArchiveView(MultipleObjectTemplateResponseMixin, BaseMonthArchiveView): """List of objects published in a given month.""" template_name_suffix = '_archive_month'
[docs]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), })
[docs]class WeekArchiveView(MultipleObjectTemplateResponseMixin, BaseWeekArchiveView): """List of objects published in a given week.""" template_name_suffix = '_archive_week'
[docs]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) })
[docs]class DayArchiveView(MultipleObjectTemplateResponseMixin, BaseDayArchiveView): """List of objects published on a given day.""" template_name_suffix = "_archive_day"
[docs]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())
[docs]class TodayArchiveView(MultipleObjectTemplateResponseMixin, BaseTodayArchiveView): """List of objects published today.""" template_name_suffix = "_archive_day"
[docs]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)
[docs]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()
Back to Top