From 47cbec5a56323e8f2decf1ddbab477d95691c069 Mon Sep 17 00:00:00 2001
From: Jonathan Weth <git@jonathanweth.de>
Date: Thu, 25 Mar 2021 20:59:22 +0100
Subject: [PATCH] Make next_lesson work with multiple validity ranges and year
changes
---
aleksis/apps/chronos/managers.py | 90 ++++++++++++++++++++++++++++----
1 file changed, 81 insertions(+), 9 deletions(-)
diff --git a/aleksis/apps/chronos/managers.py b/aleksis/apps/chronos/managers.py
index 5c104ba5..ca92c3eb 100644
--- a/aleksis/apps/chronos/managers.py
+++ b/aleksis/apps/chronos/managers.py
@@ -1,6 +1,6 @@
from datetime import date, datetime, timedelta
from enum import Enum
-from typing import Iterable, List, Optional, Union
+from typing import Dict, Iterable, List, Optional, Union
from django.contrib.sites.managers import CurrentSiteManager as _CurrentSiteManager
from django.db import models
@@ -10,7 +10,7 @@ from django.db.models.functions import Concat
from calendarweek import CalendarWeek
-from aleksis.apps.chronos.util.date import week_weekday_from_date
+from aleksis.apps.chronos.util.date import week_weekday_from_date, week_weekday_to_date
from aleksis.core.managers import DateRangeQuerySetMixin, SchoolTermRelatedQuerySet
from aleksis.core.models import Group, Person
from aleksis.core.util.core_helpers import get_site_preferences
@@ -375,28 +375,100 @@ class LessonDataQuerySet(models.QuerySet, WeekQuerySetMixin):
return lesson_periods
- def next_lesson(self, reference: "LessonPeriod", offset: Optional[int] = 1) -> "LessonPeriod":
+ def group_by_validity(self) -> Dict["ValidityRange", List["LessonPeriod"]]:
+ """Group lesson periods by validity range as dictionary."""
+ lesson_periods_by_validity = {}
+ for lesson_period in self:
+ lesson_periods_by_validity.setdefault(lesson_period.lesson.validity, [])
+ lesson_periods_by_validity[lesson_period.lesson.validity].append(lesson_period)
+ return lesson_periods_by_validity
+
+ def next_lesson(
+ self, reference: "LessonPeriod", offset: Optional[int] = 1
+ ) -> Optional["LessonPeriod"]:
"""Get another lesson in an ordered set of lessons.
By default, it returns the next lesson in the set. By passing the offset argument,
the n-th next lesson can be selected. By passing a negative number, the n-th
previous lesson can be selected.
+
+ This function will handle week, year and validity range changes automatically
+ if the queryset contains enough lesson data.
"""
- index = list(self.values_list("id", flat=True)).index(reference.id)
+ # Group lesson periods by validity to handle validity range changes correctly
+ lesson_periods_by_validity = self.group_by_validity()
+ validity_ranges = list(lesson_periods_by_validity.keys())
+
+ # List with lesson periods in the validity range of the reference lesson period
+ current_lesson_periods = lesson_periods_by_validity[reference.lesson.validity]
+ pks = [lesson_period.pk for lesson_period in current_lesson_periods]
+
+ # Position of the reference lesson period
+ index = pks.index(reference.id)
next_index = index + offset
- if next_index > self.count() - 1:
- next_index %= self.count()
+ if next_index > len(pks) - 1:
+ next_index %= len(pks)
week = reference._week + 1
elif next_index < 0:
- next_index = self.count() + next_index
+ next_index = len(pks) + next_index
week = reference._week - 1
else:
week = reference._week
- week = CalendarWeek(week=week, year=reference.lesson.get_year(week))
+ # Check if selected week makes a year change necessary
+ year = reference._year
+ if week < 1:
+ year -= 1
+ week = CalendarWeek.get_last_week_of_year(year)
+ elif week > CalendarWeek.get_last_week_of_year(year):
+ year += 1
+ week = 1
+
+ # Get the next lesson period in this validity range and it's date
+ # to check whether the validity range has to be changed
+ week = CalendarWeek(week=week, year=year)
+ next_lesson_period = current_lesson_periods[next_index]
+ next_lesson_period_date = week_weekday_to_date(week, next_lesson_period.period.period)
+
+ validity_index = validity_ranges.index(next_lesson_period.lesson.validity)
+
+ # If date of next lesson period is out of validity range (smaller) ...
+ if next_lesson_period_date < next_lesson_period.lesson.validity.date_start:
+ # ... we have to get the lesson period from the previous validity range
+ if validity_index == 0:
+ # There are no validity ranges (and thus no lessons)
+ # in the school term before this lesson period
+ return None
+
+ # Get new validity range and last lesson period of this validity range
+ new_validity = validity_ranges[validity_index - 1]
+ next_lesson_period = lesson_periods_by_validity[new_validity][-1]
+
+ # Build new week with the date from the new validity range/lesson period
+ week = CalendarWeek(
+ week=new_validity.date_end.isocalendar()[1], year=new_validity.date_end.year
+ )
+
+ # If date of next lesson period is out of validity range (larger) ...
+ elif next_lesson_period_date > next_lesson_period.lesson.validity.date_end:
+ # ... we have to get the lesson period from the next validity range
+ if validity_index >= len(validity_ranges):
+ # There are no validity ranges (and thus no lessons)
+ # in the school term after this lesson period
+ return None
+
+ # Get new validity range and first lesson period of this validity range
+ new_validity = validity_ranges[validity_index + 1]
+ next_lesson_period = lesson_periods_by_validity[new_validity][0]
+
+ # Build new week with the date from the new validity range/lesson period
+ week = CalendarWeek(
+ week=new_validity.date_start.isocalendar()[1], year=new_validity.date_start.year
+ )
- return self.annotate_week(week).all()[next_index]
+ # Do a new query here to be able to annotate the new week
+ return self.annotate_week(week).get(pk=next_lesson_period.pk)
class LessonPeriodQuerySet(LessonDataQuerySet, GroupByPeriodsMixin):
--
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