Add per-user timezone setting

The `0002` migration is to make it so it doesn't show as needing a
migration if Django's list of timezones ever changes.

https://dev.to/nessita/django-migrations-by-choice-32n7

Author: trey

.pre-commit-config.yaml

@@ -14,6 +14,7 @@ repos:
     rev: 23.3.0
     hooks:
       - id: black
+        exclude: ^core/migrations/
   - repo: https://github.com/pycqa/flake8
     rev: 6.0.0
     hooks:

config/settings.py-tpl

@@ -14,6 +14,7 @@ from django.core.management.utils import get_random_secret_key
 from pathlib import Path
 from environs import Env
 from warnings import filterwarnings
+from pytz import common_timezones
 
 env = Env()
 # Read .env into os.environ
@@ -72,6 +73,7 @@ MIDDLEWARE = [
     "django.contrib.auth.middleware.AuthenticationMiddleware",
     "django.contrib.messages.middleware.MessageMiddleware",
     "django.middleware.clickjacking.XFrameOptionsMiddleware",
+    "core.middleware.TimezoneMiddleware",
     "debug_toolbar.middleware.DebugToolbarMiddleware",
     "django_htmx.middleware.HtmxMiddleware",
     "django_browser_reload.middleware.BrowserReloadMiddleware",
@@ -134,6 +136,8 @@ LANGUAGE_CODE = "en-us"
 
 TIME_ZONE = "UTC"
 
+TIME_ZONES = [(tz, tz) for tz in common_timezones]
+
 USE_I18N = True
 
 USE_TZ = True

core/admin.py

@@ -11,7 +11,7 @@ class UserAdmin(DjangoUserAdmin):
 
     fieldsets = (
         (None, {"fields": ("email", "password")}),
-        (_("Personal info"), {"fields": ("first_name", "last_name")}),
+        (_("Personal info"), {"fields": ("first_name", "last_name", "timezone")}),
         (
             _("Permissions"),
             {

core/middleware.py

@@ -0,0 +1,24 @@
+import pytz
+from django.utils import timezone
+from django.conf import settings
+
+
+class TimezoneMiddleware:
+    """
+    Automatically set the timezone to what the user has chosen.
+    """
+
+    def __init__(self, get_response):
+        self.get_response = get_response
+
+    def __call__(self, request):
+        if request.user.is_authenticated:
+            tzname = request.user.timezone
+            if tzname:
+                timezone.activate(pytz.timezone(tzname))
+            else:
+                timezone.activate(pytz.timezone(settings.TIME_ZONE))
+        else:
+            timezone.deactivate()
+
+        return self.get_response(request)

core/models.py

@@ -1,6 +1,7 @@
 from django.contrib.auth.models import AbstractUser, BaseUserManager
 from django.db import models
 from django.utils.translation import gettext_lazy as _
+from django.conf import settings
 
 
 class UserManager(BaseUserManager):
@@ -42,6 +43,12 @@ class User(AbstractUser):
 
     username = None
     email = models.EmailField(_("email address"), unique=True)
+    timezone = models.CharField(
+        max_length=40,
+        blank=True,
+        choices=settings.TIME_ZONES,
+        default=settings.TIME_ZONE,
+    )
     # Add more fields here.
 
     objects = UserManager()

dev/0002_adjust_timezone_migration.py

@@ -0,0 +1,21 @@
+from django.db import migrations, models
+from django.conf import settings
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("core", "0001_initial"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="user",
+            name="timezone",
+            field=models.CharField(
+                blank=True,
+                choices=settings.TIME_ZONES,
+                default=settings.TIME_ZONE,
+                max_length=40,
+            ),
+        ),
+    ]

dev/setup.sh

@@ -168,6 +168,7 @@ gum style --border normal --margin "1" --padding "0 2" --border-foreground 212 \
   "Warming up $(gum style --foreground 212 'database') and $(gum style --foreground 212 'static files')…"
 gum spin --title "Collecting static files" -- python manage.py collectstatic
 gum spin --title "Warming up the database" -- python manage.py makemigrations
+gum spin --title "Warming up the database" -- mv dev/0002_adjust_timezone_migration.py core/migrations/0002_adjust_timezone_migration.py
 gum spin --title "Warming up the database" -- python manage.py migrate
 gum spin --title "Creating initial superuser account" -- python manage.py createsuperuser --noinput --email=$EMAIL
 

dev/test-build

@@ -15,6 +15,7 @@ case $yn in
         .venv/bin/pip-compile --resolver=backtracking requirements/requirements.in
         .venv/bin/python -m pip install -r requirements/requirements.txt
         .venv/bin/python manage.py makemigrations
+        mv dev/0002_adjust_timezone_migration.py core/migrations/0002_adjust_timezone_migration.py
         .venv/bin/python manage.py migrate --noinput
         .venv/bin/python manage.py collectstatic --noinput
         source $HOME/.nvm/nvm.sh

requirements/requirements.in

@@ -17,4 +17,5 @@ pip-lock
 pip-tools
 pre-commit
 pytest-django
+pytz
 whitenoise

requirements/requirements.txt

@@ -157,6 +157,8 @@ pytest-django==4.8.0
     # via -r requirements/requirements.in
 python-dotenv==1.0.1
     # via environs
+pytz==2024.1
+    # via -r requirements/requirements.in
 pyyaml==6.0.1
     # via
     #   djlint