feat(locale): add language switching and French translation

pyproject.toml

@@ -52,6 +52,10 @@ backup = "./src/manage.py export_backup"
 restore = "./src/manage.py import_backup"
 auto-backup = "./src/manage.py auto_backup"
 
+# Translations
+makemessages = "./src/manage.py makemessages -l fr --ignore=theme/* --ignore=staticfiles/* --ignore=venv/*"
+compilemessages = "./src/manage.py compilemessages"
+
 # Tests
 test = "pytest ./src --cov=src --cov-report=term-missing"
 test-fast = "pytest ./src -x -q"

src/accounts/urls.py

@@ -8,4 +8,5 @@
     path("profile/", views.profile_edit, name="profile_edit"),
     path("profile/validate-profile/", views.validate_profile_field, name="validate_profile_field"),
     path("profile/validate-password/", views.validate_password_field, name="validate_password_field"),
+    path("set-language/", views.set_language, name="set_language"),
 ]

src/accounts/views.py

@@ -1,8 +1,10 @@
+from django.conf import settings
 from django.contrib import messages
 from django.contrib.auth import update_session_auth_hash
 from django.contrib.auth.decorators import login_required
 from django.http import HttpResponse
 from django.shortcuts import redirect, render
+from django.utils import translation
 from django.utils.html import escape
 from django.utils.translation import gettext_lazy as _
 from django.views.decorators.http import require_POST
@@ -22,23 +24,28 @@ def profile_edit(request):
             profile_form = UserProfileForm(request.POST, instance=request.user)
             if profile_form.is_valid():
                 profile_form.save()
-                messages.success(request, _("Your profile has been updated."))
+                messages.success(request, _("Profile updated."))
                 return redirect("accounts:profile_edit")
         elif "change_password" in request.POST:
             password_form = CustomPasswordChangeForm(request.user, request.POST)
             if password_form.is_valid():
                 user = password_form.save()
                 # Keep the user logged in after password change
                 update_session_auth_hash(request, user)
-                messages.success(request, _("Your password has been changed."))
+                messages.success(request, _("Password changed."))
                 return redirect("accounts:profile_edit")
 
+    # Get current language and available languages
+    current_language = translation.get_language()
+
     return render(
         request,
         "accounts/profile_edit.html",
         {
             "profile_form": profile_form,
             "password_form": password_form,
+            "languages": settings.LANGUAGES,
+            "current_language": current_language,
         },
     )
 
@@ -70,3 +77,21 @@ def validate_password_field(request):
     form = CustomPasswordChangeForm(request.user, request.POST)
     field_name = request.POST.get("field_name")
     return _validate_field_htmx(form, field_name)
+
+
+@require_POST
+@login_required
+def set_language(request):
+    """Set the user's preferred language in session."""
+    language = request.POST.get("language")
+
+    # Validate the language code
+    if language and language in dict(settings.LANGUAGES):
+        translation.activate(language)
+        # Store language preference in session using Django's standard key
+        request.session["django_language"] = language
+        messages.success(request, _("Language preference updated."))
+    else:
+        messages.error(request, _("Invalid language selection."))
+
+    return redirect("accounts:profile_edit")

src/config/settings.py

@@ -75,6 +75,7 @@
     "django.middleware.security.SecurityMiddleware",
     "whitenoise.middleware.WhiteNoiseMiddleware",
     "django.contrib.sessions.middleware.SessionMiddleware",
+    "django.middleware.locale.LocaleMiddleware",  # Must be after SessionMiddleware
     "django.middleware.common.CommonMiddleware",
     "django.middleware.csrf.CsrfViewMiddleware",
     "django.contrib.auth.middleware.AuthenticationMiddleware",
@@ -150,6 +151,18 @@
 
 USE_TZ = True
 
+# Supported languages
+# https://docs.djangoproject.com/en/6.0/topics/i18n/translation/#how-django-discovers-language-preference
+LANGUAGES = [
+    ("en", "English"),
+    ("fr", "Français"),
+]
+
+# Path where Django will look for translation files
+LOCALE_PATHS = [
+    BASE_DIR / "locale",
+]
+
 # Static files (CSS, JavaScript, Images)
 # https://docs.djangoproject.com/en/6.0/howto/static-files/
 

src/core/models.py

@@ -5,7 +5,7 @@
 from django.core.validators import MaxValueValidator, MinValueValidator
 from django.db import models
 from django.utils import timezone
-from django.utils.translation import gettext as _
+from django.utils.translation import gettext_lazy as _
 from markdownfield.models import MarkdownField, RenderedMarkdownField
 from markdownfield.validators import VALIDATOR_STANDARD
 from partial_date import PartialDateField