Unicode-aware sorting of phone prefixes (#2523)

src/pretix/base/forms/questions.py

@@ -41,7 +41,6 @@ from io import BytesIO
 import dateutil.parser
 import pycountry
 import pytz
-from babel import Locale
 from django import forms
 from django.conf import settings
 from django.contrib import messages
@@ -52,7 +51,6 @@ from django.core.validators import (
 )
 from django.db.models import QuerySet
 from django.forms import Select, widgets
-from django.utils import translation
 from django.utils.formats import date_format
 from django.utils.html import escape
 from django.utils.safestring import mark_safe
@@ -87,7 +85,9 @@ from pretix.base.templatetags.rich_text import rich_text
 from pretix.control.forms import (
     ExtFileField, ExtValidationMixin, SizeValidationMixin, SplitDateTimeField,
 )
-from pretix.helpers.countries import CachedCountries
+from pretix.helpers.countries import (
+    CachedCountries, get_phone_prefixes_sorted_and_localized,
+)
 from pretix.helpers.escapejson import escapejson_attr
 from pretix.helpers.i18n import get_format_without_seconds
 from pretix.presale.signals import question_form_fields
@@ -264,17 +264,14 @@ class WrappedPhonePrefixSelect(Select):
 
     def __init__(self, initial=None):
         choices = [("", "---------")]
-        language = get_babel_locale()  # changed from default implementation that used the django locale
-        locale = Locale(translation.to_locale(language))
-        for prefix, values in _COUNTRY_CODE_TO_REGION_CODE.items():
-            prefix = "+%d" % prefix
-            if initial and initial in values:
-                self.initial = prefix
-            for country_code in values:
-                country_name = locale.territories.get(country_code)
-                if country_name:
-                    choices.append((prefix, "{} {}".format(country_name, prefix)))
-        super().__init__(choices=sorted(choices, key=lambda item: item[1]), attrs={'aria-label': pgettext_lazy('phonenumber', 'International area code')})
+
+        if initial:
+            for prefix, values in _COUNTRY_CODE_TO_REGION_CODE.items():
+                if initial in values:
+                    self.initial = "+%d" % prefix
+                    break
+        choices += get_phone_prefixes_sorted_and_localized()
+        super().__init__(choices=choices, attrs={'aria-label': pgettext_lazy('phonenumber', 'International area code')})
 
     def render(self, name, value, *args, **kwargs):
         return super().render(name, value or self.initial, *args, **kwargs)

src/pretix/helpers/countries.py

@@ -19,11 +19,17 @@
 # You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
 # <https://www.gnu.org/licenses/>.
 #
+import pyuca
+from babel.core import Locale
 from django.core.cache import cache
+from django.utils import translation
 from django_countries import Countries
 from django_countries.fields import CountryField
+from phonenumbers.data import _COUNTRY_CODE_TO_REGION_CODE
 
-from pretix.base.i18n import get_language_without_region
+from pretix.base.i18n import get_babel_locale, get_language_without_region
+
+_collator = pyuca.Collator()
 
 
 class CachedCountries(Countries):
@@ -83,3 +89,35 @@ class FastCountryField(CountryField):
             *self._check_multiple(),
             *self._check_max_length_attribute(**kwargs),
         ]
+
+
+_cached_phone_prefixes = {}
+
+
+def get_phone_prefixes_sorted_and_localized():
+    language = get_babel_locale()  # changed from default implementation that used the django locale
+
+    cache_key = "phoneprefixes:all:{}".format(language)
+    if cache_key in _cached_phone_prefixes:
+        return _cached_phone_prefixes[cache_key]
+
+    val = cache.get(cache_key)
+    if val:
+        _cached_phone_prefixes[cache_key] = val
+        return val
+
+    val = []
+
+    locale = Locale(translation.to_locale(language))
+    for prefix, values in _COUNTRY_CODE_TO_REGION_CODE.items():
+        prefix = "+%d" % prefix
+        for country_code in values:
+            country_name = locale.territories.get(country_code)
+            if country_name:
+                val.append((prefix, "{} {}".format(country_name, prefix)))
+
+    val = sorted(val, key=lambda item: _collator.sort_key(item[1]))
+
+    _cached_phone_prefixes[cache_key] = val
+    cache.set(cache_key, val, 3600 * 24 * 30)
+    return val