Added a template filter that is a replacement for Django's builtin 'date' filter, with a more polymorphic signature: It accepts either datetime or date input, and ignores time-specific format entries when handling a date.

- Legacy-Id: 17686

ietf/utils/templatetags/dateformat.py

@@ -0,0 +1,29 @@
+# Copyright The IETF Trust 2020, All Rights Reserved
+# -*- coding: utf-8 -*-
+
+import datetime
+
+from django.template import Library
+from django.template.defaultfilters import date
+
+import debug                            # pyflakes:ignore
+
+register = Library()
+
+elide_timefmt = str.maketrans("aAefgGhHiIOPsTuZ:", "                 ")
+
+@register.filter()
+def dateformat(value, arg=None):
+    """
+    Formats a date or datetime according to the given format.
+    Ignores the time-related format elements if a date is given.
+    """
+    if value in (None, ''):
+        return ''
+    debug.type('value')
+    if   isinstance(value, datetime.datetime):
+        pass
+    elif isinstance(value, datetime.date):
+        debug.say('got date')
+        arg = arg.translate(elide_timefmt).strip()
+    return date(value, arg)