Feature:support alter relativedelta field on admin

README.rst

@@ -27,6 +27,16 @@ perform arithmetic on them within the database.
 Usage
 -----
 
+Setup:
+
+.. code:: python
+
+    INSTALLED_APPS = [
+        '...',
+        'relativedeltafield',
+        '...'
+    ]
+
 Using the field is straightforward.  You can add the field to your
 model like so:
 
@@ -79,6 +89,14 @@ sure that after a ``save()``, your fields are both normalized
 and validated.
 
 
+You can also use on admin:
+
+.. code:: python
+    from django.contrib import admin
+
+    admin.site.register(MyModel)
+
+
 Limitations and pitfalls
 ------------------------
 

relativedeltafield/__init__.py

@@ -1,10 +1,13 @@
 import re
 
 from django.core.exceptions import ValidationError
+from django.contrib.admin.options import FORMFIELD_FOR_DBFIELD_DEFAULTS
 from django.db import models
+from django.forms.widgets import MultiWidget, TimeInput, NumberInput
 from django.utils.translation import ugettext_lazy as _
+from django import forms
 
-from datetime import timedelta
+from datetime import timedelta, time
 from dateutil.relativedelta import relativedelta
 
 # This is not quite ISO8601, as it allows the SQL/Postgres extension
@@ -75,6 +78,61 @@ def format_relativedelta(relativedelta):
 
 
 
+class RelativeDetailInput(MultiWidget):
+	template_name = 'admin/widgets/relativedelta.html'
+
+	def __init__(self, attrs=None):
+		widgets = (
+			NumberInput(attrs=attrs),
+			NumberInput(attrs=attrs),
+			NumberInput(attrs=attrs),
+			TimeInput(attrs=attrs),
+		)
+		super().__init__(widgets)
+
+	def get_context(self, name, value, attrs):
+		context = super().get_context(name, value, attrs)
+		context.update({
+			'year_label': _('Year'),
+			'month_label': _('Month'),
+			'day_label': _('Day'),
+			'time_label': _('Time'),
+		})
+		return context
+
+	def decompress(self, value):
+		if value:
+			return [value.years, value.months, value.days,
+					time(hour=value.hours, minute=value.minutes,
+					second=value.seconds,
+					microsecond=value.microseconds)]
+		return [0, 0, 0, time()]
+
+
+class RelativeDetailFormField(forms.MultiValueField):
+	def __init__(self, **kwargs):
+		fields = [
+			forms.IntegerField(),
+			forms.IntegerField(),
+			forms.IntegerField(),
+			forms.TimeField(),
+		]
+		super().__init__(
+			fields=fields,
+			require_all_fields=False, **kwargs
+		)
+
+	def compress(self, data_list):
+		kwargs = {
+			'years': data_list[0],
+			'months': data_list[1],
+			'days': data_list[2],
+			'hours': data_list[3].hour,
+			'minutes': data_list[3].minute,
+		}
+		return relativedelta(**kwargs).normalized()
+
+
 class RelativeDeltaField(models.Field):
 	"""Stores dateutil.relativedelta.relativedelta objects.
 
@@ -150,3 +208,10 @@ def convert_relativedeltafield_value(self, value, expression, connection, contex
 	def value_to_string(self, obj):
 		val = self.value_from_object(obj)
 		return '' if val is None else format_relativedelta(val)
+
+
+FORMFIELD_FOR_DBFIELD_DEFAULTS[RelativeDeltaField] = {
+	'form_class': RelativeDetailFormField,
+	'widget': RelativeDetailInput
+}
+

relativedeltafield/templates/admin/widgets/relativedelta.html

@@ -0,0 +1,6 @@
+<p>
+    {{ year_label }}: {% with widget=widget.subwidgets.0 %}{% include widget.template_name %}{% endwith %}
+    {{ month_label }}: {% with widget=widget.subwidgets.1 %}{% include widget.template_name %}{% endwith %}
+    {{ day_label }}: {% with widget=widget.subwidgets.2 %}{% include widget.template_name %}{% endwith %}<br>
+    {{ time_label }}: {% with widget=widget.subwidgets.3 %}{% include widget.template_name %}{% endwith %}
+</p>