SplitDateTimeWidget bug

[riparian-imakedonsky]

Widget tweaks cuts off initial classes provided to subwidgets.

Used both directly(not through custom widget, and with custom widget). Result is same.

Consider following usage:

Template:
{% render_field field class+='validate' %}

Form:

class MySparEditForm(forms.ModelForm):
    posting_start = forms.SplitDateTimeField(widget=SplitDateTimeWidget(time_attrs={'class': 'datepicker'}, date_attrs={'class': 'timepicker'}))

    class Meta:
        model = Spar
        widgets = {
            'posting_end':  DateTimePicker(),
            'main_text': TextArea(),
            'image': forms.FileInput(),
            'active': CheckBox()
        }
        fields = [
            'active',
            'name',
            'type',
            'description',
            'main_text',
            'image',
            'participants',
            'posting_start',
            'posting_end',
        ]

And DateTimePicker widget code:

def add_classes(attrs, classes):
    if 'class' in attrs:
        attrs['class'] += f' {classes}'
    else:
        attrs['class'] = classes


class DateTimePicker(SplitDateTimeWidget):
    datepicker_classes = 'datepicker'
    timepicker_classes = 'timepicker'

    def __init__(self, attrs=None, date_format=None, time_format=None, date_attrs=None, time_attrs=None):
        date_attrs, time_attrs = date_attrs or {}, time_attrs or {}
        add_classes(date_attrs, self.datepicker_classes)
        add_classes(time_attrs, self.timepicker_classes)
        super().__init__(attrs, date_format, time_format, date_attrs, time_attrs)

Then result is:
http://joxi.ru/MAjBv7I40kDdAe.png

It replaces initial classes on subwidgets with provided via += instead of concatenating them.

[zodman]

i can reproduce with this:

diff --git a/widget_tweaks/tests.py b/widget_tweaks/tests.py
index ee210a2..a944afe 100644
--- a/widget_tweaks/tests.py
+++ b/widget_tweaks/tests.py
@@ -7,7 +7,7 @@ except ImportError:
 
 from django import VERSION
 from django import forms
-from django.forms import Form, CharField, TextInput
+from django.forms import Form, CharField, TextInput, SplitDateTimeField, SplitDateTimeWidget
 from django.template import Template, Context
 
 try:
@@ -15,6 +15,14 @@ try:
 except ImportError:
     from django.forms.extras.widgets import SelectDateWidget  # django < 2.0
 
+if VERSION[0] == 2:
+    date_time_params = dict(
+        time_attrs={'class': 'datepicker'}, date_attrs={'class': 'timepicker'}
+    )
+else:
+    date_time_params = {}
+
+
 
 # ==============================
 #       Testing helpers
@@ -33,6 +41,7 @@ class MyForm(Form):
     }))
     with_cls = CharField(widget=TextInput(attrs={'class': 'class0'}))
     date = forms.DateField(widget=SelectDateWidget(attrs={'egg': 'spam'}))
+    date_time = forms.SplitDateTimeField(widget=SplitDateTimeWidget(**date_time_params))
 
 
 def render_form(text, form=None, **context_args):
@@ -119,6 +128,12 @@ class SimpleAttrTest(TestCase):
         res = render_field('simple', 'set_data', 'key:value')
         assertIn('data-key="value"', res)
 
+    def test_widget_split(self):
+        if VERSION[0]  == 2:
+            res = render_field('date_time', 'add_class', 'validate')
+            assertIn("datepicker", res)
+            assertIn("timepicker", res)
+
 
 class ErrorsTest(TestCase):
 
@@ -314,6 +329,13 @@ class RenderFieldTagFieldReuseTest(TestCase):
         res = render_form('{{ form.simple }}{% render_field form.simple foo="bar" %}{% render_field form.simple %}')
         self.assertEqual(res.count("bar"), 1)
 
+    
+    def test_field_datetime_widget(self): #  issue #66 from github
+        if VERSION[0] == 2:
+            res = render_form('{{ form.simple }}{% render_field form.date_time class+="validate" %}')
+            self.assertEqual(res.count("timepicker"), 1, res)
+            self.assertEqual(res.count("datepicker"), 1, res)
+
     def test_field_double_rendering_simple_css(self):
         res = render_form('{% render_field form.simple %}{% render_field form.simple class+="bar" %}{% render_field form.simple class+="baz" %}')
         self.assertEqual(res.count("baz"), 1)

the pass show it clear:

test_field_datetime_widget (widget_tweaks.tests.RenderFieldTagFieldReuseTest) ... FAIL

======================================================================
FAIL: test_field_datetime_widget (widget_tweaks.tests.RenderFieldTagFieldReuseTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/zodman/apps/django-widget-tweaks/widget_tweaks/tests.py", line 336, in test_field_datetime_widget
    self.assertEqual(res.count("timepicker"), 1, res)
AssertionError: 0 != 1 : <input type="text" name="simple" required id="id_simple" /><input type="text" name="date_time_0" class="validate" required id="id_date_time_0" /><input type="text" name="date_time_1" class="validate" required id="id_date_time_1" />

[zodman]

SplitDateTimeField its a MultiWidget and not supported!