Implemented MonthField

CHANGES.rst

@@ -1,5 +1,12 @@
 .. currentmodule:: wtforms
 
+Version 2.x.x
+-------------
+
+Unreleased
+
+-   Implemented :class:`~wtforms.fields.core.MonthField`. :pr:`530` :pr:`593`
+
 
 Version 2.3.1
 -------------

docs/fields.rst

@@ -582,6 +582,8 @@ namespace and can be overridden or modified just like any other widget.
 
 .. autoclass:: DateField(default field arguments, format='%Y-%m-%d')
 
+.. autoclass:: MonthField(default field arguments, format='%Y-%m')
+
 .. autoclass:: TimeField(default field arguments, format='%H:%M')
 
 .. autoclass:: DateTimeLocalField(default field arguments, format='%Y-%m-%d %H:%M:%S')

tests/fields.py

@@ -657,6 +657,29 @@ def test_failure(self):
         self.assertEqual(form.a.process_errors[0], 'Not a valid date value')
 
 
+class TestDateField(TestCase):
+    class F(Form):
+        a = MonthField()
+        b = MonthField(format='%m/%Y')
+
+    def test_basic(self):
+        d = date(2008, 5, 1)
+        form = self.F(DummyPostData(a=['2008-05'], b=['05/2008']))
+
+        assert d == form.a.data
+        assert '2008-05' == form.a._value()
+
+        assert d == form.b.data
+
+    def test_failure(self):
+        form = self.F(DummyPostData(a=['2008-bb']))
+
+        assert not form.validate()
+        assert 1 == len(form.a.process_errors)
+        assert 1 == len(form.a.errors)
+        assert 'Not a valid date value' == form.a.process_errors[0]
+
+
 class TimeFieldTest(TestCase):
     class F(Form):
         a = TimeField()
@@ -962,6 +985,7 @@ class F(Form):
         email = html5.EmailField()
         datetime = html5.DateTimeField()
         date = html5.DateField()
+        month = html5.MonthField()
         dt_local = html5.DateTimeLocalField()
         integer = html5.IntegerField()
         decimal = html5.DecimalField()
@@ -989,6 +1013,7 @@ def test_simple(self):
             b('email', 'foo@bar.com', 'type="email"'),
             b('datetime', '2013-09-05 00:23:42', 'type="datetime"', datetime(2013, 9, 5, 0, 23, 42)),
             b('date', '2013-09-05', 'type="date"', date(2013, 9, 5)),
+            b('month', '2014-05', 'type="month"', date(2014, 5, 1)),
             b('dt_local', '2013-09-05 00:23:42', 'type="datetime-local"', datetime(2013, 9, 5, 0, 23, 42)),
             b('integer', '42', '<input id="integer" name="integer" type="number" value="42">', 42),
             b('decimal', '43.5', '<input id="decimal" name="decimal" step="any" type="number" value="43.5">', Decimal('43.5')),

wtforms/fields/core.py

@@ -19,7 +19,7 @@
 __all__ = (
     'BooleanField', 'DecimalField', 'DateField', 'DateTimeField', 'FieldList',
     'FloatField', 'FormField', 'IntegerField', 'RadioField', 'SelectField',
-    'SelectMultipleField', 'StringField', 'TimeField',
+    'SelectMultipleField', 'StringField', 'TimeField', 'MonthField',
 )
 
 
@@ -827,6 +827,15 @@ def process_formdata(self, valuelist):
                 raise ValueError(self.gettext('Not a valid time value'))
 
 
+class MonthField(DateField):
+    """
+    Same as DateField, except represents a month, stores a `datetime.date` with `day = 1`.
+    """
+
+    def __init__(self, label=None, validators=None, format="%Y-%m", **kwargs):
+        super(MonthField, self).__init__(label, validators, format, **kwargs)
+
+
 class FormField(Field):
     """
     Encapsulate a form as a field in another form.

wtforms/fields/html5.py

@@ -60,6 +60,13 @@ class TimeField(core.TimeField):
     widget = widgets.TimeInput()
 
 
+class MonthField(core.MonthField):
+    """
+    Represents an ``<input type="month">``.
+    """
+    widget = widgets.MonthInput()
+
+
 class DateTimeLocalField(core.DateTimeField):
     """
     Represents an ``<input type="datetime-local">``.