Date related field can handle several formats

src/wtforms/fields/datetime.py

@@ -15,7 +15,10 @@
 
 class DateTimeField(Field):
     """
-    A text field which stores a `datetime.datetime` matching a format.
+    A text field which stores a :class:`datetime.datetime` matching one or
+    several formats. If ``format`` is a list, any input value matching any
+    format will be accepted, and the first format in the list will be used
+    to produce HTML values.
     """
 
     widget = widgets.DateTimeInput()
@@ -24,29 +27,33 @@ def __init__(
         self, label=None, validators=None, format="%Y-%m-%d %H:%M:%S", **kwargs
     ):
         super().__init__(label, validators, **kwargs)
-        self.format = format
-        self.strptime_format = clean_datetime_format_for_strptime(format)
+        self.format = format if isinstance(format, list) else [format]
+        self.strptime_format = clean_datetime_format_for_strptime(self.format)
 
     def _value(self):
         if self.raw_data:
             return " ".join(self.raw_data)
-        return self.data and self.data.strftime(self.format) or ""
+        return self.data and self.data.strftime(self.format[0]) or ""
 
     def process_formdata(self, valuelist):
         if not valuelist:
             return
 
         date_str = " ".join(valuelist)
-        try:
-            self.data = datetime.datetime.strptime(date_str, self.strptime_format)
-        except ValueError as exc:
-            self.data = None
-            raise ValueError(self.gettext("Not a valid datetime value.")) from exc
+        for format in self.strptime_format:
+            try:
+                self.data = datetime.datetime.strptime(date_str, format)
+                return
+            except ValueError:
+                self.data = None
+
+        raise ValueError(self.gettext("Not a valid datetime value."))
 
 
 class DateField(DateTimeField):
     """
-    Same as DateTimeField, except stores a `datetime.date`.
+    Same as :class:`~wtforms.fields.DateTimeField`, except stores a
+    :class:`datetime.date`.
     """
 
     widget = widgets.DateInput()
@@ -59,18 +66,20 @@ def process_formdata(self, valuelist):
             return
 
         date_str = " ".join(valuelist)
-        try:
-            self.data = datetime.datetime.strptime(
-                date_str, self.strptime_format
-            ).date()
-        except ValueError as exc:
-            self.data = None
-            raise ValueError(self.gettext("Not a valid date value.")) from exc
+        for format in self.strptime_format:
+            try:
+                self.data = datetime.datetime.strptime(date_str, format).date()
+                return
+            except ValueError:
+                self.data = None
+
+        raise ValueError(self.gettext("Not a valid date value."))
 
 
 class TimeField(DateTimeField):
     """
-    Same as DateTimeField, except stores a `time`.
+    Same as :class:`~wtforms.fields.DateTimeField`, except stores a
+    :class:`datetime.time`.
     """
 
     widget = widgets.TimeInput()
@@ -83,19 +92,20 @@ def process_formdata(self, valuelist):
             return
 
         time_str = " ".join(valuelist)
-        try:
-            self.data = datetime.datetime.strptime(
-                time_str, self.strptime_format
-            ).time()
-        except ValueError as exc:
-            self.data = None
-            raise ValueError(self.gettext("Not a valid time value.")) from exc
+        for format in self.strptime_format:
+            try:
+                self.data = datetime.datetime.strptime(time_str, format).time()
+                return
+            except ValueError:
+                self.data = None
+
+        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`.
+    Same as :class:`~wtforms.fields.DateField`, except represents a month,
+    stores a :class:`datetime.date` with `day = 1`.
     """
 
     widget = widgets.MonthInput()
@@ -106,7 +116,12 @@ def __init__(self, label=None, validators=None, format="%Y-%m", **kwargs):
 
 class DateTimeLocalField(DateTimeField):
     """
-    Represents an ``<input type="datetime-local">``.
+    Same as :class:`~wtforms.fields.DateTimeField`, but represents an
+    ``<input type="datetime-local">``.
     """
 
     widget = widgets.DateTimeLocalInput()
+
+    def __init__(self, *args, **kwargs):
+        kwargs.setdefault("format", ["%Y-%m-%d %H:%M:%S", "%Y-%m-%dT%H:%M:%S"])
+        super().__init__(*args, **kwargs)

src/wtforms/utils.py

@@ -18,14 +18,19 @@
 )
 
 
-def clean_datetime_format_for_strptime(format):
+def clean_datetime_format_for_strptime(formats):
     """
     Remove dashes used to disable zero-padding with strftime formats (for
     compatibiltity with strptime).
     """
-    return re.sub(
-        _DATETIME_STRIP_ZERO_PADDING_FORMATS_RE, lambda m: m[0].replace("-", ""), format
-    )
+    return [
+        re.sub(
+            _DATETIME_STRIP_ZERO_PADDING_FORMATS_RE,
+            lambda m: m[0].replace("-", ""),
+            format,
+        )
+        for format in formats
+    ]
 
 
 class UnsetValue:

tests/fields/test_datetime.py

@@ -57,3 +57,14 @@ def test_microseconds():
     F = make_form(a=DateTimeField(format="%Y-%m-%d %H:%M:%S.%f"))
     form = F(DummyPostData(a=["2011-05-07 03:23:14.4242"]))
     assert d == form.a.data
+
+
+def test_multiple_formats():
+    d = datetime(2020, 3, 4, 5, 6)
+    F = make_form(a=DateTimeField(format=["%Y-%m-%d %H:%M", "%Y%m%d%H%M"]))
+
+    form = F(DummyPostData(a=["2020-03-04 05:06"]))
+    assert d == form.a.data
+
+    form = F(DummyPostData(a=["202003040506"]))
+    assert d == form.a.data

tests/fields/test_datetimelocal.py

@@ -0,0 +1,72 @@
+from datetime import datetime
+
+from tests.common import DummyPostData
+
+from wtforms.fields import DateTimeLocalField
+from wtforms.form import Form
+
+
+def make_form(name="F", **fields):
+    return type(str(name), (Form,), fields)
+
+
+class F(Form):
+    a = DateTimeLocalField()
+    b = DateTimeLocalField(format="%Y-%m-%d %H:%M")
+    c = DateTimeLocalField(format="%-m/%-d/%Y %-I:%M")
+
+
+def test_basic():
+    d = datetime(2008, 5, 5, 4, 30, 0, 0)
+    # Basic test with both inputs
+    form = F(
+        DummyPostData(
+            a=["2008-05-05", "04:30:00"], b=["2008-05-05 04:30"], c=["5/5/2008 4:30"]
+        )
+    )
+    assert form.a.data == d
+    assert (
+        form.a()
+        == '<input id="a" name="a" type="datetime-local" value="2008-05-05 04:30:00">'
+    )
+    assert form.b.data == d
+    assert (
+        form.b()
+        == '<input id="b" name="b" type="datetime-local" value="2008-05-05 04:30">'
+    )
+    assert form.c.data == d
+    assert (
+        form.c()
+        == '<input id="c" name="c" type="datetime-local" value="5/5/2008 4:30">'
+    )
+    assert form.validate()
+
+    # Test with a missing input
+    form = F(DummyPostData(a=["2008-05-05"]))
+    assert not form.validate()
+    assert form.a.errors[0] == "Not a valid datetime value."
+
+    form = F(a=d, b=d, c=d)
+    assert form.validate()
+    assert form.a._value() == "2008-05-05 04:30:00"
+    assert form.b._value() == "2008-05-05 04:30"
+    assert form.c._value() == "5/5/2008 4:30"
+
+
+def test_microseconds():
+    d = datetime(2011, 5, 7, 3, 23, 14, 424200)
+    F = make_form(a=DateTimeLocalField(format="%Y-%m-%d %H:%M:%S.%f"))
+    form = F(DummyPostData(a=["2011-05-07 03:23:14.4242"]))
+    assert d == form.a.data
+
+
+def test_separators():
+    dt = datetime(2008, 5, 5, 4, 30, 0, 0)
+
+    form = F(DummyPostData(a=["2008-05-05 04:30:00"]))
+    assert form.a.data == dt
+    assert form.validate()
+
+    form = F(DummyPostData(a=["2008-05-05T04:30:00"]))
+    assert form.a.data == dt
+    assert form.validate()