WEBUI has datetime widgets

only used in "single" kind, and not supported in Chrome. But still!
refs #35

larigira/timeform_single.py

@@ -1,15 +1,48 @@
 from datetime import datetime
 
 from flask_wtf import Form
-from wtforms import StringField, DateTimeField, validators, SubmitField
+from wtforms import StringField, Field, validators, SubmitField
+import wtforms.widgets
+
+
+class DateTimeInput(wtforms.widgets.Input):
+    input_type = 'datetime-local'
+
+
+class EasyDateTimeField(Field):
+    '''
+    a "fork" of DateTimeField which uses HTML5 datetime-local
+    The format is not customizable, because it is imposed by the HTML5 specification
+    '''
+    widget = DateTimeInput()
+
+    def __init__(self, label=None, validators=None, **kwargs):
+        super(EasyDateTimeField, self).__init__(label, validators, **kwargs)
+        self.format = '%Y-%m-%dT%H:%M:%S'
+
+    def _value(self):
+        if self.raw_data:
+            return ' '.join(self.raw_data)
+        else:
+            return self.data and self.data.strftime(self.format) or ''
+
+    def process_formdata(self, valuelist):
+        if valuelist:
+            date_str = ' '.join(valuelist)
+            try:
+                self.data = datetime.strptime(date_str, self.format)
+            except ValueError:
+                self.data = None
+                raise ValueError(self.gettext('Not a valid datetime value <tt>{}</tt>').format(date_str))
+
 
 
 class SingleAlarmForm(Form):
     nick = StringField('Alarm nick', validators=[validators.required()],
                        description='A simple name to recognize this alarm')
-    dt = DateTimeField('Date and time', validators=[validators.required()],
+    dt = EasyDateTimeField('Date and time', validators=[validators.required()],
                        description='Date to ring on, expressed as '
-                       'YYYY-MM-DD HH:MM:SS')
+                       '2000-12-31T13:42:00')
     submit = SubmitField('Submit')
 
     def populate_from_timespec(self, timespec):