WTForms - DateTimeLocalField data is None after submit

Question

After form is submitted with a POST request, every Field data has its value, except DateTimeLocalField. Accessing DateTimeLocalField's data value is a type of None.

Form

class ArticleForm(FlaskForm):
    name = StringField('Name', validators=[DataRequired()])
    category = SelectField(u'Category', choices=categories.choices)
    town = StringField('Town', validators=[DataRequired()])
    minimal_price = IntegerField('Minimal price')
    article_image = FileField('Article_image', validators=[FileRequired()])
    time_left = DateTimeLocalField('Time to end', validators=[InputRequired()],
                              format='%Y-%m-%d %H:%M:%S')
    description = TextAreaField('Description', validators=[DataRequired()])

Validation: (tested with is_submitted, all work except for article_form.time_left.data which is None)

if article_form.validate_on_submit():

    new_article = Article(name=article_form.name.data,
                          category=article_form.category.data,
                          town=article_form.town.data,
                          minimal_price=article_form.minimal_price.data,
                          article_image=name,
                          time_left=article_form.time_left.data, # <-- None
                          description=article_form.description.data,
                          user_id=current_user.id)

Any help to get data from DateTimeLocalField ?

Answer 1

Try changing the format of the DateTimeLocalField from

format='%Y-%m-%d %H:%M:%S' 

to:

format='%Y-%m-%dT%H:%M'

Tip: you can print the actual content of the input field prior to the validation to confirm the correct formatting of the DateTimeLocalField field.

Answer 2

Use wtforms.fields.html5.DateTimeLocalField instead of wtforms.DateTimeLocalField. Set the format with date and time separated by a 'T'. If you would want the current time as the default value, set default parameter.

from wtforms.fields.html5 import DateTimeLocalField

class InterviewForm(Form):
    posted = DateTimeLocalField('Posted:', default=datetime.today, format='%Y-%m-%dT%H:%M')