old_contents: from flask_wtf import Form
  from wtforms.fields import (TextField, SubmitField, BooleanField, DateField,
                              DateTimeField)
  from wtforms.validators import Required
  
  
  class SignupForm(Form):
      name = TextField(u'Your name', validators=[Required()])
      birthday = DateField(u'Your birthday')
      now = DateTimeField(u'Current time',
                          description='...for no particular reason')
      eula = BooleanField(u'I did not read the terms and conditions',
                          validators=[Required('You must agree to not agree!')])
      submit = SubmitField(u'Signup')
  
new_contents: from flask_wtf import Form
  from wtforms.fields import (TextField, SubmitField, BooleanField, DateField,
                              DateTimeField)
  from wtforms.validators import Required, Email
  
  
  class SignupForm(Form):
      name = TextField(u'Your name', validators=[Required()])
      email = TextField(u'Your email address', validators=[Email()])
      birthday = DateField(u'Your birthday')
      now = DateTimeField(u'Current time',
                          description='...for no particular reason')
      eula = BooleanField(u'I did not read the terms and conditions',
                          validators=[Required('You must agree to not agree!')])
      submit = SubmitField(u'Signup')
  
subject: Add email field to sample app.