title: Override Default WTF forms validation for FlaskAdmin with SQLAlchemy
body: <p>It looks like the web app is still applying the default WTF Form validation, how can I disable this please? Basically the subnet field is performing my custom validation (see image1):</p>
  
  <p><a href="https://i.stack.imgur.com/FInb4.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FInb4.jpg" alt="enter image description here"></a></p>
  
  <p>However, it seems to also apply the default validation (IP Address validation) which I do not want it to do: </p>
  
  <p><a href="https://i.stack.imgur.com/9rGTG.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/9rGTG.jpg" alt="enter image description here"></a></p>
  
  <p>Please advise how I can prevent this. See the relevant code snippet below:</p>
  
  <pre><code>from sqlalchemy.dialects.postgresql import INET
   ...
   ...
   ...
  app = Flask(__name__)
   ...
   ...
  db = SQLAlchemy(app)
   ...
   ...
  
  class Ipac(db.Model):
      __tablename__ = "ipac"
      id = db.Column('id', db.Integer, primary_key=True)
      subnet = db.Column('subnet', INET)
      gateway = db.Column('gateway', INET)
      vrip = db.Column('vrip', INET)
      serverid = db.Column('serverid', db.Integer, db.ForeignKey('server.id'))
  
      def __str__(self):
          return self.subnet  
   ...
   ...
  
  class IpacView(ModelView):
      def subnet_format(form, field):
          if not re.match(r'\b(([0-9]|[0-9]{2}|2[0-5]{2}|2[0-4][0-9]|1[0-9]{2})\.){3}([0-9]|[0-9]{2}|2[0-5]{2}|2[0-4][0-9]|1[0-9]{2})\/(3[0-2]|2[0-9]|1[0-9]|[0-9])\b', field.data):
              raise ValidationError("Must be a valid subnet format!")
  
      column_display_all_relations = True
      column_labels = dict(subnet='Subnet', gateway='Gateway', vrip='VR IP')
      column_searchable_list = ('subnet', 'vrip', 'gateway', 'server.hostname')
  
      form_args = dict(
          subnet=dict(validators=[subnet_format])
          )
  
      def is_accessible(self):
          return login.current_user.is_authenticated
   ...
   ...
  </code></pre>