Menu
I have an application in Python Flask, where a username field has a validation on length. I would also like to prevent spaces within the username. How could I achieve that?
class RegistrationForm(Form):
username = TextField('Username', [validators.Length(min=4, max=25)])
email = TextField('Email Address', [validators.Email(message='Invalid email address.')])
811
to validate the data, call the validate() method, which will return True if the data validates, False otherwise.
The validate_on_submit() method of the form returns True when the form was submitted and the data was accepted by all the field validators. In all other cases, validate_on_submit() returns False . The return value of this method effectively serves to determine whether the form needs to be rendered or processed.
Flask WTForms is a library that makes form handling easy and structured. It also ensures the effective handling of form rendering, validation, and security. To build forms with this approach, you start by creating a new file in our app directory and name it forms.py. This file will contain all the application forms.
Instead, pass required=True , which will set a bare attribute on the tag. Check the flags on a field to see if a Required validator was set: field. flags. required is a boolean.
You should be able to ensure that using the Regexp validator. I use the regex Django uses for the username form:
username = TextField('Username', [validators.Regexp(r'^[\w.@+-]+$'), validators.Length(min=4, max=25)])
This allows alphanumeric characters, dots, @, + and -. You can of course just use \w for alphanumeric characters.
122
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
