What are Flask validators and how do I use them?

What are Flask validators and how do I use them?

Flask validators are tools used to validate form data in Flask applications. They help ensure that the data submitted by users meets certain criteria.

Can you give me an example of how to implement a validator in Flask?

Sure! You can use the Flask-WTF extension. For example, to validate an email, you can use the Email validator like this:

from flask_wtf import FlaskForm
from wtforms import StringField
from wtforms.validators import DataRequired, Email

class MyForm(FlaskForm):
    email = StringField('Email', validators=[DataRequired(), Email()])

What happens if the validation fails?

If validation fails, Flask-WTF will raise a validation error, and you can display the error messages to the user, prompting them to correct their input.

Are there other types of validators I can use?

Yes, there are many validators available, such as Length, NumberRange, and EqualTo for confirming passwords. You can combine them as needed.