How do I add special Character constraint to MFXPasswordField

[goatfanboi23]

I want the user to have to enter special characters in their password. I am able to a constraint of the number of characters with the following code: passwordField.getValidator().constraint("The password must be at least 8 characters long", passwordField.textProperty().length().greaterThanOrEqualTo(8));. I can not figure out how to create my own BooleanExpression constraint.
-Thanks

[palexdev]

@goatfanboi23 There's a full example here Demo