TextField Validation

you probably want to utilize the "clean()" function, which strips any nonprintable characters from input text.  If you wish to STRICTLY only support letters (not numbers, not anything else), then you can pivot to "cleanWith()", which allows you to set the list of acceptable characters.

Using this you can then choose between 2 methods:

1. easiest, sanitize the user's input as they input it.  don't bother with validaiton at all.
2. instead, you could use the funciton in your validation, and check whether the input string is different from the string when invalid characters are removed, and if so, show a validation message.

you probably want to utilize the "clean()" function, which strips any nonprintable characters from input text.  If you wish to STRICTLY only support letters (not numbers, not anything else), then you can pivot to "cleanWith()", which allows you to set the list of acceptable characters.

Using this you can then choose between 2 methods:

1. easiest, sanitize the user's input as they input it.  don't bother with validaiton at all.
2. instead, you could use the funciton in your validation, and check whether the input string is different from the string when invalid characters are removed, and if so, show a validation message.

e.g.