This class implements many rules for validating text field values.
It can be used to validate field values submitted using Web forms.
It can return a validation summary report using customizable error messages style.
Currently it supports the following validation types:
- Numeric within a range
- Regular expression match
- Email address
- Date
- Comparison of two field values,
- Text with a minimum and maximum length
- Custom for user-defined validation
Each text field value may be required or not and have associated individual error messages.