FieldState is a visual state handler for form fields where the required/available state of a field depends on other factors - for example the values/selections of other fields.
At its heart FieldState saves you writing lots of code to control which fields suddenly become available/required based on user input in other fields. FieldState handles this via a simple, HTML5 data attributes-based API (with a JavaScript API for deeper usage).
Formore complex evaluations, FieldState supports regular expressions, callbacks, multi-field conditional chaining and various types of event.