You are reading O'Reilly XForms Essentials by Micah Dubinko. (What is this?) - Buy XForms Essentials Online
| Allowed values:any XPath expression; the result is interpreted as a boolean. |
| Default value:false |
This property signals whether a value is required in this node for the form to be considered valid. A node satisfies the required condition when it is convertible into a string with one or more characters.
Form controls take a hint from the required property. Form controls are required to distinguish between valid and invalid states, and satisfying this property is a part of validity.