(Quick Reference)
nullable
Purpose
Allows a property to be set to
null. By default Grails does not allow
null values for properties.
Examples
Description
Set to
true if the property allows
null values.
This constraint influences
schema generation.
Error Code:
className.propertyName.nullable
Web requests resulting from form submissions will have blank strings, not null, for properties that have no value. Keep this in mind when doing mass property binding to properties that have been marked with nullable: true. A blank string will validate for nullable:true since the data binder will convert blank strings to null when binding to a constrained property which has been marked with nullable: true.