I have a dropdown list with enum values. When the dropdownlist is hidden by ng-show, the value is still be submitted as ''. So i getting 

org.codehaus.jackson.map.JsonMappingException: Can not construct instance of MyEnum from String value '': value not one of declared Enum instance names
 at [Source: com.ibm.ws.webcontainer.srt.http.HttpInputStream@1024cb7e; line: 1, column: 349]

How do I skip the validation/submission?

`<select ng-show="itIsHideNow()" ng-model="value.myEnum"
 ng-options="option for option in myEnumOptions">
 </select>`