If I understand you correctly and you want to retrieve the value of the the attribute you selected (MxObjectMember), you could pass your current object and the MxObjectMember to a java action with :
You do have to specify which datatype you would like to return from the java action. In the example I used string. You need to add some type checking if you want to return other datatypes.
public class Java_action extends UserAction<String>
{
private IMendixObject myObject;
private IMendixObject __targetMxObjectMember;
private mxmodelreflection.proxies.MxObjectMember targetMxObjectMember;
public Java_action(IMendixObject myObject, IMendixObject targetMxObjectMember)
{
super();
this.myObject = myObject;
this.__targetMxObjectMember = targetMxObjectMember;
}
@Override
public String executeAction() throws Exception
{
this.targetMxObjectMember = __targetMxObjectMember == null ? null : mxmodelreflection.proxies.MxObjectMember.initialize(getContext(), __targetMxObjectMember);
// BEGIN USER CODE
return this.myObject.getValue(getContext(), targetMxObjectMember.getAttributeName()).toString();
// END USER CODE
}