public Void addFields(List<String> fieldNames)
Type: Void
This method should be called before a record has been loaded—typically, it's called by the controller's constructor. If this method is called outside of the constructor, you must use the reset() method before calling addFields().
The strings in fieldNames can either be the API name of a field, such as AccountId, or they can be explicit relationships to fields, such as something__r.myField__c.
This method is only for controllers used by dynamicVisualforce bindings.