public ValueList getValues ( PExp exp , ObjectContext ctxt ) { try { return exp . apply ( af . getExpressionValueCollector ( ) , ctxt ) ; // FIXME: should we handle exceptions like this } catch ( AnalysisException e ) { return null ; // Most have none } }
Return a list of all the updatable values read by the expression . This is used to add listeners to values that affect permission guards so that the guard may be efficiently re - evaluated when the values change .