Methods and apparatus for displaying objects in client GUI. A lead selection and scoping information is used to determine whether the object is viewable, and the object is rendered only if it is at least partially viewable. The lead selection and scoping information is used to determine whether data is needed to render the object, and data is received from a corresponding object on a server only if it is needed to render the object. Determining whether the object is viewable in the GUI can be based on declaratively marked entities within the object's view and on view calculation rules. Determining whether data is needed to render the object can be based on declaratively marked entities within the object's data model such as flags indicating whether the data field is valid or whether the binding of the data field to a data source is valid.