User interface components must contain all the information necessary to create and process the view and may also include methods for interacting with the controller and model functions. Definition of the following may be required to create a user interface component:
Acquire and display data.
Recognize and interpret events triggered by both users and the system.
Filter actions based upon the context.
Prevent triggering transactions outside the specified events.
Validate user inputs.
Maintain reference of the state with the controller.
Maintain reference of the state with the model and update display when the model changes.
Implement local caching.
Implement features for pagination when dealing with long lists. ...