A portlet mode indicates the function a portlet is performing. Normally, portlets perform

different tasks and create different content depending on the function they are currently

performing. A portlet mode advises the portlet what task it should perform and what

content it should generate. When invoking a portlet, the portlet container provides the

current portlet mode to the portlet. Portlets can programmatically change their portlet

mode when processing an action request.

The Portlet Specification defines three portlet modes, VIEW, EDIT, and HELP.

A design tip can be  put all business logic related to VIEW mode in a method called doView(), and business logic related to the configuration of the application in a doEdit() method, and help-related logic in a doHelp()