Contents
Primary Presentation
Element Catalog
servicelocator::web
Package. Belongs to the servicelocator package of the components module.
waf::view::template
The template service assembles multiple JSP pages and Web resources into a single composite view.
under the namespace waf::controller::ejb
<<SessionBean>>EJBControllerLocalEJB
This is the EJB-tier controller of the MVC. It controls all the activities that happen in a client session. It also provides mechanisms to access other session EJBs.
action
The classes in this package implement an EJB action following the command design pattern.
action::<<interface>>EJBAction
Base EJB action interface. Follows the command design pattern.
action::actions::ChangeLocaleEJBAction
- Changes the locale attribute of the StateMachine.
StateMachine
This class is a responsible for processing Events received from the client tier. Af part of the WAF framework the events are generated by web actions. The State Machine ties all EJB components together dynamically at runtime thus providing support for reusable components. This class should not be updated to handle various event types. This class will use ActionHandlers to handle events that require processing beyond the scope of this class. The mapping of the event names to handlers is managed by the JNDI key contained in the Event::getEventName() which is looked up from an environment entry located in the EJB Deployment descriptor of the EJBClientController. A second option to event handling is to do so in the XML file.
waf::event
Package that includes all the base classes that handle EJB and Web tier base events. Refinement view available.
under the namespace waf::controller::web
<<interface>>ComponentManager
Defines the services that need to be accessed from the web tier. It is loaded at startup. Can initialize objects used in the presentation tier
<<interface>>WebController
Proxy to the EJB tier that uses the EJBController LocalEJB.
action
The classes in this package implement an Web actions following the command design pattern.
action::<<interface>>HTMLAction
Interface to request handlers on the web tier
action::actions::ChangeLocaleHTMLAction
HTMLAction that processes changes in language
action::HTMLActionSupport
Empty abstract implementation of HTMLAction
DefaultComponentManager
Provides access to services in the web tier and ejb tier
DefaultWebController
Default implementation of the WebController interface.
EventMapping
Mapping between an Event and the necessary EJB Action Class
flow
Package that handles the flow of UI events from the user. Classes in this package are used and initialized through java. ServletContext
flow::<<interface>>FlowHandler
Base interface to flow handlers on the web tier.
flow::handlers:ClientStateFlowHandler
De-serializes Base64 encoded parameters encoded in web pages.
flow::ScreenFlowData
Carries the default screen and the mappings of its exceptions.
flow::ScreenFlowManager
Maps the request URL to the page for the web-templating mechanism.
MainServlet
Processes HTTP commands, like Get and Post, i.e, it matches a url to a mapping object that contains information about the current screen, the HTMLAction that is needed to process a request, and the HTMLAction that is needed to insure that the proper screen is displayed.
RequestProcessor
Web tier controller for the sample application. Processes all requests from the Main.jsp and generates the necessary data-modifying events which are sent to the WebController
Variability Guide
None
Other Information
About the Design
The WAF, Web Application Framework, provides the framework for a Model-View representation of the application. The waf::controller::web package is the view, and the waf::controller::ejb package is the model. They interact in several ways:
- Direct invocation. The ComponentManager in the view calls the EJBControllerLocalEJB directly.
- Indirect invocation. The model uses the waf::event package to receive and send messages to the view.
Events and actions are closely related:
- HTMLActions create Events. Each HTMLAction creates one type of event.
- Events carry information about the phenomena. Events do not know about actions.
- For every type of Event there can be just one unique type of EJBAction that uses it as input.
This separation promotes flexibility and scalability as it reduces the cohesion between classes and it even allows classes from other packages to "hear" this events, without changing any code in the model.
Comments in the Code
There are a couple classes with incorrect comments in the source code:
- waf::controller::web::DefaultWebController
- waf::controller::web::WebController
They both refer to an inexistent class called waf.controller.ejb.ShoppingClientControllerEJB. Apparently they forgot to update it to waf::controller::ejb::EJBControllerLocalEJB, which would still be wrong as waf::controller::web::WebController does not refer to it!!!
Related Views
- Parent. High Level Module View
- Refinement. Package waf::event
- Refinement. Package waf::view::template
- Generalization View - Package petstore