oracle.cabo.servlet.event
Class BasePageFlowEngine

java.lang.Object
  |
  +--oracle.cabo.servlet.event.BasePageFlowEngine

All Implemented Interfaces:

PageFlowEngine

Direct Known Subclasses:

TrivialPageFlowEngine

public abstract class BasePageFlowEngine

extends java.lang.Object

implements PageFlowEngine

Base implementation of PageFlowEngine.

Field Summary

static java.lang.String	FORWARD_EVENT_PROPERTY Page property constant for specifying an event string.
static java.lang.String	FORWARD_PAGE_PROPERTY Page property constant attached to the login page when redirecting to it.

Constructor Summary

BasePageFlowEngine()

Method Summary

protected EventResult	checkPageAccess(BajaContext context, Page sourcePage, PageEvent event) Verifies that the current page can be accessed.
void	destroy() Destroys the page flow engine, freeing any state as needed.
protected abstract Page	getPage(BajaContext context, Page sourcePage, PageEvent event, EventResult result) Given the result of an event, determine which Page should be rendered.
Page	handleRequest(BajaContext context, Page sourcePage, PageEvent event, EventHandler handler) Handles a request for a page.
void	init(javax.servlet.Servlet servlet, javax.servlet.ServletConfig config) Initializes the page flow engine.
protected Page	processForwardRequest(BajaContext context, Page sourcePage, Page targetPage) Processes any forward request on the original source page.
static void	setForwardRequest(BajaContext context, Page targetPage, Page forwardPage, PageEvent forwardEvent) Attaches a forwarding request to a page.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

FORWARD_PAGE_PROPERTY

public static final java.lang.String FORWARD_PAGE_PROPERTY

Page property constant attached to the login page when redirecting to it.

FORWARD_EVENT_PROPERTY

public static final java.lang.String FORWARD_EVENT_PROPERTY

Page property constant for specifying an event string. This property is attached to the login page when redirecting to it, if the redirected request includes an event. The value is in query string format - ie. "event=eventname¶m1=val1¶m2=val2"

Constructor Detail

BasePageFlowEngine

public BasePageFlowEngine()

Method Detail

setForwardRequest

public static void setForwardRequest(BajaContext context,
                                     Page targetPage,
                                     Page forwardPage,
                                     PageEvent forwardEvent)

Attaches a forwarding request to a page. This is used to indicate that the target page should render on this pass, but events fired from that target page should lead to the "forwardPage" page.

init

public void init(javax.servlet.Servlet servlet,
                 javax.servlet.ServletConfig config)

Initializes the page flow engine. Developers should not call this method; PageBroker will call it automatically.

Specified by:

init in interface PageFlowEngine

destroy

public void destroy()

Destroys the page flow engine, freeing any state as needed. Developers should not call this method; PageBroker will call it automatically.

Specified by:

destroy in interface PageFlowEngine

handleRequest

public Page handleRequest(BajaContext context,
                          Page sourcePage,
                          PageEvent event,
                          EventHandler handler)
                   throws PageEventException

Handles a request for a page.

Specified by:

handleRequest in interface PageFlowEngine

Parameters:

context - the current BajaContext

sourcePage - the page of the request

event - the event being fired on that page

handler - the EventHandler that should process the event

Returns:

the page that should be rendered in response

checkPageAccess

protected EventResult checkPageAccess(BajaContext context,
                                      Page sourcePage,
                                      PageEvent event)

Verifies that the current page can be accessed. If it can, the method must return null. Otherwise, it should return an EventResult that will be interpreted to determine the page to forward to.

getPage

protected abstract Page getPage(BajaContext context,
                                Page sourcePage,
                                PageEvent event,
                                EventResult result)
                         throws PageEventException

Given the result of an event, determine which Page should be rendered. It is assumed that the sourcePage is considered acceptable - that is, checkPageAccess() would accept it. It is also assumed that the page returned is also acceptable.

Parameters:

context - the current BajaContext

sourcePage - the page on which the event was processed

event - the event just processed

result - the result of that event

processForwardRequest

protected Page processForwardRequest(BajaContext context,
                                     Page sourcePage,
                                     Page targetPage)
                              throws PageEventException

Processes any forward request on the original source page.

Parameters:

context - the current BajaContext

sourcePage - the page on with the event was processed

targetPage - the presumed target page

Returns:

the correct page to display