org.apache.beehive.netui.pageflow
Class PageFlowController

Object
  PageFlowManagedObject
      FlowController
          PageFlowController

All Implemented Interfaces:

Serializable, EventListener, HttpSessionBindingListener, ActionResolver, InternalConstants, PageFlowConstants

public abstract class PageFlowController
extends FlowController
implements InternalConstants

Base class for controller logic, exception handlers, and state associated with a particular web directory path. The class is configured through the @Jpf.Controller annotation.

When a page flow request (the page flow URI itself, or any ".do" or page URI in the directory path), arrives, an instance of the associated PageFlowController class is set as the current page flow, and remains stored in the session until a different one becomes active ("long lived" page flows stay in the session indefinitely; see longLived on @Jpf.Controller).

The page flow class handles actions that are most commonly raised by user interaction with pages. The actions are handled by action methods or action annotations that determine the next URI to be displayed, after optionally performing arbitrary logic.

If the PageFlowController is a "nested page flow" (nested is set to true on @Jpf.Controller), then this is a reusable, modular flow that can be "nested" during other flows. It has entry points (actions with optional form bean arguments), and exit points (@Jpf.Forward, @Jpf.SimpleAction, or @Jpf.ConditionalForward annotations that have returnAction attributes).

The page flow class also handles exceptions thrown by actions or during page execution (see catches on @Jpf.Controller). Unhandled exceptions are handled in order by declared SharedFlowControllers (see sharedFlowRefs on @Jpf.Controller).

Properties in the current page flow instance can be accessed from JSP 2.0-style expressions like this one: ${pageFlow.someProperty}.

There may only be one page flow in any package.

See Also:

SharedFlowController, Serialized Form

PageFlowController

protected PageFlowController()

Default constructor.

getModulePath

public String getModulePath()

Get the Struts module path for this page flow.

Specified by:

getModulePath in interface ActionResolver

Specified by:

getModulePath in class FlowController

Returns:

a String that is the Struts module path for this controller, and which is also the directory path from the web application root to this PageFlowController (not including the action filename).

getURI

public String getURI()

Get the URI for addressing this PageFlowController.

Specified by:

getURI in interface ActionResolver

Returns:

a String that is the URI which will execute the begin action on this PageFlowController.

isNestable

protected boolean isNestable()

Tell whether this PageFlowController can be "nested", i.e., if it can be invoked from another page flow with the intention of returning to the original one. Page flows are declared to be nested by specifying nested=true on the @Jpf.Controller annotation.

Returns:

true if this PageFlowController can be nested.

isLongLived

protected boolean isLongLived()

Tell whether this is a "long lived" page flow. Once it is invoked, a long lived page flow is never removed from the session unless FlowController.remove() is called. Navigating to another page flow hides the current long lived controller, but does not remove it.

removeFromSession

protected void removeFromSession(HttpServletRequest request)

Remove this instance from the session. When inside a page flow action, FlowController.remove() may be called instead.

Specified by:

removeFromSession in class PageFlowManagedObject

isPageFlow

public boolean isPageFlow()

Tell whether this is a PageFlowController.

Specified by:

isPageFlow in interface ActionResolver

Overrides:

isPageFlow in class FlowController

Returns:

true.

persistInSession

public void persistInSession(HttpServletRequest request,
                             HttpServletResponse response)

Store this object in the user session, in the appropriate place. Used by the framework; normally should not be called directly.

Specified by:

persistInSession in class PageFlowManagedObject

ensureFailover

public void ensureFailover(HttpServletRequest request)

Ensures that any changes to this object will be replicated in a cluster (for failover), even if the replication scheme uses a change-detection algorithm that relies on HttpSession.setAttribute to be aware of changes. Note that this method is used by the framework and does not need to be called explicitly in most cases.

Specified by:

ensureFailover in class PageFlowManagedObject

Parameters:

request - the current HttpServletRequest

internalExecute

protected ActionForward internalExecute(ActionMapping mapping,
                                        ActionForm form,
                                        HttpServletRequest request,
                                        HttpServletResponse response)
                                 throws Exception

Description copied from class: FlowController

An internal method for executing an action; should not be invoked directly.

Overrides:

internalExecute in class FlowController

Throws:

Exception

getSharedFlows

public Map getSharedFlows()

Get the a map of shared flow name to shared flow instance.

Returns:

a Map of shared flow name (string) to shared flow instance (SharedFlowController).

getSharedFlow

public SharedFlowController getSharedFlow(String sharedFlowName)

Get a shared flow, based on its name as defined in this page flow's sharedFlowRefs attribute on @Jpf.Controller. To retrieve any shared flow based on its class name, use PageFlowUtils.getSharedFlow(java.lang.String, javax.servlet.http.HttpServletRequest).

Parameters:

sharedFlowName - the name of the shared flow, as in this page flows's sharedFlowRefs attribute on the @Jpf.Controller annotation.

Returns:

the SharedFlowController with the given name.

removeSharedFlow

public void removeSharedFlow(String sharedFlowName)

Remove a shared flow from the session, based on its name as defined in this page flow's sharedFlowRefs attribute on @Jpf.Controller. To remove any shared flow based on its class name, use PageFlowUtils.removeSharedFlow(java.lang.String, javax.servlet.http.HttpServletRequest).

Parameters:

sharedFlowName - the name of the shared flow, as in this page flows's sharedFlowRefs attribute on the @Jpf.Controller annotation.

create

public final void create(HttpServletRequest request,
                         HttpServletResponse response,
                         ServletContext servletContext)

This is a framework method for initializing a newly-created page flow, and should not normally be called directly.

Overrides:

create in class FlowController

getTaxonomy

protected String getTaxonomy()

Get the "resource taxonomy": a period-separated list that starts with the current web application name, continues through all of this PageFlowController's parent directories, and ends with this PageFlowController's class name.

getPreviousForm

protected ActionForm getPreviousForm()

Deprecated. This method may return an ActionForm wrapper when the form bean type does not extend ActionForm. Use getPreviousFormBean() instead.

Get the submitted form bean from the most recent action execution in this PageFlowController.

Note: if the current page flow does not contain a @Jpf.Forward or a @Jpf.SimpleAction with navigateTo=Jpf.NavigateTo.previousAction, then this method will always return null by default. To enable it in this situation, add the following method to the page flow:

protected boolean alwaysTrackPreviousAction()
{
    return true;
}


Returns:

the ActionForm instance from the most recent action execution, or null if there was no form bean submitted.

See Also:

getPreviousPageInfo(), getCurrentPageInfo(), getPreviousActionInfo(), getPreviousActionURI(), getPreviousForwardPath(), getCurrentForwardPath()

getPreviousFormBean

protected Object getPreviousFormBean()

Get the submitted form bean from the most recent action execution in this PageFlowController.

Note: if the current page flow does not contain a @Jpf.Forward or a @Jpf.SimpleAction with navigateTo=Jpf.NavigateTo.previousAction, then this method will always return null by default. To enable it in this situation, add the following method to the page flow:

protected boolean alwaysTrackPreviousAction()
{
    return true;
}


Returns:

the form bean instance from the most recent action execution, or null if there was no form bean submitted.

See Also:

getPreviousPageInfo(), getCurrentPageInfo(), getPreviousActionInfo(), getPreviousActionURI(), getPreviousForwardPath(), getCurrentForwardPath()

getPreviousActionURI

protected String getPreviousActionURI()

Get the URI for the most recent action in this PageFlowController.

Note: if the current page flow does not use a @Jpf.Forward, @Jpf.SimpleAction, or @Jpf.ConditionalForward with navigateTo=previousAction, then this method will always return null by default. To enable it in this situation, add the following method to the page flow:

protected boolean alwaysTrackPreviousAction()
{
    return true;
}


Returns:

a String that is the most recent URI.

See Also:

getPreviousPageInfo(), getCurrentPageInfo(), getPreviousActionInfo(), getPreviousFormBean(), getPreviousForwardPath(), getCurrentForwardPath()

getCurrentForwardPath

public String getCurrentForwardPath()

Get the webapp-relative URI for the most recent page (in this page flow) shown to the user.

Note: if the current page flow does not use a @Jpf.Forward, @Jpf.SimpleAction, or @Jpf.ConditionalForward with navigateTo=currentPage or navigateTo=previousPage, then this method will always return null by default. To enable it in this situation, add the following method to the page flow:

protected boolean alwaysTrackPreviousPage()
{
    return true;
}


Returns:

a String that is the URI path for the most recent page shown to the user.

See Also:

getPreviousPageInfo(), getCurrentPageInfo(), getPreviousActionInfo(), getPreviousActionURI(), getPreviousFormBean(), getPreviousForwardPath()

getPreviousForwardPath

protected String getPreviousForwardPath()

Get the webapp-relative URI for the previous page (in this page flow) shown to the user. The previous page is the one shown before the most recent page.

Note: if the current page flow does not use a @Jpf.Forward, @Jpf.SimpleAction, or @Jpf.ConditionalForward with navigateTo=currentPage or navigateTo=previousPage, then this method will always return null by default. To enable it in this situation, add the following method to the page flow:

protected boolean alwaysTrackPreviousPage()
{
    return true;
}


Returns:

a String that is the URI path for the previous page shown to the user.

See Also:

getPreviousPageInfo(), getCurrentPageInfo(), getPreviousActionInfo(), getPreviousActionURI(), getPreviousFormBean(), getCurrentForwardPath()

getPreviousPageInfoLegacy

public final PreviousPageInfo getPreviousPageInfoLegacy(PageFlowController curJpf,
                                                        HttpServletRequest request)

Deprecated. This method will be removed without replacement in a future release.

Get a legacy PreviousPageInfo.

Specified by:

getPreviousPageInfoLegacy in class FlowController

getCurrentPageInfo

public final PreviousPageInfo getCurrentPageInfo()

Get information about the most recent page (in this page flow) shown to the user.

Note: if the current page flow does not use a @Jpf.Forward, @Jpf.SimpleAction, or @Jpf.ConditionalForward with navigateTo=currentPage or navigateTo=previousPage, then this method will always return null by default. To enable it in this situation, add the following method to the page flow:

protected boolean alwaysTrackPreviousPage()
{
    return true;
}


Returns:

a PreviousPageInfo with information about the most recent page shown to the user.

See Also:

getPreviousPageInfo(), getPreviousActionInfo(), getPreviousActionURI(), getPreviousFormBean(), getPreviousForwardPath(), getCurrentForwardPath()

getPreviousPageInfo

public final PreviousPageInfo getPreviousPageInfo()

Get information about the previous page (in this page flow) shown to the user. The previous page is the one shown before the most recent page.

Note: if the current page flow does not use a @Jpf.Forward, @Jpf.SimpleAction, or @Jpf.ConditionalForward with navigateTo=currentPage or navigateTo=previousPage, then this method will always return null by default. To enable it in this situation, add the following method to the page flow:

Returns:

a PreviousPageInfo with information about the previous page shown to the user.

See Also:

getCurrentPageInfo(), getPreviousActionInfo(), getPreviousActionURI(), getPreviousFormBean(), getPreviousForwardPath(), getCurrentForwardPath()

getPreviousActionInfo

public final PreviousActionInfo getPreviousActionInfo()

Get information about the most recent action run in this page flow.

Note: if the current page flow does not use a @Jpf.Forward, @Jpf.SimpleAction, or @Jpf.ConditionalForward with navigateTo=previousAction, then this method will always return null by default. To enable it in this situation, add the following method to the page flow:

protected boolean alwaysTrackPreviousAction()
{
    return true;
}


Returns:

a PreviousActionInfo with information about the most recent action run in this page flow.

See Also:

getPreviousPageInfo(), getCurrentPageInfo(), getPreviousActionURI(), getPreviousFormBean(), getPreviousForwardPath(), getCurrentForwardPath()

getDisplayName

public String getDisplayName()

Get the display name of this page flow.

Specified by:

getDisplayName in class PageFlowManagedObject

Returns:

the display name (the URI) of this page flow.

isPreviousActionInfoDisabled

public boolean isPreviousActionInfoDisabled()

isPreviousPageInfoDisabled

public boolean isPreviousPageInfoDisabled()

savePreviousPageInfo

public void savePreviousPageInfo(ActionForward forward,
                                 ActionForm form,
                                 ActionMapping mapping,
                                 HttpServletRequest request,
                                 ServletContext servletContext,
                                 boolean isSpecialForward)

Store information about recent pages displayed. This is a framework-invoked method that should not normally be called directly.

Overrides:

savePreviousPageInfo in class FlowController

valueUnbound

public void valueUnbound(HttpSessionBindingEvent event)

Callback when this object is removed from the user session. Causes FlowController.onDestroy() to be called. This is a framework-invoked method that should not normally be called indirectly.

Specified by:

valueUnbound in interface HttpSessionBindingListener

Overrides:

valueUnbound in class PageFlowManagedObject

exitNesting

public ActionForward exitNesting(HttpServletRequest request,
                                 HttpServletResponse response,
                                 ActionMapping mapping,
                                 ActionForm form)

onExitNesting

protected void onExitNesting()
                      throws Exception

Callback that is invoked when this controller instance is exiting nesting (through a return action). FlowController.getRequest(), FlowController.getResponse(), FlowController.getSession() may all be used during this method.

Throws:

Exception