public abstract class

DecoratingNavigationHandler

extends NavigationHandler
java.lang.Object
   ↳ NavigationHandler
     ↳ org.springframework.web.jsf.DecoratingNavigationHandler

Class Overview

Base class for JSF NavigationHandler implementations that want to be capable of decorating an original NavigationHandler.

Supports the standard JSF style of decoration (through a constructor argument) as well as an overloaded handleNavigation method with explicit NavigationHandler argument (passing in the original NavigationHandler). Subclasses are forced to implement this overloaded handleNavigation method. Standard JSF invocations will automatically delegate to the overloaded method, with the constructor-injected NavigationHandler as argument.

Summary

Protected Constructors
DecoratingNavigationHandler()
Create a DecoratingNavigationHandler without fixed original NavigationHandler.
DecoratingNavigationHandler(NavigationHandler originalNavigationHandler)
Create a DecoratingNavigationHandler with fixed original NavigationHandler.
Public Methods
final NavigationHandler getDecoratedNavigationHandler()
Return the fixed original NavigationHandler decorated by this handler, if any (that is, if passed in through the constructor).
final void handleNavigation(FacesContext facesContext, String fromAction, String outcome)
This implementation of the standard JSF handleNavigation method delegates to the overloaded variant, passing in constructor-injected NavigationHandler as argument.
abstract void handleNavigation(FacesContext facesContext, String fromAction, String outcome, NavigationHandler originalNavigationHandler)
Special handleNavigation variant with explicit NavigationHandler argument.
Protected Methods
final void callNextHandlerInChain(FacesContext facesContext, String fromAction, String outcome, NavigationHandler originalNavigationHandler)
Method to be called by subclasses when intending to delegate to the next handler in the NavigationHandler chain.
[Expand]
Inherited Methods
From class java.lang.Object

Protected Constructors

protected DecoratingNavigationHandler ()

Create a DecoratingNavigationHandler without fixed original NavigationHandler.

protected DecoratingNavigationHandler (NavigationHandler originalNavigationHandler)

Create a DecoratingNavigationHandler with fixed original NavigationHandler.

Parameters
originalNavigationHandler the original NavigationHandler to decorate

Public Methods

public final NavigationHandler getDecoratedNavigationHandler ()

Return the fixed original NavigationHandler decorated by this handler, if any (that is, if passed in through the constructor).

public final void handleNavigation (FacesContext facesContext, String fromAction, String outcome)

This implementation of the standard JSF handleNavigation method delegates to the overloaded variant, passing in constructor-injected NavigationHandler as argument.

See Also
  • #handleNavigation(javax.faces.context.FacesContext, String, String, javax.faces.application.NavigationHandler)

public abstract void handleNavigation (FacesContext facesContext, String fromAction, String outcome, NavigationHandler originalNavigationHandler)

Special handleNavigation variant with explicit NavigationHandler argument. Either called directly, by code with an explicit original handler, or called from the standard handleNavigation method, as plain JSF-defined NavigationHandler.

Implementations should invoke callNextHandlerInChain to delegate to the next handler in the chain. This will always call the most appropriate next handler (see callNextHandlerInChain javadoc). Alternatively, the decorated NavigationHandler or the passed-in original NavigationHandler can also be called directly; however, this is not as flexible in terms of reacting to potential positions in the chain.

Parameters
facesContext the current JSF context
fromAction the action binding expression that was evaluated to retrieve the specified outcome, or null if the outcome was acquired by some other means
outcome the logical outcome returned by a previous invoked application action (which may be null)
originalNavigationHandler the original NavigationHandler, or null if none

Protected Methods

protected final void callNextHandlerInChain (FacesContext facesContext, String fromAction, String outcome, NavigationHandler originalNavigationHandler)

Method to be called by subclasses when intending to delegate to the next handler in the NavigationHandler chain. Will always call the most appropriate next handler, either the decorated NavigationHandler passed in as constructor argument or the original NavigationHandler as passed into this method - according to the position of this instance in the chain.

Will call the decorated NavigationHandler specified as constructor argument, if any. In case of a DecoratingNavigationHandler as target, the original NavigationHandler as passed into this method will be passed on to the next element in the chain: This ensures propagation of the original handler that the last element in the handler chain might delegate back to. In case of a standard NavigationHandler as target, the original handler will simply not get passed on; no delegating back to the original is possible further down the chain in that scenario.

If no decorated NavigationHandler specified as constructor argument, this instance is the last element in the chain. Hence, this method will call the original NavigationHandler as passed into this method. If no original NavigantionHandler has been passed in (for example if this instance is the last element in a chain with standard NavigationHandlers as earlier elements), this method corresponds to a no-op.

Parameters
facesContext the current JSF context
fromAction the action binding expression that was evaluated to retrieve the specified outcome, or null if the outcome was acquired by some other means
outcome the logical outcome returned by a previous invoked application action (which may be null)
originalNavigationHandler the original NavigationHandler, or null if none