org.springframework.web.jsf

Class DecoratingNavigationHandler



  • public abstract class DecoratingNavigationHandler
    extends NavigationHandler
    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.

    Since:
    1.2.7
    Author:
    Juergen Hoeller
    See Also:
    handleNavigation(javax.faces.context.FacesContext, String, String, NavigationHandler), DelegatingNavigationHandlerProxy
    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method and Description
      protected void callNextHandlerInChain(FacesContext facesContext, java.lang.String fromAction, java.lang.String outcome, NavigationHandler originalNavigationHandler)
      Method to be called by subclasses when intending to delegate to the next handler in the NavigationHandler chain.
      NavigationHandler getDecoratedNavigationHandler()
      Return the fixed original NavigationHandler decorated by this handler, if any (that is, if passed in through the constructor).
      void handleNavigation(FacesContext facesContext, java.lang.String fromAction, java.lang.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, java.lang.String fromAction, java.lang.String outcome, NavigationHandler originalNavigationHandler)
      Special handleNavigation variant with explicit NavigationHandler argument.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • DecoratingNavigationHandler

        protected DecoratingNavigationHandler()
        Create a DecoratingNavigationHandler without fixed original NavigationHandler.
      • DecoratingNavigationHandler

        protected DecoratingNavigationHandler(NavigationHandler originalNavigationHandler)
        Create a DecoratingNavigationHandler with fixed original NavigationHandler.
        Parameters:
        originalNavigationHandler - the original NavigationHandler to decorate
    • Method Detail

      • getDecoratedNavigationHandler

        @Nullable
        public final NavigationHandler getDecoratedNavigationHandler()
        Return the fixed original NavigationHandler decorated by this handler, if any (that is, if passed in through the constructor).
      • handleNavigation

        public abstract void handleNavigation(FacesContext facesContext,
                                              @Nullable
                                              java.lang.String fromAction,
                                              @Nullable
                                              java.lang.String outcome,
                                              @Nullable
                                              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
        See Also:
        callNextHandlerInChain(javax.faces.context.FacesContext, java.lang.String, java.lang.String, javax.faces.application.NavigationHandler)
      • callNextHandlerInChain

        protected final void callNextHandlerInChain(FacesContext facesContext,
                                                    @Nullable
                                                    java.lang.String fromAction,
                                                    @Nullable
                                                    java.lang.String outcome,
                                                    @Nullable
                                                    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 NavigationHandler 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