Class NavigationHandler

java.lang.Object
jakarta.faces.application.NavigationHandler
Direct Known Subclasses:
ConfigurableNavigationHandler, NavigationHandlerWrapper
public abstract class NavigationHandler extends Object

A NavigationHandler is passed the outcome string returned by an application action invoked for this application, and will use this (along with related state information) to choose the view to be displayed next.

A default implementation of NavigationHandler must be provided by the Jakarta Faces implementation, which will be utilized unless setNavigationHandler() is called to establish a different one. An implementation of this class must be thread-safe. This default instance will compare the view identifier of the current view, the specified action binding, and the specified outcome against any navigation rules provided in faces-config.xml file(s). If a navigation case matches, the current view will be changed by a call to FacesContext.setViewRoot(). Note that a null outcome value will never match any navigation rule, so it can be used as an indicator that the current view should be redisplayed.

  • Constructor Details

    • NavigationHandler

      public NavigationHandler()

  • Method Details

    • handleNavigation

      public abstract void handleNavigation(FacesContext context, String fromAction, String outcome)

      Perform navigation processing based on the state information in the specified FacesContext, plus the outcome string returned by an executed application action.

      If the implementation class also extends ConfigurableNavigationHandler, the implementation must guarantee that the logic used in a call to ConfigurableNavigationHandler.getNavigationCase(FacesContext, String, String) is used in this method to determine the correct navigation.

      This method must set the render targets (used in partial rendering) to render all invoking PartialViewContext.setRenderAll(boolean)) if the view identifier has changed as the result of an application action (to take into account Ajax requests).

      Parameters:
      context - The FacesContext for the current request
      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)
      Throws:
      NullPointerException - if context is null

    • handleNavigation

      public void handleNavigation(FacesContext context, String fromAction, String outcome, String toFlowDocumentId)

      Overloaded variant of handleNavigation(jakarta.faces.context.FacesContext, java.lang.String, java.lang.String) that allows the caller to provide the defining document id for a flow to be entered by this navigation. For backward compatibility with decorated NavigationHandler implementations that conform to an earlier version of the specification, an implementation is provided that calls through to handleNavigation(jakarta.faces.context.FacesContext, java.lang.String, java.lang.String), ignoring the toFlowDocumentId parameter.

      Parameters:
      context - The FacesContext for the current request
      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)
      toFlowDocumentId - The defining document id of the flow into which this navigation will cause entry.
      Throws:
      NullPointerException - if context is null

    • getNavigationCase

      public NavigationCase getNavigationCase(FacesContext context, String fromAction, String outcome)

      Return the NavigationCase representing the navigation that would be taken had handleNavigation(FacesContext, String, String) been called with the same arguments or null if there is no such case.

      Historically this method was declared in ConfigurableNavigationHandler since 2.0. For backward compatibility with earlier implementations, a default implementation is provided which returns null.

      Parameters:
      context - The FacesContext for the current request
      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)
      Returns:
      the navigation case, or null.
      Throws:
      NullPointerException - if context is null
      Since:
      5.0

    • getNavigationCase

      public NavigationCase getNavigationCase(FacesContext context, String fromAction, String outcome, String toFlowDocumentId)

      Return the NavigationCase representing the navigation that would be taken had handleNavigation(FacesContext, String, String) been called with the same arguments or null if there is no such case. Implementations that comply the version of the specification in which this method was introduced must override this method. For compatibility with decorated implementations that comply with an earlier version of the specification, an implementation is provided that simply calls through to getNavigationCase(jakarta.faces.context.FacesContext, java.lang.String, java.lang.String), ignoring the toFlowDocumentId parameter.

      Historically this method was declared in ConfigurableNavigationHandler since 2.2.

      Parameters:
      context - The FacesContext for the current request
      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)
      toFlowDocumentId - The value of the toFlowDocumentId property for the navigation case (which may be null)
      Returns:
      the navigation case, or null.
      Throws:
      NullPointerException - if context is null
      Since:
      5.0

    • getNavigationCases

      public Map<String, Set<NavigationCase>> getNavigationCases()

      Return a Map<String, Set<NavigationCase>> where the keys are <from-view-id> values and the values are Set<NavigationCase> where each element in the Set is a NavigationCase that applies to that <from-view-id>. The implementation must support live modifications to this Map.

      Historically this method was declared in ConfigurableNavigationHandler since 2.0. For backward compatibility with earlier implementations, a default implementation is provided which returns an empty map.

      Returns:
      a map with navigation cases.
      Since:
      5.0

    • performNavigation

      public void performNavigation(String outcome)

      A convenience method to signal the Jakarta Faces implementation to perform navigation with the provided outcome. When the NavigationHandler is invoked, the current viewId is treated as the "from viewId" and the "from action" is null.

      Historically this method was declared in ConfigurableNavigationHandler since 2.0.

      Parameters:
      outcome - the provided outcome.
      Throws:
      IllegalStateException - if this method is called after this instance has been released
      Since:
      5.0

    • inspectFlow

      public void inspectFlow(FacesContext context, Flow flow)

      Called by the flow system to cause the flow to be inspected for navigation rules.

      Historically this method was declared in ConfigurableNavigationHandler since 2.2. For backward compatibility with earlier implementations, a default implementation is provided which does nothing.

      Parameters:
      context - the Faces context.
      flow - the flow.
      Since:
      5.0