Convenience struct for encapsulating tree structure and component state. This is necessary to allow the API to be flexible enough to work in JSP and non-JSP environments.

The ServletContext init parameter consulted by the StateManager to tell where the state should be saved. Valid values are given as the values of the constants: #STATE_SAVING_METHOD_CLIENT or #STATE_SAVING_METHOD_SERVER .

If this parameter is not specified, the default value is the value of the constant #STATE_SAVING_METHOD_CLIENT .

Constant value for the initialization parameter named by the STATE_SAVING_METHOD_PARAM_NAME that indicates state saving should take place on the client.

Constant value for the initialization parameter named by the STATE_SAVING_METHOD_PARAM_NAME that indicates state saving should take place on the server.

 protected Object getComponentStateToSave(FacesContext context) 
{
        return null;
}

Convenience method, which must be called by saveSerializedView(), to construct and return a Serializable object that represents the state of all component properties, attributes, and attached objects, for the entire component tree (including children and facets) of this view.

Components may opt-out of being included in the component state by setting their transient property to true. This must cause the component itself, as well as all of that component's children and facets, to be omitted from the saved component state information.

 protected Object getTreeStructureToSave(FacesContext context) 
{
        return null;
}

Convenience method, which must be called by saveSerializedView(), to construct and return a Serializable object that represents the structure of the entire component tree (including children and facets) of this view.

Components may opt-out of being included in the tree structure by setting their transient property to true. This must cause the component itself, as well as all of that component's children and facets, to be omitted from the saved tree structure information.

 public boolean isSavingStateInClient(FacesContext context) 
{
                                                                                                              
        if (null != savingStateInClient) {
            return savingStateInClient.booleanValue();
        }
        savingStateInClient = Boolean.FALSE;
        String saveStateParam = context.getExternalContext().
              getInitParameter(STATE_SAVING_METHOD_PARAM_NAME);
        if (saveStateParam != null &&
            saveStateParam.equalsIgnoreCase(STATE_SAVING_METHOD_CLIENT)) {
            savingStateInClient = Boolean.TRUE;
        }
        return savingStateInClient.booleanValue();
}

 protected  void restoreComponentState(FacesContext context,
    UIViewRoot viewRoot,
    String renderKitId) 
{

}

Convenience method, which must be called by restoreView(), to restore the attributes, properties, and attached objects of all components in the restored component tree.

 protected UIViewRoot restoreTreeStructure(FacesContext context,
    String viewId,
    String renderKitId) 
{
        return null;
}

Convenience method, which must be called by restoreView(), to construct and return a UIViewRoot instance (populated with children and facets) representing the tree structure of the component tree being restored. If no saved state information is available, return null instead.

 abstract public UIViewRoot restoreView(FacesContext context,
    String viewId,
    String renderKitId)
Restore the tree structure and the component state of the view
for the specified viewId, in an implementation dependent
manner, and return the restored UIViewRoot . If there is no
saved state information available for this viewId,
return null instead.

This method must consult the context initialization parameter
named by the symbolic constant
StateManager.STATE_SAVING_METHOD_PARAMETER_NAME
to determine whether state should be saved on the client or the
server. If not present, client side state saving is assumed.

If the init parameter indicates that client side state
saving should be used, this method must call the
getTreeStructureToRestore() and (if the previous method
call returned a non-null value) getComponentStateToRestore()
methods of the ResponseStateManager  instance provided by the
RenderKit  responsible for this view.

 public StateManager.SerializedView saveSerializedView(FacesContext context) 
{
    // ---------------------------------------------------- State Saving Methods
        return null;
}

Return the tree structure and component state information for the view contained in the specified FacesContext instance as an object of type StateManager.SerializedView. If there is no state information to be saved, return null instead.

Components may opt out of being included in the serialized view by setting their transient property to true. This must cause the component itself, as well as all of that component's children and facets, to be omitted from the saved tree structure and component state information.

This method must also enforce the rule that, for components with non-null ids, all components that are descendants of the same nearest NamingContainer must have unique identifiers.

 public Object saveView(FacesContext context) 
{
        SerializedView view = saveSerializedView(context);
        Object stateArray[] = {view.getStructure(),
                               view.getState()};
        return stateArray;
}

Return an opaque Object containing sufficient information for this same instance to restore the state of the current UIViewRoot on a subsequent request. The returned object must implement java.io.Serializable. If there is no state information to be saved, return null instead.

Components may opt out of being included in the serialized view by setting their transient property to true. This must cause the component itself, as well as all of that component's children and facets, to be omitted from the saved tree structure and component state information.

This method must also enforce the rule that, for components with non-null ids, all components that are descendants of the same nearest NamingContainer must have unique identifiers.

For backwards compatability with existing StateManager implementations, the default implementation of this method calls #saveSerializedView and creates and returns a two element Object array with element zero containing the structure property and element one containing the state property of the SerializedView.

 public  void writeState(FacesContext context,
    Object state) throws IOException 
{
        if (null != state && state.getClass().isArray() &&
            state.getClass().getComponentType().equals(Object.class)) {
            Object stateArray[] = (Object[]) state;
            if (2 == stateArray.length) {
                SerializedView view = new SerializedView(stateArray[0],
                                                         stateArray[1]);
                writeState(context, view);
            }
        }
}

Save the state represented in the specified state Object instance, in an implementation dependent manner.

This method will typically simply delegate the actual writing to the writeState() method of the ResponseStateManager instance provided by the RenderKit being used to render this view. This method assumes that the caller has positioned the ResponseWriter at the correct position for the saved state to be written.

For backwards compatability with existing StateManager implementations, the default implementation of this method checks if the argument is an instance of Object [] of length greater than or equal to two. If so, it creates a SerializedView instance with the tree structure coming from element zero and the component state coming from element one and calls through to #writeState(javax.faces.context.FacesContext,javax.faces.application.StateManager.SerializedView) . If not, does nothing.

 public  void writeState(FacesContext context,
    StateManager.SerializedView state) throws IOException 
{

}

Save the state represented in the specified SerializedView isntance, in an implementation dependent manner.

This method must consult the context initialization parameter named by the symbolic constant StateManager.STATE_SAVING_METHOD_PARAMETER_NAME to determine whether state should be saved on the client or the server. If not present, client side state saving is assumed.

If the init parameter indicates that client side state saving should be used, this method must delegate the actual writing to the writeState() method of the ResponseStateManager instance provided by the RenderKit being used to render this view. This method assumes that the caller has positioned the ResponseWriter at the correct position for the saved state to be written.