org.apache.myfaces.view.facelets
Class DefaultFaceletsStateManagementStrategy

java.lang.Object
  extended by javax.faces.view.StateManagementStrategy
      extended by org.apache.myfaces.view.facelets.DefaultFaceletsStateManagementStrategy

public class DefaultFaceletsStateManagementStrategy
extends StateManagementStrategy

This class implements partial state saving feature when facelets is used to render pages. (Theorically it could be applied on jsp case too, but all considerations below should be true before apply it). The following considerations apply for this class: 1. This StateManagementStrategy should only be active if javax.faces.PARTIAL_STATE_SAVING config param is active(true). See javadoc on StateManager for details. 2. A map using component clientId as keys are used to hold the state. 3. Each component has a valid id after ViewDeclarationLanguage.buildView(). This implies that somewhere, every TagHandler that create an UIComponent instance should call setId and assign it. 4. Every TagHandler that create an UIComponent instance should call markInitialState after the component is populated. Otherwise, full state is always saved. 5. A SystemEventListener is used to keep track for added and removed components, listen PostAddToViewEvent and PreRemoveFromViewEvent event triggered by UIComponent.setParent() method. 6. It is not possible to use javax.faces.component.visit API to traverse the component tree during save/restore, because UIData.visitTree traverse all rows and we only need to restore state per component (not per row). 7. It is necessary to preserve the order of the children added/removed between requests. 8. Added and removed components could be seen as subtrees. This imply that we need to save the structure of the added components subtree and remove one component could be remove all its children and facets from view inclusive. 9. It is necessary to save and restore the list of added/removed components between several requests. 10.All components ids removed in any moment of time must be preserved. 11.Each component must be restored only once. 11.The order is important for ids added when it is traversed the tree, otherwise the algorithm could change the order in which components will be restored.

Since:
2.0
Version:
$Revision: 793245 $ $Date: 2009-07-11 18:50:53 -0500 (Sat, 11 Jul 2009) $
Author:
Leonardo Uribe (latest modification by $Author: lu4242 $)

Nested Class Summary
static class DefaultFaceletsStateManagementStrategy.PostAddPreRemoveFromViewListener
           
static class DefaultFaceletsStateManagementStrategy.TreeStructComponent
           
 
Field Summary
static String CLIENTIDS_ADDED
           
static String CLIENTIDS_REMOVED
           
static String COMPONENT_ADDED_AFTER_BUILD_VIEW
          Key used on component attribute map to indicate if a component was added after build view, so itself and all descendants should not use partial state saving.
 
Constructor Summary
DefaultFaceletsStateManagementStrategy()
           
 
Method Summary
protected  void ensureClearInitialState(UIComponent c)
           
 UIViewRoot restoreView(FacesContext context, String viewId, String renderKitId)
           
 Object saveView(FacesContext context)
           
 void suscribeListeners(UIViewRoot uiViewRoot)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

CLIENTIDS_ADDED

public static final String CLIENTIDS_ADDED
See Also:
Constant Field Values

CLIENTIDS_REMOVED

public static final String CLIENTIDS_REMOVED
See Also:
Constant Field Values

COMPONENT_ADDED_AFTER_BUILD_VIEW

public static final String COMPONENT_ADDED_AFTER_BUILD_VIEW
Key used on component attribute map to indicate if a component was added after build view, so itself and all descendants should not use partial state saving. There are two possible values: Key not present: The component uses pss. ComponentState.ADD: The component was added to the view after build view. ComponentState.REMOVE_ADD: The component was removed/added to the view. Itself and all descendants should be saved and restored, but we have to unregister/register from CLIENTIDS_ADDED and CLIENTIDS_REMOVED lists. See ComponentSupport.markComponentToRestoreFully for details. ComponentState.ADDED: The component has been added or removed/added, but it has been already processed.

See Also:
Constant Field Values
Constructor Detail

DefaultFaceletsStateManagementStrategy

public DefaultFaceletsStateManagementStrategy()
Method Detail

restoreView

public UIViewRoot restoreView(FacesContext context,
                              String viewId,
                              String renderKitId)
Specified by:
restoreView in class StateManagementStrategy

saveView

public Object saveView(FacesContext context)
Specified by:
saveView in class StateManagementStrategy

ensureClearInitialState

protected void ensureClearInitialState(UIComponent c)

suscribeListeners

public void suscribeListeners(UIViewRoot uiViewRoot)


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