com.sun.faces.context.StateContext Maven / Gradle / Ivy
/*
* Copyright (c) 2012, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package com.sun.faces.context;
import static com.sun.faces.RIConstants.DYNAMIC_CHILD_COUNT;
import static com.sun.faces.RIConstants.DYNAMIC_COMPONENT;
import static com.sun.faces.util.ComponentStruct.ADD;
import static com.sun.faces.util.ComponentStruct.REMOVE;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.logging.Logger;
import javax.faces.FacesException;
import javax.faces.component.UIComponent;
import javax.faces.component.UIViewRoot;
import javax.faces.context.FacesContext;
import javax.faces.event.AbortProcessingException;
import javax.faces.event.PostAddToViewEvent;
import javax.faces.event.PreRemoveFromViewEvent;
import javax.faces.event.SystemEvent;
import javax.faces.event.SystemEventListener;
import com.sun.faces.RIConstants;
import com.sun.faces.application.ApplicationAssociate;
import com.sun.faces.application.ApplicationStateInfo;
import com.sun.faces.facelets.tag.jsf.ComponentSupport;
import com.sun.faces.util.ComponentStruct;
import com.sun.faces.util.FacesLogger;
import com.sun.faces.util.MostlySingletonSet;
/**
* Context for dealing with partial state saving mechanics.
*/
public class StateContext {
private static final String KEY = StateContext.class.getName() + "_KEY";
private boolean partial;
private boolean partialLocked;
private boolean trackMods = true;
private AddRemoveListener modListener;
private ApplicationStateInfo stateInfo;
private WeakReference viewRootRef = new WeakReference<>(null);
private static final Logger LOGGER = FacesLogger.CONTEXT.getLogger();
// ------------------------------------------------------------ Constructors
private StateContext(ApplicationStateInfo stateInfo) {
this.stateInfo = stateInfo;
}
// ---------------------------------------------------------- Public Methods
/**
* Release the state context.
*
* @param facesContext the Faces context.
*/
public static void release(FacesContext facesContext) {
StateContext stateContext = (StateContext) facesContext.getAttributes().get(KEY);
UIViewRoot viewRoot = facesContext.getViewRoot();
if (viewRoot != null && stateContext.modListener != null) {
viewRoot.unsubscribeFromViewEvent(PostAddToViewEvent.class, stateContext.modListener);
viewRoot.unsubscribeFromViewEvent(PreRemoveFromViewEvent.class, stateContext.modListener);
}
facesContext.getAttributes().remove(KEY);
}
/**
* @param ctx the FacesContext
for the current request
* @return StateContext
for this request
*/
public static StateContext getStateContext(FacesContext ctx) {
StateContext stateCtx = (StateContext) ctx.getAttributes().get(KEY);
if (stateCtx == null) {
ApplicationAssociate associate = ApplicationAssociate.getCurrentInstance();
ApplicationStateInfo info = associate.getApplicationStateInfo();
stateCtx = new StateContext(info);
ctx.getAttributes().put(KEY, stateCtx);
}
return stateCtx;
}
/**
* @param ctx FacesContext.
* @param viewId the view ID to check or null if viewId is unknown.
* @return true
if partial state saving should be used for the
* specified view ID, otherwise false
*/
public boolean isPartialStateSaving(FacesContext ctx, String viewId) {
// track UIViewRoot changes
UIViewRoot root = ctx.getViewRoot();
UIViewRoot refRoot = viewRootRef.get();
if (root != refRoot) {
// set weak reference to current viewRoot
this.viewRootRef = new WeakReference<>(root);
// On first call in restore phase, viewRoot is null, so we treat the first
// change to not null not as a changing viewRoot.
if (refRoot != null) {
// view root changed in request processing - force usage of a
// new AddRemoveListener instance for the new viewId ...
modListener = null;
// ... and also force check for partial state saving for the new viewId
partialLocked = false;
}
}
if (!partialLocked) {
if (viewId == null) {
if (root != null) {
viewId = root.getViewId();
} else {
// View root has not yet been initialized. Check to see whether
// the target view id has been stashed away for us.
viewId = (String)ctx.getAttributes().get(RIConstants.VIEWID_KEY_NAME);
}
}
partial = stateInfo.usePartialStateSaving(viewId);
partialLocked = true;
}
return partial;
}
/**
* @return true
if view modifications outside of the initial
* construction of the view are being tracked.
*/
public boolean trackViewModifications() {
return trackMods;
}
/**
* Installs a SystemEventListener
on the UIViewRoot
* to track components added to or removed from the view.
*/
public void startTrackViewModifications(FacesContext ctx, UIViewRoot root) {
if (modListener == null) {
if (root != null) {
modListener = createAddRemoveListener(ctx, root);
root.subscribeToViewEvent(PostAddToViewEvent.class, modListener);
root.subscribeToViewEvent(PreRemoveFromViewEvent.class, modListener);
} else {
LOGGER.warning("Unable to attach AddRemoveListener to UIViewRoot because it is null");
}
}
setTrackViewModifications(true);
}
/**
* Toggles the current modification tracking status.
*
* @param trackMods if true
and the listener installed by
* {@link #startTrackViewModifications(javax.faces.context.FacesContext, javax.faces.component.UIViewRoot)
* is present, then view modifications will be tracked. If
* false
, then modification events will be ignored.
*/
public void setTrackViewModifications(boolean trackMods) {
this.trackMods = trackMods;
}
/**
* @param c the UIComponent to check
* @return true
if the component was added after the initial
* view construction
*/
public boolean componentAddedDynamically(UIComponent c) {
return c.getAttributes().containsKey(DYNAMIC_COMPONENT);
}
public int getIndexOfDynamicallyAddedChildInParent(UIComponent c) {
int result = -1;
Map attrs = c.getAttributes();
if (attrs.containsKey(DYNAMIC_COMPONENT)) {
result = (Integer) attrs.get(DYNAMIC_COMPONENT);
}
return result;
}
public boolean hasOneOrMoreDynamicChild(UIComponent parent) {
return parent.getAttributes().containsKey(DYNAMIC_CHILD_COUNT);
}
private int incrementDynamicChildCount(FacesContext context, UIComponent parent) {
int result;
Map attrs = parent.getAttributes();
Integer cur = (Integer) attrs.get(DYNAMIC_CHILD_COUNT);
if (null != cur) {
result = cur++;
} else {
result = 1;
}
attrs.put(DYNAMIC_CHILD_COUNT, (Integer) result);
context.getViewRoot().getAttributes().put(RIConstants.TREE_HAS_DYNAMIC_COMPONENTS, Boolean.TRUE);
return result;
}
private int decrementDynamicChildCount(FacesContext context, UIComponent parent) {
int result = 0;
Map attrs = parent.getAttributes();
Integer cur = (Integer) attrs.get(DYNAMIC_CHILD_COUNT);
if (null != cur) {
result = (0 < cur) ? cur-- : 0;
}
if (0 == result && null != cur){
attrs.remove(DYNAMIC_CHILD_COUNT);
}
context.getViewRoot().getAttributes().put(RIConstants.TREE_HAS_DYNAMIC_COMPONENTS, Boolean.TRUE);
return result;
}
/**
* Get the dynamic list (of adds and removes).
*/
public List getDynamicActions() {
return ((modListener != null) ? modListener.getDynamicActions() : null);
}
/**
* Get the hash map of dynamic components.
*
* @return the hash map of dynamic components.
*/
public HashMap getDynamicComponents() {
return ((modListener != null) ? modListener.getDynamicComponents() : null);
}
// ---------------------------------------------------------- Nested Classes
private AddRemoveListener createAddRemoveListener(FacesContext context, UIViewRoot root) {
return isPartialStateSaving(context, root.getViewId()) ?
new DynamicAddRemoveListener(context) :
new StatelessAddRemoveListener(context);
}
abstract private class AddRemoveListener implements SystemEventListener {
/**
* Stores the state context we work for,
*/
private StateContext stateCtx;
/**
* Constructor.
*
* @param context the Faces context.
*/
protected AddRemoveListener(FacesContext context) {
stateCtx = StateContext.getStateContext(context);
}
/**
* Get the list of adds/removes.
*
* @return the list of adds/removes.
*/
abstract public List getDynamicActions();
/**
* Get the hash map of dynamic components.
*
* @return the hash map of dynamic components.
*/
abstract public HashMap getDynamicComponents();
/**
* Process the add/remove event.
*
* @param event the add/remove event.
* @throws AbortProcessingException when processing should be aborted.
*/
@Override
public void processEvent(SystemEvent event)
throws AbortProcessingException {
FacesContext ctx = FacesContext.getCurrentInstance();
if (event instanceof PreRemoveFromViewEvent) {
if (stateCtx.trackViewModifications()) {
handleRemove(ctx, ((PreRemoveFromViewEvent) event).getComponent());
ctx.getViewRoot().getAttributes().put(RIConstants.TREE_HAS_DYNAMIC_COMPONENTS, Boolean.TRUE);
}
} else {
if (stateCtx.trackViewModifications()) {
handleAdd(ctx, ((PostAddToViewEvent) event).getComponent());
ctx.getViewRoot().getAttributes().put(RIConstants.TREE_HAS_DYNAMIC_COMPONENTS, Boolean.TRUE);
}
}
}
/**
* Are we listening for these particular changes.
*
*
* Note we are only interested in UIComponent adds/removes that are
* not the UIViewRoot itself.
*
*
* @param source the source object we might be listening for.
* @return true if the source is OK, false otherwise.
*/
@Override
public boolean isListenerForSource(Object source) {
return (source instanceof UIComponent && !(source instanceof UIViewRoot));
}
/**
* Handle the remove.
*
* @param context the Faces context.
* @param component the UI component to add to the list as a REMOVE.
*/
abstract protected void handleRemove(FacesContext context, UIComponent component);
/**
* Handle the add.
*
* @param context the Faces context.
* @param component the UI component to add to the list as an ADD.
*/
abstract protected void handleAdd(FacesContext context, UIComponent component);
}
public class NoopAddRemoveListener extends AddRemoveListener {
// This is silly. We should be able to use Colletions.emptyMap(),
// but cannot as StateContext.getDynamicComponents() API returns a
// HashMap instead of a Map.
private HashMap emptyComponentsMap = new HashMap();
public NoopAddRemoveListener(FacesContext context) {
super(context);
}
@Override
public List getDynamicActions() {
return Collections.emptyList();
}
@Override
public HashMap getDynamicComponents() {
return emptyComponentsMap;
}
@Override
protected void handleRemove(FacesContext context, UIComponent component) {
}
@Override
protected void handleAdd(FacesContext context, UIComponent component) {
}
}
/**
* An AddRemoveListener that implements the new dynamic component
* strategy where no state is managed by the listener itself. Instead,
* we use expando attributes on the dynamic components (and their parents)
* to track/preserve the dynamic nature of these components.
*/
public class StatelessAddRemoveListener extends NoopAddRemoveListener {
public StatelessAddRemoveListener(FacesContext context) {
super(context);
}
private boolean thisEventCorrespondsToSubtreeRootRemove(FacesContext context, UIComponent c) {
boolean result = false;
if (null != c) {
c = c.getParent();
if (null != c) {
result = c.isInView();
}
}
return result;
}
private boolean thisEventCorrespondsToSubtreeRootAdd(FacesContext context, UIComponent c) {
boolean result = false;
Map