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Jakarta Faces defines an MVC framework for building user interfaces for web applications,
including UI components, state management, event handing, input validation, page navigation, and
support for internationalization and accessibility.
/*
* Copyright (c) 1997, 2020 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.component.visit;
import java.util.AbstractCollection;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import jakarta.faces.component.NamingContainer;
import jakarta.faces.component.UIComponent;
import jakarta.faces.component.UINamingContainer;
import jakarta.faces.component.visit.VisitCallback;
import jakarta.faces.component.visit.VisitContext;
import jakarta.faces.component.visit.VisitHint;
import jakarta.faces.component.visit.VisitResult;
import jakarta.faces.context.FacesContext;
/**
*
*
* A VisitContext implementation that is used when performing a partial component tree visit.
*
*
* RELEASE_PENDING
*
* @since 2.0
*/
public class PartialVisitContext extends VisitContext {
/**
* Creates a PartialVisitorContext instance.
*
* @param facesContext the FacesContext for the current request
* @param clientIds the client ids of the components to visit
* @throws NullPointerException if {@code facesContext} is {@code null}
*/
public PartialVisitContext(FacesContext facesContext, Collection clientIds) {
this(facesContext, clientIds, null);
}
/**
* Creates a PartialVisitorContext instance with the specified hints.
*
* @param facesContext the FacesContext for the current request
* @param clientIds the client ids of the components to visit
* @param hints a the VisitHints for this visit
* @throws NullPointerException if {@code facesContext} is {@code null}
*/
public PartialVisitContext(FacesContext facesContext, Collection clientIds, Set hints) {
if (facesContext == null) {
throw new NullPointerException();
}
this.facesContext = facesContext;
// Initialize our various collections
initializeCollections(clientIds);
// Copy and store hints - ensure unmodifiable and non-empty
EnumSet hintsEnumSet = hints == null || hints.isEmpty() ? EnumSet.noneOf(VisitHint.class) : EnumSet.copyOf(hints);
this.hints = Collections.unmodifiableSet(hintsEnumSet);
}
/**
* @see VisitContext#getFacesContext VisitContext.getFacesContext()
*/
@Override
public FacesContext getFacesContext() {
return facesContext;
}
/**
* @see VisitContext#getHints VisitContext.getHints
*/
@Override
public Set getHints() {
return hints;
}
/**
* @see VisitContext#getIdsToVisit VisitContext.getIdsToVisit()
*/
@Override
public Collection getIdsToVisit() {
// We just return our clientIds collection. This is
// the modifiable (but proxied) collection of all of
// the client ids to visit.
return clientIds;
}
public Collection getUnvisitedClientIds() {
return unvisitedClientIds;
}
/**
* @see VisitContext#getSubtreeIdsToVisit VisitContext.getSubtreeIdsToVisit()
*/
@Override
public Collection getSubtreeIdsToVisit(UIComponent component) {
// Make sure component is a NamingContainer
if (!(component instanceof NamingContainer)) {
throw new IllegalArgumentException("Component is not a NamingContainer: " + component);
}
String clientId = component.getClientId();
Collection ids = subtreeClientIds.get(clientId);
if (ids == null) {
return Collections.emptyList();
}
return Collections.unmodifiableCollection(ids);
}
/**
* @see VisitContext#invokeVisitCallback VisitContext.invokeVisitCallback()
*/
@Override
public VisitResult invokeVisitCallback(UIComponent component, VisitCallback callback) {
// First sure that we should visit this component - ie.
// that this component is represented in our id set.
String clientId = getVisitId(component);
if (clientId == null) {
// Not visiting this component, but allow visit to
// continue into this subtree in case we've got
// visit targets there.
return VisitResult.ACCEPT;
}
// If we made it this far, the component matches one of
// client ids, so perform the visit.
VisitResult result = callback.visit(this, component);
// Remove the component from our "unvisited" collection
unvisitedClientIds.remove(clientId);
// If the unvisited collection is now empty, we are done.
// Return VisitResult.COMPLETE to terminate the visit.
if (unvisitedClientIds.isEmpty()) {
return VisitResult.COMPLETE;
}
// Otherwise, just return the callback's result
return result;
}
// Called by CollectionProxy to notify PartialVisitContext that
// an new id has been added.
private void idAdded(String clientId) {
// An id to visit has been added, update our other
// collections to reflect this.
// Update the ids collection
ids.add(getIdFromClientId(clientId));
// Update the unvisited ids collection
unvisitedClientIds.add(clientId);
// Update the subtree ids collection
addSubtreeClientId(clientId);
}
// Called by CollectionProxy to notify PartialVisitContext that
// an id has been removed
private void idRemoved(String clientId) {
// An id to visit has been removed, update our other
// collections to reflect this. Note that we don't
// update the ids collection, since we ids (non-client ids)
// may not be unique.
// Update the unvisited ids collection
unvisitedClientIds.remove(clientId);
// Update the subtree ids collection
removeSubtreeClientId(clientId);
}
// Called to initialize our various collections.
private void initializeCollections(Collection clientIds) {
// We maintain 4 collections:
//
// 1. clientIds: contains all of the client ids to visit
// 2. ids: contains just ids (not client ids) to visit.
// We use this to optimize our check to see whether a
// particular component is in the visit set (ie. to
// avoid having to compute the client id).
// 3. subtreeClientIds: contains client ids to visit broken
// out by naming container subtree. (Needed by
// getSubtreeIdsToVisit()).
// 4. unvisitedClientIds: contains the client ids to visit that
// have not yet been visited.
//
// We populate these now.
//
// Note that we use default HashSet/Map initial capacities, though
// perhaps we could pick more intelligent defaults.
// Initialize unvisitedClientIds collection
unvisitedClientIds = new HashSet<>();
// Initialize ids collection
ids = new HashSet<>();
// Initialize subtreeClientIds collection
subtreeClientIds = new HashMap<>();
// Initialize the clientIds collection. Note that we proxy
// this collection so that we can trap adds/removes and sync
// up all of the other collections.
this.clientIds = new CollectionProxy<>(new HashSet<>());
// Finally, populate the clientIds collection. This has the
// side effect of populating all of the other collections.
this.clientIds.addAll(clientIds);
}
// Tests whether the specified component should be visited.
// If so, returns its client id. If not, returns null.
private String getVisitId(UIComponent component) {
// We first check to see whether the component's id
// is in our id collection. We do this before checking
// for the full client id because getting the full client id
// is more expensive than just getting the local id.
String id = component.getId();
if (id != null && !ids.contains(id)) {
return null;
}
// The id was a match - now check the client id.
// note that client id should never be null (should be
// generated even if id is null, so asserting this.)
String clientId = component.getClientId();
assert clientId != null;
return clientIds.contains(clientId) ? clientId : null;
}
// Converts a client id into a plain old id by ripping
// out the trailing id segment.
private String getIdFromClientId(String clientId) {
FacesContext facesContext = getFacesContext();
char separator = UINamingContainer.getSeparatorChar(facesContext);
int lastIndex = clientId.lastIndexOf(separator);
String id = null;
if (lastIndex < 0) {
id = clientId;
} else if (lastIndex < clientId.length() - 1) {
id = clientId.substring(lastIndex + 1);
}
return id;
}
// Given a single client id, populate the subtree map with all possible
// subtree client ids
private void addSubtreeClientId(String clientId) {
FacesContext facesContext = getFacesContext();
char separator = UINamingContainer.getSeparatorChar(facesContext);
// Loop over the client id and find the substring corresponding to
// each ancestor NamingContainer client id. For each ancestor
// NamingContainer, add an entry into the map for the full client
// id.
int length = clientId.length();
for (int i = 0; i < length; i++) {
if (clientId.charAt(i) == separator) {
// We found an ancestor NamingContainer client id - add
// an entry to the map.
String namingContainerClientId = clientId.substring(0, i);
// Check to see whether we've already ids under this
// NamingContainer client id. If not, create the
// Collection for this NamingContainer client id and
// stash it away in our map
Collection c = subtreeClientIds.computeIfAbsent(namingContainerClientId, k -> new ArrayList<>());
// Stash away the client id
c.add(clientId);
}
}
}
// Given a single client id, remove any entries corresponding
// entries from our subtree collections
private void removeSubtreeClientId(String clientId) {
// Loop through each entry in the map and check to see whether
// the client id to remove should be contained in the corresponding
// collection - ie. whether the key (the NamingContainer client id)
// is present at the start of the client id to remove.
for (String key : subtreeClientIds.keySet()) {
if (clientId.startsWith(key)) {
// If the clientId starts with the key, we should
// have an entry for this clientId in the corresponding
// collection. Remove it.
Collection ids = subtreeClientIds.get(key);
ids.remove(clientId);
}
}
}
// Little proxy collection implementation. We proxy the id
// collection so that we can detect modifications and update
// our internal state when ids to visit are added or removed.
private class CollectionProxy extends AbstractCollection {
private CollectionProxy(Collection wrapped) {
this.wrapped = wrapped;
}
@Override
public int size() {
return wrapped.size();
}
@Override
public Iterator iterator() {
return new IteratorProxy<>(wrapped.iterator());
}
@Override
public boolean add(E o) {
boolean added = wrapped.add(o);
if (added) {
idAdded(o);
}
return added;
}
private final Collection wrapped;
}
// Little proxy iterator implementation used by CollectionProxy
// so that we can catch removes.
private class IteratorProxy implements Iterator {
private IteratorProxy(Iterator wrapped) {
this.wrapped = wrapped;
}
@Override
public boolean hasNext() {
return wrapped.hasNext();
}
@Override
public E next() {
current = wrapped.next();
return current;
}
@Override
public void remove() {
if (current != null) {
idRemoved(current);
}
wrapped.remove();
}
private final Iterator wrapped;
private E current = null;
}
// The client ids to visit
private Collection clientIds;
// The ids to visit
private Collection ids;
// The client ids that have yet to be visited
private Collection unvisitedClientIds;
// This map contains the information needed by getSubtreeIdsToVisit().
// The keys in this map are NamingContainer client ids. The values
// are collections containing all of the client ids to visit within
// corresponding naming container.
private Map> subtreeClientIds;
// The FacesContext for this request
private final FacesContext facesContext;
// Our visit hints
private final Set hints;
}
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