com.sun.faces.facelets.el.ContextualCompositeValueExpression Maven / Gradle / Ivy
Show all versions of jsf-impl Show documentation
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*
*
* This file incorporates work covered by the following copyright and
* permission notice:
*
* Copyright 2005-2007 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.sun.faces.facelets.el;
import com.sun.faces.component.CompositeComponentStackManager;
import javax.el.ValueExpression;
import javax.el.ELContext;
import javax.faces.view.Location;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
/**
*
* This specialized ValueExpression
enables the evaluation of
* composite component expressions. Instances of this expression will be
* created when {@link com.sun.faces.facelets.tag.TagAttributeImpl#getValueExpression(javax.faces.view.facelets.FaceletContext, Class)}
* is invoked and the expression represents a composite component expression (i.e. #{cc.[properties]}).
*
*
*
* It's important to note that these ValueExpression
s are context
* sensitive in that they leverage the location in which they were referenced
* in order to push the proper composite component to the evaluation context
* prior to evaluating the expression itself.
*
*
* Here's an example:
*
*
* Using Page test.xhtml
* ---------------------------------
* <ez:comp1 greeting="Hello!" />
*
*
* comp1.xhtml
* ---------------------------------
* <composite:interface>
* <composite:attribute name="greeting" type="java.lang.String" required="true" />
* </composite:interface>
* <composite:implementation>
* <ez:nesting>
* <h:outputText value="#{cc.attrs.greetings}" />
* </ez:nesting>
* </composite:implementation>
*
* nesting.xhtml
* ---------------------------------
* <composite:interface />
* <composite:implementation>
* <composite:insertChildren>
* </composite:implementation>
*
*
*
* In the above example, there will be two composite components available to
* the runtime: ez:comp1
and ez:nesting
.
*
*
*
* When <h:outputText value="#{cc.attrs.greeting}" />, prior to attempting
* to evaluate the expression, the {@link Location} object will be used to
* find the composite component that 'owns' the template in which
* the expression was defined in by comparing the path of the Location with the
* name and library of the {@link javax.faces.application.Resource} instance associated
* with each composite component. If a matching composite component is found,
* it will be made available to the EL by calling {@link CompositeComponentStackManager#push(javax.faces.component.UIComponent)}.
*
*/
public final class ContextualCompositeValueExpression extends ValueExpression {
private static final long serialVersionUID = -2637560875633456679L;
private ValueExpression originalVE;
private Location location;
// ---------------------------------------------------- Constructors
/* For serialization purposes */
public ContextualCompositeValueExpression() { }
public ContextualCompositeValueExpression(Location location,
ValueExpression originalVE) {
this.originalVE = originalVE;
this.location = location;
}
// ------------------------------------ Methods from ValueExpression
public Object getValue(ELContext elContext) {
FacesContext ctx = (FacesContext) elContext.getContext(FacesContext.class);
boolean pushed = pushCompositeComponent(ctx);
try {
return originalVE.getValue(elContext);
} finally {
if (pushed) {
popCompositeComponent(ctx);
}
}
}
public void setValue(ELContext elContext, Object o) {
FacesContext ctx = (FacesContext) elContext.getContext(FacesContext.class);
boolean pushed = pushCompositeComponent(ctx);
try {
originalVE.setValue(elContext, o);
} finally {
if (pushed) {
popCompositeComponent(ctx);
}
}
}
public boolean isReadOnly(ELContext elContext) {
FacesContext ctx = (FacesContext) elContext.getContext(FacesContext.class);
boolean pushed = pushCompositeComponent(ctx);
try {
return originalVE.isReadOnly(elContext);
} finally {
if (pushed) {
popCompositeComponent(ctx);
}
}
}
public Class> getType(ELContext elContext) {
FacesContext ctx = (FacesContext) elContext.getContext(FacesContext.class);
boolean pushed = pushCompositeComponent(ctx);
try {
return originalVE.getType(elContext);
} finally {
if (pushed) {
popCompositeComponent(ctx);
}
}
}
public Class> getExpectedType() {
FacesContext ctx = FacesContext.getCurrentInstance();
boolean pushed = pushCompositeComponent(ctx);
try {
return originalVE.getExpectedType();
} finally {
if (pushed) {
popCompositeComponent(ctx);
}
}
}
// --------------------------------------------- Methods from Expression
public String getExpressionString() {
return originalVE.getExpressionString();
}
@SuppressWarnings({"EqualsWhichDoesntCheckParameterClass"})
public boolean equals(Object o) {
return originalVE.equals(o);
}
public int hashCode() {
return originalVE.hashCode();
}
public boolean isLiteralText() {
return originalVE.isLiteralText();
}
@Override
public String toString() {
return originalVE.toString();
}
// ------------------------------------------------------ Public Methods
/**
* @return the {@link Location} of this ValueExpression
*/
public Location getLocation() {
return location;
}
// ----------------------------------------------------- Private Methods
private boolean pushCompositeComponent(FacesContext ctx) {
CompositeComponentStackManager manager =
CompositeComponentStackManager.getManager(ctx);
UIComponent cc = manager.findCompositeComponentUsingLocation(ctx, location);
return manager.push(cc);
}
private void popCompositeComponent(FacesContext ctx) {
CompositeComponentStackManager manager =
CompositeComponentStackManager.getManager(ctx);
manager.pop();
}
} // END ContextualCompositeValueExpression