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EE4J Compatible Implementation for Jakarta Faces API
/*
* Copyright (c) 1997, 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 javax.faces.webapp;
import javax.faces.application.Application;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.el.ValueBinding;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.Tag;
/**
* {@link UIComponentTag} is the base class for all Jakarta Server Pages custom
* actions that correspond to user interface components in a page that is
* rendered by Jakarta Server Faces.
*
* In this version of the specification, UIComponentTag
* extends {@link UIComponentClassicTagBase} to add properties that use
* the Faces 1.1 Expression Language.
*
* @deprecated Use of this class has been replaced with {@link
* UIComponentELTag}, which extends
* UIComponentClassicTagBase to add properties that use the
* Jakarta Expression Language API introduced as part of Jakarta Server Pages 2.1.
*/
public abstract class UIComponentTag extends UIComponentClassicTagBase implements Tag {
// ------------------------------------------------------------- Properties
/**
* The value binding expression (if any) used to wire up this component
* to a {@link UIComponent} property of a JavaBean class.
*/
private String binding = null;
/**
* Set the value binding expression for our component.
*
* @param binding The new value binding expression
*
* @throws IllegalArgumentException if the specified binding is not a
* valid value binding expression.
*
* @throws JspException if the binding cannot be set
*/
public void setBinding(String binding) throws JspException {
if (!isValueReference(binding)) {
throw new IllegalArgumentException();
}
this.binding = binding;
}
@Override
protected boolean hasBinding() {
return null != binding;
}
/**
* An override for the rendered attribute associated with our
* {@link UIComponent}.
*/
private String rendered = null;
/**
* Set an override for the rendered attribute.
*
* @param rendered The new value for rendered attribute
*/
public void setRendered(String rendered) {
this.rendered = rendered;
}
/**
* Flag indicating whether or not rendering should occur.
*/
private boolean suppressed = false;
protected boolean isSuppressed() {
return (suppressed);
}
/**
* Return true if the specified value conforms to the
* syntax requirements of a value binding expression. Such expressions
` * may be used on most component tag attributes to signal a desire for
* deferred evaluation of the attribute or property value to be set on
* the underlying {@link UIComponent}.
*
* @param value The value to evaluate
*
* @throws NullPointerException if value is
* null
*
* @return whether or not this value has the correct syntax for a
* value binding expression
*/
public static boolean isValueReference(String value) {
if (value == null) {
throw new NullPointerException();
}
int start = value.indexOf("#{");
if ((start != -1) && (start < value.indexOf('}', start))) {
return true;
}
return false;
}
// ------------------------------------------ Methods from Tag
/**
* Release any resources allocated during the execution of this
* tag handler.
*/
@Override
public void release() {
this.suppressed = false;
this.binding = null;
this.rendered = null;
super.release();
}
// ---------------- Concrete Implementations of methods from superclass
/**
* @param component {@inheritDoc}
*/
@Override
protected void setProperties(UIComponent component) {
// The "id" property is explicitly set when components are created
// so it does not need to be set here
if (rendered != null) {
if (isValueReference(rendered)) {
ValueBinding vb =
getFacesContext().getApplication().createValueBinding(rendered);
component.setValueBinding("rendered", vb);
} else {
component.setRendered(Boolean.valueOf(rendered).booleanValue());
}
}
if (getRendererType() != null) {
component.setRendererType(getRendererType());
}
}
/**
* Implement createComponent using Faces 1.1 EL
* API.
*
* @param context {@inheritDoc}
* @param newId {@inheritDoc}
*/
@Override
protected UIComponent createComponent(FacesContext context, String newId) {
UIComponent component;
Application application = context.getApplication();
if (binding != null) {
ValueBinding vb = application.createValueBinding(binding);
component = application.createComponent(vb, context,
getComponentType());
component.setValueBinding("binding", vb);
} else {
component = application.createComponent(getComponentType());
}
component.setId(newId);
setProperties(component);
return component;
}
// Tag tree navigation
/**
* Locate and return the nearest enclosing {@link UIComponentTag}
* if any; otherwise, return null.
*
* @param context PageContext for the current page
*
* @return the parent tag
*/
public static UIComponentTag getParentUIComponentTag(PageContext context) {
UIComponentClassicTagBase result =
getParentUIComponentClassicTagBase(context);
if (!(result instanceof UIComponentTag)) {
return new UIComponentTagAdapter(result);
}
return ((UIComponentTag) result);
}
// --------------------------------------------------------- Private Classes
/**
* This adatper exposes a UIComponentClassicTagBase as a UIComponentTag
* for 1.1 component libraries that rely on UIComponent.getParentUIComponentTag().
*
* This will work for most use cases, but there are probably some edge
* cases out there that we're not aware of.
*/
private static class UIComponentTagAdapter extends UIComponentTag {
UIComponentClassicTagBase classicDelegate;
public UIComponentTagAdapter(UIComponentClassicTagBase classicDelegate) {
this.classicDelegate = classicDelegate;
}
@Override
public String getComponentType() {
return classicDelegate.getComponentType();
}
@Override
public String getRendererType() {
return classicDelegate.getRendererType();
}
@Override
public int doStartTag() throws JspException {
throw new IllegalStateException();
}
@Override
public int doEndTag() throws JspException {
throw new IllegalStateException();
}
@Override
public UIComponent getComponentInstance() {
return classicDelegate.getComponentInstance();
}
@Override
public boolean getCreated() { // NOPMD
return classicDelegate.getCreated();
}
@Override
public Tag getParent() {
return classicDelegate.getParent();
}
@Override
public void setParent(Tag parent) {
throw new IllegalStateException();
}
}
}