com.sun.faces.taglib.jsf_core.SetPropertyActionListenerTag Maven / Gradle / Ivy
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/*
* 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.taglib.jsf_core;
import com.sun.faces.util.MessageUtils;
import jakarta.el.ValueExpression;
import jakarta.faces.component.ActionSource;
import jakarta.faces.component.UIComponent;
import jakarta.faces.event.ActionListener;
import jakarta.faces.webapp.UIComponentClassicTagBase;
import jakarta.faces.webapp.UIComponentELTag;
import jakarta.servlet.jsp.JspException;
import jakarta.servlet.jsp.tagext.TagSupport;
/**
*
* Tag implementation that creates a special {@link ActionListener} instance and registers it on the
* {@link ActionSource} associated with our most immediate surrounding instance of a tag whose implementation class is a
* subclass of {@link UIComponentClassicTagBase}. This tag creates no output to the page currently being created.
*
*
*
* The ActionListener instance created and installed by this tag has the following behavior and contract.
*
*
*
*
* - Only create and register the
ActionListener instance the first time the component for this tag is
* created
*
* - The "target" and "value" tag attributes are ValueExpression instances and are stored unevaluated as instance
* variables of the listener.
*
* - When the listener executes, call getValue() on the "value" ValueExpression. Pass the result to a call to
* setValue() on the "target" ValueExpression
*
*
*
*
* This tag creates no output to the page currently being created. It is used solely for the side effect of
* {@link ActionListener} creation.
*
*/
public class SetPropertyActionListenerTag extends TagSupport {
// ------------------------------------------------------------- Attributes
static final long serialVersionUID = 7966883942522780374L;
/**
*
* The target of the value attribute.
*
*/
private ValueExpression target = null;
/**
*
* The value that is set into the target attribute.
*
*/
private ValueExpression value = null;
/**
*
* Setter for the target attribute
*
*
* @param target The new class name
*/
public void setTarget(ValueExpression target) {
this.target = target;
}
/*
* Setter for the value attribute
*
* @param value The new value value expression
*
* @throws JspException if a JSP error occurs
*/
public void setValue(ValueExpression value) {
this.value = value;
}
// --------------------------------------------------------- Public Methods
/**
*
* Create a new instance of the {@link ActionListener} class, and register it with the {@link UIComponent} instance
* associated with our most immediately surrounding {@link UIComponentClassicTagBase} instance. The behavior of the
* {@link ActionListener} must conform to the class description.
*
*
* @throws JspException if a JSP error occurs
*/
@Override
public int doStartTag() throws JspException {
// Locate our parent UIComponentTag
UIComponentClassicTagBase tag = UIComponentELTag.getParentUIComponentClassicTagBase(pageContext);
if (tag == null) {
Object params[] = { this.getClass().getName() };
throw new JspException(MessageUtils.getExceptionMessageString(MessageUtils.NOT_NESTED_IN_FACES_TAG_ERROR_MESSAGE_ID, params));
}
// Nothing to do unless this tag created a component
if (!tag.getCreated()) {
return SKIP_BODY;
}
UIComponent component = tag.getComponentInstance();
if (component == null) {
throw new JspException(MessageUtils.getExceptionMessageString(MessageUtils.NULL_COMPONENT_ERROR_MESSAGE_ID));
}
if (!(component instanceof ActionSource)) {
Object params[] = { "setPropertyActionListener", "jakarta.faces.component.ActionSource" };
throw new JspException(MessageUtils.getExceptionMessageString(MessageUtils.NOT_NESTED_IN_TYPE_TAG_ERROR_MESSAGE_ID, params));
}
ActionListener handler = new SetPropertyActionListenerImpl(target, value);
((ActionSource) component).addActionListener(handler);
return SKIP_BODY;
}
/**
*
* Release references to any acquired resources.
*/
@Override
public void release() {
value = null;
target = null;
}
}