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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 jakarta.faces.webapp;
import jakarta.el.ValueExpression;
import jakarta.faces.component.UIComponent;
import jakarta.faces.component.ValueHolder;
import jakarta.faces.context.FacesContext;
import jakarta.faces.convert.Converter;
import jakarta.faces.convert.ConverterException;
import jakarta.servlet.jsp.JspException;
import jakarta.servlet.jsp.tagext.TagSupport;
/**
*
* ConverterTag is a base class for all Jakarta Server Pages custom actions that create and register a
* Converter instance on the {@link ValueHolder} associated with our most immediate surrounding instance of
* a tag whose implementation class is a subclass of {@link UIComponentTag}. To avoid creating duplicate instances when
* a page is redisplayed, creation and registration of a {@link Converter} occurs only if the
* corresponding {@link UIComponent} was created (by the owning {@link UIComponentTag}) during the execution of the
* current page.
*
*
*
* This class may be used directly to implement a generic converter registration tag (based on the converter-id
* specified by the converterId attribute), or as a base class for tag instances that support specific
* {@link Converter} subclasses. This converterId attribute must refer to one of the well known
* converter-ids, or a custom converter-id as defined in a faces-config.xml file.
*
*
*
* Subclasses of this class must implement the createConverter() method, which creates and returns a
* {@link Converter} instance. Any configuration properties that specify behavior of this {@link Converter} must have
* been set by the createConverter() method. Generally, this occurs by copying corresponding attribute
* values on the tag instance.
*
*
*
* This tag creates no output to the page currently being created. It is used solely for the side effect of
* {@link Converter} creation.
*
*
* @deprecated This has been partially replaced by {@link ConverterELTag}. The remainder of the functionality, namely,
* the binding facility and the implementation of the {@link #createConverter} method, is now an implementation detail.
*/
@Deprecated
public class ConverterTag extends TagSupport {
// ---------------------------------------------------------- Static Members
private static final long serialVersionUID = -5909792518081427720L;
// -------------------------------------------------------------- Attributes
/**
*
* The identifier of the {@link Converter} instance to be created.
*
*/
private String converterId = null;
/**
*
* The {@link ValueExpression} that evaluates to an object that implements {@link Converter}.
*
*/
private String binding = null;
/**
*
* Set the identifer of the {@link Converter} instance to be created.
*
* @param converterId The identifier of the converter instance to be created.
*/
public void setConverterId(String converterId) {
this.converterId = converterId;
}
/**
*
* Set the expression that will be used to create a {@link ValueExpression} that references a backing bean property of
* the {@link Converter} instance to be created.
*
*
* @param binding The new expression
*
* @throws JspException if a Jakarta Server Pages error occurs
*/
public void setBinding(String binding) throws JspException {
if (binding != null && !UIComponentTag.isValueReference(binding)) {
// PENDING i18n
throw new JspException("Invalid Expression:" + binding);
}
this.binding = binding;
}
// ---------------------------------------------------------- Public Methods
/**
*
* Create a new instance of the specified {@link Converter} class, and register it with the {@link UIComponent} instance
* associated with our most immediately surrounding {@link UIComponentTag} instance, if the {@link UIComponent} instance
* was created by this execution of the containing Jakarta Server Pages page. If the localValue of the
* {@link UIComponent} is a String, attempt to convert it.
*
*
* @throws JspException if a Jakarta Server Pages error occurs
*/
@Override
public int doStartTag() throws JspException {
// Locate our parent UIComponentTag
UIComponentClassicTagBase tag = UIComponentClassicTagBase.getParentUIComponentClassicTagBase(pageContext);
if (tag == null) { // PENDING - i18n
throw new JspException("Not nested in a UIComponentTag Error for tag with handler class:" + this.getClass().getName());
}
// Nothing to do unless this tag created a component
if (!tag.getCreated()) {
return SKIP_BODY;
}
UIComponent component = tag.getComponentInstance();
if (component == null) {
// PENDING i18n
throw new JspException("Can't create Component from tag.");
}
if (!(component instanceof ValueHolder)) {
// PENDING i18n
throw new JspException("Not nested in a tag of proper type. Error for tag with handler class:" + this.getClass().getName());
}
Converter converter = createConverter();
if (converter == null) {
// noinspection NonConstantStringShouldBeStringBuffer
String converterError = null;
if (binding != null) {
converterError = binding;
}
if (converterId != null) {
if (converterError != null) {
converterError += " or " + converterId;
} else {
converterError = converterId;
}
}
// PENDING i18n
throw new JspException("Can't create class of type:" + "jakarta.faces.convert.Converter for:" + converterError);
}
ValueHolder vh = (ValueHolder) component;
FacesContext context = FacesContext.getCurrentInstance();
// Register an instance with the appropriate component
vh.setConverter(converter);
// Once the converter has been set, attempt to convert the
// incoming "value"
Object localValue = vh.getLocalValue();
if (localValue instanceof String) {
try {
localValue = converter.getAsObject(context, (UIComponent) vh, (String) localValue);
vh.setValue(localValue);
} catch (ConverterException ce) {
// PENDING - Ignore? Throw an exception? Set the local
// value back to "null" and log a warning?
}
}
return SKIP_BODY;
}
/**
*
* Release references to any acquired resources.
*/
@Override
public void release() {
converterId = null;
}
// ------------------------------------------------------- Protected Methods
/**
*
* Create and return a new {@link Converter} to be registered on our surrounding {@link UIComponent}.
*
*
* @throws JspException if a new instance cannot be created
*
* @return the {@code Converter}
*/
protected Converter createConverter() throws JspException {
FacesContext context = FacesContext.getCurrentInstance();
Converter converter = null;
ValueExpression vb = null;
// If "binding" is set, use it to create a converter instance.
if (binding != null) {
try {
vb = context.getApplication().getExpressionFactory().createValueExpression(context.getELContext(), binding, Object.class);
if (vb != null) {
converter = (Converter) vb.getValue(context.getELContext());
if (converter != null) {
return converter;
}
}
} catch (Exception e) {
throw new JspException(e);
}
}
// If "converterId" is set, use it to create the converter
// instance. If "converterId" and "binding" are both set, store the
// converter instance in the value of the property represented by
// the value binding expression.
if (converterId != null) {
try {
String converterIdVal = converterId;
if (UIComponentTag.isValueReference(converterId)) {
ValueExpression idBinding = context.getApplication().getExpressionFactory().createValueExpression(context.getELContext(), converterId,
Object.class);
converterIdVal = (String) idBinding.getValue(context.getELContext());
}
converter = context.getApplication().createConverter(converterIdVal);
if (converter != null) {
if (vb != null) {
vb.setValue(context.getELContext(), converter);
}
}
} catch (Exception e) {
throw new JspException(e);
}
}
return converter;
}
}