/*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999-2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Struts", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
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*
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.struts.taglib.html;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.TagSupport;
import org.apache.struts.util.IteratorAdapter;
import org.apache.struts.util.MessageResources;
import org.apache.struts.util.PropertyUtils;
import org.apache.struts.util.ResponseUtils;
import java.util.Arrays;
import java.util.Collection;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Map;
/**
* Tag for creating multiple <select> options from a collection. The
* associated values displayed to the user may optionally be specified by a
* second collection, or will be the same as the values themselves. Each
* collection may be an array of objects, a Collection, an Enumeration,
* an Iterator, or a Map.
* <b>NOTE</b> - This tag requires a Java2 (JDK 1.2 or later) platform.
*
* @author Florent Carpentier
* @author Craig McClanahan
*/
public class OptionsTag extends TagSupport {
/**
* The message resources for this package.
*/
protected static MessageResources messages =
MessageResources.getMessageResources(Constants.Package + ".LocalStrings");
/**
* The name of the collection containing beans that have properties to
* provide both the values and the labels (identified by the
* <code>property</code> and <code>labelProperty</code> attributes).
*/
protected String collection = null;
public String getCollection() {
return (this.collection);
}
public void setCollection(String collection) {
this.collection = collection;
}
/**
* The name of the bean containing the labels collection.
*/
protected String labelName = null;
public String getLabelName() {
return labelName;
}
public void setLabelName(String labelName) {
this.labelName = labelName;
}
/**
* The bean property containing the labels collection.
*/
protected String labelProperty = null;
public String getLabelProperty() {
return labelProperty;
}
public void setLabelProperty(String labelProperty) {
this.labelProperty = labelProperty;
}
/**
* The name of the bean containing the values collection.
*/
protected String name=null;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
/**
* The name of the property to use to build the values collection.
*/
protected String property=null;
public String getProperty() {
return property;
}
public void setProperty(String property) {
this.property = property;
}
/**
* Process the start of this tag.
*
* @exception JspException if a JSP exception has occurred
*/
public int doStartTag() throws JspException {
return SKIP_BODY;
}
/**
* Process the end of this tag.
*
* @exception JspException if a JSP exception has occurred
*/
public int doEndTag() throws JspException {
// Acquire the select tag we are associated with
SelectTag selectTag =
(SelectTag) pageContext.getAttribute(Constants.SELECT_KEY);
if (selectTag == null)
throw new JspException
(messages.getMessage("optionsTag.select"));
StringBuffer sb = new StringBuffer();
// If a collection was specified, use that mode to render options
if (collection != null) {
Iterator collIterator = getIterator(collection, null);
while (collIterator.hasNext()) {
Object bean = collIterator.next();
Object value = null;
Object label = null;;
try {
value = PropertyUtils.getProperty(bean, property);
if (value == null)
value = "";
if (labelProperty != null)
label =
PropertyUtils.getProperty(bean, labelProperty);
else
label = value;
if (label == null)
label = "";
} catch (IllegalAccessException e) {
throw new JspException
(messages.getMessage("getter.access",
property, collection));
} catch (InvocationTargetException e) {
Throwable t = e.getTargetException();
throw new JspException
(messages.getMessage("getter.result",
property, t.toString()));
} catch (NoSuchMethodException e) {
throw new JspException
(messages.getMessage("getter.method",
property, collection));
}
String stringValue = value.toString();
addOption(sb, stringValue, label.toString(),
selectTag.isMatched(stringValue));
}
}
// Otherwise, use the separate iterators mode to render options
else {
// Construct iterators for the values and labels collections
Iterator valuesIterator = getIterator(name, property);
Iterator labelsIterator = null;
if ((labelName == null) && (labelProperty == null))
labelsIterator = getIterator(name, property); // Same coll.
else
labelsIterator = getIterator(labelName, labelProperty);
// Render the options tags for each element of the values coll.
while (valuesIterator.hasNext()) {
String value = (String) valuesIterator.next();
String label = value;
if (labelsIterator.hasNext())
label = (String) labelsIterator.next();
addOption(sb, value, label,
selectTag.isMatched(value));
}
}
// Render this element to our writer
ResponseUtils.write(pageContext, sb.toString());
// Evaluate the remainder of this page
return EVAL_PAGE;
}
/**
* Release any acquired resources.
*/
public void release() {
super.release();
collection = null;
labelName = null;
labelProperty = null;
name = null;
property = null;
}
// ------------------------------------------------------ Protected Methods
/**
* Add an option element to the specified StringBuffer based on the
* specified parameters.
*
* @param sb StringBuffer accumulating our results
* @param value Value to be returned to the server for this option
* @param label Value to be shown to the user for this option
* @param matched Should this value be marked as selected?
*/
protected void addOption(StringBuffer sb, String value, String label,
boolean matched) {
sb.append("<option value=\"");
sb.append(value);
sb.append("\"");
if (matched)
sb.append(" selected");
sb.append(">");
sb.append(ResponseUtils.filter(label));
sb.append("</option>\r\n");
}
/**
* Return an iterator for the option labels or values, based on our
* configured properties.
*
* @param name Name of the bean attribute (if any)
* @param property Name of the bean property (if any)
*
* @exception JspException if an error occurs
*/
protected Iterator getIterator(String name, String property)
throws JspException {
// Identify the bean containing our collection
String beanName = name;
if (beanName == null)
beanName = Constants.BEAN_KEY;
Object bean = pageContext.findAttribute(beanName);
if (bean == null)
throw new JspException
(messages.getMessage("getter.bean", beanName));
// Identify the collection itself
Object collection = bean;
if (property != null) {
try {
collection = PropertyUtils.getProperty(bean, property);
} catch (IllegalAccessException e) {
throw new JspException
(messages.getMessage("getter.access", property, name));
} catch (InvocationTargetException e) {
Throwable t = e.getTargetException();
throw new JspException
(messages.getMessage("getter.result",
property, t.toString()));
} catch (NoSuchMethodException e) {
throw new JspException
(messages.getMessage("getter.method", property, name));
}
}
// Construct and return an appropriate iterator
if (collection.getClass().isArray())
collection = Arrays.asList((Object[]) collection);
if (collection instanceof Collection)
return (((Collection) collection).iterator());
else if (collection instanceof Iterator)
return ((Iterator) collection);
else if (collection instanceof Map)
return (((Map) collection).entrySet().iterator());
else if (collection instanceof Enumeration)
return( new IteratorAdapter((Enumeration)collection));
else
throw new JspException
(messages.getMessage("optionsTag.iterator",
collection.toString()));
}
}