/*
* $Id: OptionsTag.java 190807 2005-06-15 21:01:56Z jholmes $
*
* Copyright 1999-2004 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 org.apache.struts.taglib.html;
import java.lang.reflect.InvocationTargetException;
import java.util.Arrays;
import java.util.Collection;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Map;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;
import org.apache.commons.beanutils.PropertyUtils;
import org.apache.struts.util.IteratorAdapter;
import org.apache.struts.taglib.TagUtils;
import org.apache.struts.util.MessageResources;
/**
* 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.
*
*/
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;
}
/**
* Should the label values be filtered for HTML sensitive characters?
*/
protected boolean filter = true;
public boolean getFilter() {
return filter;
}
public void setFilter(boolean filter) {
this.filter = filter;
}
/**
* 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;
}
/**
* The style associated with this tag.
*/
private String style = null;
public String getStyle() {
return style;
}
public void setStyle(String style) {
this.style = style;
}
/**
* The named style class associated with this tag.
*/
private String styleClass = null;
public String getStyleClass() {
return styleClass;
}
public void setStyleClass(String styleClass) {
this.styleClass = styleClass;
}
/**
* 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 = "";
}
} 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));
}
try {
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", labelProperty, collection));
} catch (InvocationTargetException e) {
Throwable t = e.getTargetException();
throw new JspException(
messages.getMessage("getter.result", labelProperty, t.toString()));
} catch (NoSuchMethodException e) {
throw new JspException(
messages.getMessage("getter.method", labelProperty, 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(labelName, labelProperty);
}
// Render the options tags for each element of the values coll.
while (valuesIterator.hasNext()) {
Object valueObject = valuesIterator.next();
if (valueObject == null) {
valueObject = "";
}
String value = valueObject.toString();
String label = value;
if ((labelsIterator != null) && labelsIterator.hasNext()) {
Object labelObject = labelsIterator.next();
if (labelObject == null) {
labelObject = "";
}
label = labelObject.toString();
}
addOption(sb, value, label, selectTag.isMatched(value));
}
}
TagUtils.getInstance().write(pageContext, sb.toString());
return EVAL_PAGE;
}
/**
* Release any acquired resources.
*/
public void release() {
super.release();
collection = null;
filter = true;
labelName = null;
labelProperty = null;
name = null;
property = null;
style = null;
styleClass = null;
}
// ------------------------------------------------------ Protected Methods
/**
* Add an option element to the specified StringBuffer based on the
* specified parameters.
*<p>
* Note that this tag specifically does not support the
* <code>styleId</code> tag attribute, which causes the HTML
* <code>id</code> attribute to be emitted. This is because the HTML
* specification states that all "id" attributes in a document have to be
* unique. This tag will likely generate more than one <code>option</code>
* element element, but it cannot use the same <code>id</code> value. It's
* conceivable some sort of mechanism to supply an array of <code>id</code>
* values could be devised, but that doesn't seem to be worth the trouble.
*
* @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=\"");
if (filter) {
sb.append(TagUtils.getInstance().filter(value));
} else {
sb.append(value);
}
sb.append("\"");
if (matched) {
sb.append(" selected=\"selected\"");
}
if (style != null) {
sb.append(" style=\"");
sb.append(style);
sb.append("\"");
}
if (styleClass != null) {
sb.append(" class=\"");
sb.append(styleClass);
sb.append("\"");
}
sb.append(">");
if (filter) {
sb.append(TagUtils.getInstance().filter(label));
} else {
sb.append(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 = TagUtils.getInstance().lookup(pageContext, beanName, null);
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);
if (collection == null) {
throw new JspException(messages.getMessage("getter.property", 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()));
}
}
}