/*
* $Id: OptionsCollectionTag.java 56513 2004-11-03 19:20:47Z niallp $
*
* Copyright 2002-2004 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
* collection may be part of the enclosing form, or may be independent of
* the form. Each element of the collection must expose a 'label' and a
* 'value', the property names of which are configurable by attributes of
* this tag.
* <p>
* The collection may be an array of objects, a Collection, an Enumeration,
* an Iterator, or a Map.
* <p>
* <b>NOTE</b> - This tag requires a Java2 (JDK 1.2 or later) platform.
*
* @version $Rev: 56513 $ $Date: 2004-11-03 19:20:47 +0000 (Wed, 03 Nov 2004) $
* @since Struts 1.1
*/
public class OptionsCollectionTag extends TagSupport {
// ----------------------------------------------------- Instance Variables
/**
* The message resources for this package.
*/
protected static MessageResources messages =
MessageResources.getMessageResources(Constants.Package + ".LocalStrings");
// ------------------------------------------------------------- Properties
/**
* 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 property containing the label.
*/
protected String label = "label";
public String getLabel() {
return label;
}
public void setLabel(String label) {
this.label = label;
}
/**
* The name of the bean containing the values collection.
*/
protected String name = Constants.BEAN_KEY;
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;
}
/**
* The name of the bean property containing the value.
*/
protected String value = "value";
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
// --------------------------------------------------------- Public Methods
/**
* Process the start of this tag.
*
* @exception JspException if a JSP exception has occurred
*/
public int doStartTag() throws JspException {
// Acquire the select tag we are associated with
SelectTag selectTag = (SelectTag) pageContext.getAttribute(Constants.SELECT_KEY);
if (selectTag == null) {
JspException e = new JspException(messages.getMessage("optionsCollectionTag.select"));
TagUtils.getInstance().saveException(pageContext, e);
throw e;
}
// Acquire the collection containing our options
Object collection = TagUtils.getInstance().lookup(pageContext, name, property, null);
if (collection == null) {
JspException e =
new JspException(messages.getMessage("optionsCollectionTag.collection"));
TagUtils.getInstance().saveException(pageContext, e);
throw e;
}
// Acquire an iterator over the options collection
Iterator iter = getIterator(collection);
StringBuffer sb = new StringBuffer();
// Render the options
while (iter.hasNext()) {
Object bean = iter.next();
Object beanLabel = null;
Object beanValue = null;
// Get the label for this option
try {
beanLabel = PropertyUtils.getProperty(bean, label);
if (beanLabel == null) {
beanLabel = "";
}
} catch (IllegalAccessException e) {
JspException jspe =
new JspException(messages.getMessage("getter.access", label, bean));
TagUtils.getInstance().saveException(pageContext, jspe);
throw jspe;
} catch (InvocationTargetException e) {
Throwable t = e.getTargetException();
JspException jspe =
new JspException(messages.getMessage("getter.result", label, t.toString()));
TagUtils.getInstance().saveException(pageContext, jspe);
throw jspe;
} catch (NoSuchMethodException e) {
JspException jspe =
new JspException(messages.getMessage("getter.method", label, bean));
TagUtils.getInstance().saveException(pageContext, jspe);
throw jspe;
}
// Get the value for this option
try {
beanValue = PropertyUtils.getProperty(bean, value);
if (beanValue == null) {
beanValue = "";
}
} catch (IllegalAccessException e) {
JspException jspe =
new JspException(messages.getMessage("getter.access", value, bean));
TagUtils.getInstance().saveException(pageContext, jspe);
throw jspe;
} catch (InvocationTargetException e) {
Throwable t = e.getTargetException();
JspException jspe =
new JspException(messages.getMessage("getter.result", value, t.toString()));
TagUtils.getInstance().saveException(pageContext, jspe);
throw jspe;
} catch (NoSuchMethodException e) {
JspException jspe =
new JspException(messages.getMessage("getter.method", value, bean));
TagUtils.getInstance().saveException(pageContext, jspe);
throw jspe;
}
String stringLabel = beanLabel.toString();
String stringValue = beanValue.toString();
// Render this option
addOption(sb, stringLabel, stringValue, selectTag.isMatched(stringValue));
}
TagUtils.getInstance().write(pageContext, sb.toString());
return SKIP_BODY;
}
/**
* Release any acquired resources.
*/
public void release() {
super.release();
filter = true;
label = "label";
name = Constants.BEAN_KEY;
property = null;
style = null;
styleClass = null;
value = "value";
}
// ------------------------------------------------------ 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 label, String value, 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 options collection.
*
* @param collection Collection to be iterated over
*
* @exception JspException if an error occurs
*/
protected Iterator getIterator(Object collection) throws JspException {
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("optionsCollectionTag.iterator", collection.toString()));
}
}
}