/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.cocoon.forms.datatype;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.Iterator;
import java.util.Locale;
import org.apache.cocoon.forms.FormsConstants;
import org.apache.cocoon.xml.AttributesImpl;
import org.apache.cocoon.xml.XMLUtils;
import org.apache.commons.lang.enums.Enum;
import org.apache.commons.lang.enums.EnumUtils;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
/**
* This type of selection list outputs a list of items
* corresponding to the possible instances of an {@link org.apache.cocoon.forms.datatype.typeimpl.EnumType}.
* <p>Example usage:</p>
* <pre>
* <fd:selection-list type="enum" class="com.example.Sex"/>
* </pre>
* <p>Produces the following output:</p>
* <pre>
* <fi:selection-list>
* <fi:item value=""/>
* <fi:item value="com.example.Sex.MALE">
* <fi:label>
* <i18n:text>com.example.Sex.MALE</i18n:text>
* </fi:label>
* </fi:item>
* <fi:item value="com.example.Sex.FEMALE">
* <fi:label>
* <i18n:text>com.example.Sex.FEMALE</i18n:text>
* </fi:label>
* </fi:item>
* </fi:selection-list>
* </pre>
*
* <p>If you don't want an initial null value, add a
* <code>nullable="false"</code> attribute to the
* <code>fd:selection-list</code> element.</p>
*
* @version $Id$
*/
public class EnumSelectionList implements SelectionList {
public static final String TEXT_EL = "text";
private Datatype datatype;
private Class clazz;
private boolean nullable;
private String nullText;
/**
* @param className
* @param datatype
*/
public EnumSelectionList(String className, Datatype datatype, boolean nullable) throws ClassNotFoundException {
this.datatype = datatype;
this.nullable = nullable;
this.clazz = Class.forName(className);
}
public EnumSelectionList(String className, Datatype datatype, boolean nullable, String nullText) throws ClassNotFoundException {
this(className, datatype, nullable);
this.nullText = nullText;
}
/* (non-Javadoc)
* @see org.apache.cocoon.forms.datatype.SelectionList#getDatatype()
*/
public Datatype getDatatype() {
return datatype;
}
/* (non-Javadoc)
* @see org.apache.cocoon.forms.datatype.SelectionList#generateSaxFragment(org.xml.sax.ContentHandler, java.util.Locale)
*/
public void generateSaxFragment(ContentHandler contentHandler,
Locale locale)
throws SAXException {
try {
contentHandler.startElement(FormsConstants.INSTANCE_NS, SELECTION_LIST_EL, FormsConstants.INSTANCE_PREFIX_COLON + SELECTION_LIST_EL, XMLUtils.EMPTY_ATTRIBUTES);
// Create void element
if (nullable) {
AttributesImpl voidAttrs = new AttributesImpl();
voidAttrs.addCDATAAttribute("value", "");
contentHandler.startElement(FormsConstants.INSTANCE_NS, ITEM_EL, FormsConstants.INSTANCE_PREFIX_COLON + ITEM_EL, voidAttrs);
if (this.nullText != null) {
contentHandler.startElement(FormsConstants.INSTANCE_NS, LABEL_EL, FormsConstants.INSTANCE_PREFIX_COLON + LABEL_EL, XMLUtils.EMPTY_ATTRIBUTES);
contentHandler.startElement(FormsConstants.I18N_NS, TEXT_EL, FormsConstants.I18N_PREFIX_COLON + TEXT_EL, XMLUtils.EMPTY_ATTRIBUTES);
contentHandler.characters(nullText.toCharArray(), 0, nullText.length());
contentHandler.endElement(FormsConstants.I18N_NS, TEXT_EL, FormsConstants.I18N_PREFIX_COLON + TEXT_EL);
contentHandler.endElement(FormsConstants.INSTANCE_NS, LABEL_EL, FormsConstants.INSTANCE_PREFIX_COLON + LABEL_EL);
}
contentHandler.endElement(FormsConstants.INSTANCE_NS, ITEM_EL, FormsConstants.INSTANCE_PREFIX_COLON + ITEM_EL);
}
// Test if we have an apache enum class
boolean apacheEnumDone = false;
if (Enum.class.isAssignableFrom(clazz)) {
Iterator iter = EnumUtils.iterator(clazz);
if (iter != null) {
apacheEnumDone = true;
while (iter.hasNext()) {
Enum element = (Enum) iter.next();
String stringValue = clazz.getName() + "." + element.getName();
generateItem(contentHandler, stringValue);
}
}
}
// If it's not an apache enum or we didn't manage to read the enum list, then proceed with common method.
if (!apacheEnumDone) {
Field fields[] = clazz.getDeclaredFields();
for (int i = 0 ; i < fields.length ; ++i) {
int mods = fields[i].getModifiers();
if (Modifier.isPublic(mods) && Modifier.isStatic(mods)
&& Modifier.isFinal(mods) && fields[i].get(null).getClass().equals(clazz)) {
String stringValue = clazz.getName() + "." + fields[i].getName();
generateItem(contentHandler, stringValue);
}
}
}
// End the selection-list
contentHandler.endElement(FormsConstants.INSTANCE_NS, SELECTION_LIST_EL, FormsConstants.INSTANCE_PREFIX_COLON + SELECTION_LIST_EL);
} catch (Exception e) {
throw new SAXException("Got exception trying to get enum's values", e);
}
}
/**
* Generates a single selection list item.
* @param contentHandler The content handler we are streaming sax events to.
* @param stringValue The string name of the item, composed by FQN and enum item.
* @throws SAXException
*/
private void generateItem(ContentHandler contentHandler, String stringValue) throws SAXException {
// Output this item
AttributesImpl itemAttrs = new AttributesImpl();
itemAttrs.addCDATAAttribute("value", stringValue);
contentHandler.startElement(FormsConstants.INSTANCE_NS, ITEM_EL, FormsConstants.INSTANCE_PREFIX_COLON + ITEM_EL, itemAttrs);
contentHandler.startElement(FormsConstants.INSTANCE_NS, LABEL_EL, FormsConstants.INSTANCE_PREFIX_COLON + LABEL_EL, XMLUtils.EMPTY_ATTRIBUTES);
// TODO: make i18n element optional
contentHandler.startElement(FormsConstants.I18N_NS, TEXT_EL, FormsConstants.I18N_PREFIX_COLON + TEXT_EL, XMLUtils.EMPTY_ATTRIBUTES);
contentHandler.characters(stringValue.toCharArray(), 0, stringValue.length());
contentHandler.endElement(FormsConstants.I18N_NS, TEXT_EL, FormsConstants.I18N_PREFIX_COLON + TEXT_EL);
contentHandler.endElement(FormsConstants.INSTANCE_NS, LABEL_EL, FormsConstants.INSTANCE_PREFIX_COLON + LABEL_EL);
contentHandler.endElement(FormsConstants.INSTANCE_NS, ITEM_EL, FormsConstants.INSTANCE_PREFIX_COLON + ITEM_EL);
}
}