/*
* 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.lenya.modules.metadata;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.avalon.framework.activity.Disposable;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.environment.Request;
import org.apache.cocoon.environment.SourceResolver;
import org.apache.cocoon.transformation.AbstractSAXTransformer;
import org.apache.lenya.cms.metadata.MetaData;
import org.apache.lenya.cms.publication.Area;
import org.apache.lenya.cms.publication.Document;
import org.apache.lenya.cms.publication.DocumentFactory;
import org.apache.lenya.cms.publication.DocumentUtil;
import org.apache.lenya.cms.publication.Publication;
import org.apache.lenya.cms.publication.PublicationException;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
/**
* <p>Meta data transformer.</p>
* <p>Usage example:</p>
* <pre>
* <meta:value xmlns:meta="http://apache.org/lenya/meta/1.0/"
* element="title"
* ns="http://purl.org/dc/elements/1.1/"
* uuid="{$uuid}"
* lang="{$language}"
* default="default-title"
* i18n:attr="default" />
* </pre>
* <p>The attribute <em>default</em> is optional.</p>
*/
public class MetaDataTransformer extends AbstractSAXTransformer implements Disposable {
/**
* The namespace for the meta data is http://apache.org/lenya/meta/1.0
*/
static public final String NAMESPACE_URI = "http://apache.org/lenya/meta/1.0/";
/**
* The namespace prefix for this namespace.
*/
static public final String PREFIX = "meta";
/**
* The value element is getting the value for a specific ns and key. It is the only method
* implemented so far.
*/
static public final String VALUE_ELEMENT = "value";
/**
* ELEMENT_ATT - which meta data key do we want to look up
*/
static public final String ELEMENT_ATT = "element";
/**
* NS_ATT - in which namespace should we look
*/
static public final String NS_ATT = "ns";
/**
* UUID_ATT - for which uuid?
*/
static public final String UUID_ATT = "uuid";
/**
* LANG_ATT - in which language this is optional (when not found use publication default)
*/
static public final String LANG_ATT = "lang";
/**
* Use this attribute to provide a default value to be used if the document doesn't exist.
*/
static public final String DEFAULT_ATT = "default";
/** Helper for lenya document retrival */
protected String publicationId = null;
protected String area = null;
protected String language = null;
protected String uuid = null;
protected Publication pub;
private DocumentFactory factory;
/**
* Setup the MetaDataTransformer.
*/
public void setup(SourceResolver resolver, Map objectModel, String src, Parameters par)
throws ProcessingException, SAXException, IOException {
super.setup(resolver, objectModel, src, par);
this.publicationId = par.getParameter("pubid", null);
if (this.publicationId == null) {
throw new ProcessingException(
"The pubid is not set! Please set like e.g. <map:parameter name='pubid' value='{request-param:pubid}'/>");
}
this.area = par.getParameter("area", null);
if (this.area == null) {
throw new ProcessingException(
"The area is not set! Please set like e.g. <map:parameter name='area' value='{request-param:area}'/>");
}
Request request = ObjectModelHelper.getRequest(objectModel);
factory = DocumentUtil.getDocumentFactory(this.manager, request);
try {
pub = factory.getPublication(this.publicationId);
} catch (PublicationException e) {
throw new ProcessingException("Error geting publication id / area from page envelope",
e);
}
}
public void startElement(String uri, String name, String raw, Attributes attr)
throws SAXException {
if (NAMESPACE_URI.equals(uri)) {
if (VALUE_ELEMENT.equals(name)) {
String lang = null, uuid = null, ns = null, key = null, defaultValue = null;
for (int i = 0; i < attr.getLength(); i++) {
String localName = attr.getLocalName(i);
String value = attr.getValue(i);
if (ELEMENT_ATT.equals(localName))
key = value;
else if (NS_ATT.equals(localName))
ns = value;
else if (UUID_ATT.equals(localName))
uuid = value;
else if (LANG_ATT.equals(localName))
lang = value;
else if (DEFAULT_ATT.equals(localName))
defaultValue = value;
}// end for
if (uuid == null || ns == null || key == null)
throw new SAXException(
"Error by setting up the transformation. Please fix the calling code.");
if (lang == null)
lang = pub.getDefaultLanguage();
List returnValues = new ArrayList();
try {
Area areaObj = pub.getArea(this.area);
if (areaObj.contains(uuid, lang)) {
Document document = areaObj.getDocument(uuid, lang);
MetaData metaData = document.getMetaData(ns);
returnValues.addAll(Arrays.asList(metaData.getValues(key)));
} else if (defaultValue != null) {
returnValues.add(defaultValue);
} else {
String doc = this.publicationId + ":" + this.area + ":" + uuid + ":" + lang;
throw new SAXException("The document [" + doc
+ "] does not exist and no default value is provided.");
}
} catch (Exception e) {
throw new SAXException(e);
}
if (returnValues.size() > 1) {
for (Iterator i = returnValues.iterator(); i.hasNext();) {
String value = (String) i.next();
AttributesImpl attributes = new AttributesImpl();
attributes.addAttribute("", VALUE_ELEMENT, VALUE_ELEMENT, "CDATA", value);
attributes.addAttribute("", ELEMENT_ATT, ELEMENT_ATT, "CDATA", key);
this.contentHandler.startElement(ns, VALUE_ELEMENT, PREFIX + ":"
+ VALUE_ELEMENT, attributes);
this.contentHandler.endElement(ns, VALUE_ELEMENT, PREFIX + ":"
+ VALUE_ELEMENT);
}
} else if (returnValues.size() == 1) {
String value = (String) returnValues.get(0);
this.contentHandler.characters(value.toCharArray(), 0,
value.toCharArray().length);
}
} else {
String warn = "Could not find method for " + name + ". Ignoring.";
getLogger().warn(warn);
}
} else {
super.startElement(uri, name, raw, attr);
}
}
public void endElement(String uri, String name, String raw) throws SAXException {
if (!NAMESPACE_URI.equals(uri)) {
super.endElement(uri, name, raw);
}
}
public void recycle() {
super.recycle();
this.publicationId = null;
this.area = null;
this.language = null;
this.uuid = null;
this.pub = null;
this.factory = null;
}
}