/*
* 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.cms.cocoon.transformation;
import java.io.IOException;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.Stack;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.parameters.ParameterException;
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.ac.AccessControlException;
import org.apache.lenya.cms.linking.LinkRewriter;
import org.apache.lenya.cms.publication.Publication;
import org.apache.lenya.cms.publication.URLInformation;
import org.apache.lenya.util.ServletHelper;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
/**
* <p>
* This transformer processes all links which are configured using
* <code><transform/></code> elements.
* </p>
* <p>
* If the link rewriter returns <code>null</code> for a link, an attribute can
* be added to the corresponding element, with an optional message of the form
* "Broken link: ...".
* </p>
* <code><pre>
* <map:transformer ... >
* <transform namespace="http://www.w3.org/1999/xhtml" element="a" attribute="href"/>
* <transform namespace="..." ... />
* <markBrokenLinks attribute="..." value="..." messageAttribute="..."/>
* </map:transformer>
* </pre></code>
* <p>
* The reference URL can optionally be passed using the <em>url</em>
* parameter.
* </p>
*/
public abstract class AbstractLinkTransformer extends AbstractSAXTransformer {
private String area;
protected static final String PARAM_URL = "url";
public void setup(SourceResolver resolver, Map objectModel, String src, Parameters params)
throws ProcessingException, SAXException, IOException {
super.setup(resolver, objectModel, src, params);
String webappUrl = getWebappUrl(params, objectModel);
URLInformation url = new URLInformation(webappUrl);
this.area = url.getArea();
}
/**
* @param params
* @param objectModel
* @return The web application URL which was passed using the <em>url</em>
* parameter or the web application URL the transformer was called on,
* respectively.
* @throws ProcessingException
*/
protected String getWebappUrl(Parameters params, Map objectModel) throws ProcessingException {
String webappUrl;
if (params.isParameter(PARAM_URL)) {
try {
webappUrl = params.getParameter(PARAM_URL);
} catch (ParameterException e) {
throw new ProcessingException(e);
}
} else {
Request request = ObjectModelHelper.getRequest(objectModel);
webappUrl = ServletHelper.getWebappURI(request);
}
return webappUrl;
}
/**
* Set of supported local names for quick pre-checks.
*/
private Set localNames = new HashSet();
private boolean markBrokenLinks;
private String brokenLinkAttribute;
private String brokenLinkValue;
private String brokenLinkMessageAttribute;
public void configure(Configuration config) throws ConfigurationException {
super.configure(config);
Configuration[] transformConfigs = config.getChildren("transform");
for (int i = 0; i < transformConfigs.length; i++) {
String namespace = transformConfigs[i].getAttribute("namespace");
String element = transformConfigs[i].getAttribute("element");
String attribute = transformConfigs[i].getAttribute("attribute");
AttributeConfiguration attrConfig = new AttributeConfiguration(namespace, element,
attribute);
String key = getCacheKey(namespace, element);
Set configs = (Set) this.namespaceLocalname2configSet.get(key);
if (configs == null) {
configs = new HashSet();
this.localNames.add(element);
this.namespaceLocalname2configSet.put(key, configs);
}
configs.add(attrConfig);
}
Configuration brokenLinksConfig = config.getChild("markBrokenLinks", false);
if (brokenLinksConfig != null) {
this.brokenLinkAttribute = brokenLinksConfig.getAttribute("attribute");
this.brokenLinkValue = brokenLinksConfig.getAttribute("value");
String messageAttr = brokenLinksConfig.getAttribute("messageAttribute", null);
if (messageAttr != null) {
this.brokenLinkMessageAttribute = messageAttr;
}
this.markBrokenLinks = true;
} else {
this.markBrokenLinks = false;
}
}
/**
* Declaration of an attribute which should be transformed.
*/
public static class AttributeConfiguration {
protected final String element;
protected final String namespace;
protected final String attribute;
/**
* @param namespace The namespace of the element.
* @param element The local name of the element.
* @param attribute The name of the attribute to transform.
*/
public AttributeConfiguration(String namespace, String element, String attribute) {
this.namespace = namespace;
this.element = element;
this.attribute = attribute;
}
/**
* @param uri The namespace URI.
* @param name The local name.
* @param attrs The attributes.
* @return If this configuration matches the parameters.
*/
public boolean matches(String uri, String name, Attributes attrs) {
return this.namespace.equals(uri) && this.element.equals(name)
&& attrs.getValue(this.attribute) != null;
}
}
/**
* @param namespace The namespace URI.
* @param localName The local name.
* @param attrs The attributes.
* @return A set of {@link AttributeConfiguration} objects.
*/
protected Set getMatchingConfigurations(String namespace, String localName, Attributes attrs) {
// pre-check for performance reasons
if (!existsMatchingConfiguration(namespace, localName)) {
return Collections.EMPTY_SET;
}
String key = getCacheKey(namespace, localName);
// don't initialize yet for performance reasons
Set configs = null;
Set allConfigs = (Set) this.namespaceLocalname2configSet.get(key);
for (Iterator i = allConfigs.iterator(); i.hasNext();) {
AttributeConfiguration config = (AttributeConfiguration) i.next();
if (config.matches(namespace, localName, attrs)) {
if (configs == null) {
configs = new HashSet();
}
configs.add(config);
}
}
if (configs == null) {
configs = Collections.EMPTY_SET;
}
return configs;
}
/**
* Cache to improve performance.
*/
private Map namespaceLocalname2configSet = new HashMap();
protected boolean existsMatchingConfiguration(String namespace, String localName) {
// quick pre-check
if (!this.localNames.contains(localName)) {
return false;
}
// more expensive check
String key = getCacheKey(namespace, localName);
return this.namespaceLocalname2configSet.containsKey(key);
}
protected String getCacheKey(String namespace, String localName) {
return namespace + " " + localName;
}
protected String indent = "";
protected boolean ignoreLinkElement = false;
private Stack ignoreLinkElementStack = new Stack();
protected boolean useIgnore = false;
/**
* @see org.xml.sax.ContentHandler#startElement(java.lang.String,
* java.lang.String, java.lang.String, org.xml.sax.Attributes)
*/
public void startElement(String uri, String name, String qname, Attributes attrs)
throws SAXException {
if (getLogger().isDebugEnabled()) {
getLogger().debug(
this.indent + "<" + qname + "> (ignoreAElement = " + this.ignoreLinkElement
+ ")");
this.indent += " ";
}
Set configs = getMatchingConfigurations(uri, name, attrs);
AttributesImpl newAttrs = null;
if (!configs.isEmpty()) {
newAttrs = new AttributesImpl(attrs);
this.ignoreLinkElement = false;
for (Iterator i = configs.iterator(); i.hasNext();) {
AttributeConfiguration config = (AttributeConfiguration) i.next();
String linkUrl = newAttrs.getValue(config.attribute);
try {
if (getLogger().isDebugEnabled()) {
getLogger().debug(this.indent + "link URL: [" + linkUrl + "]");
}
handleLink(linkUrl, config, newAttrs);
} catch (final Exception e) {
getLogger().error("startElement failed: ", e);
throw new SAXException(e);
}
}
}
if (getLogger().isDebugEnabled()) {
getLogger().debug(this.indent + "ignoreAElement: " + this.ignoreLinkElement);
}
// use existsMatching to match up with endElement
if (existsMatchingConfiguration(uri, name) && this.useIgnore) {
if (this.ignoreLinkElement) {
this.ignoreLinkElementStack.push(Boolean.TRUE);
return;
} else {
this.ignoreLinkElementStack.push(Boolean.FALSE);
}
}
if (newAttrs != null) {
attrs = newAttrs;
}
super.startElement(uri, name, qname, attrs);
if (getLogger().isDebugEnabled()) {
getLogger().debug(this.indent + "<" + qname + "> sent");
}
}
/**
* Handle a link in the source SAX stream.
* @param linkUrl The link URL.
* @param config The attribute configuration which matched the link.
* @param newAttrs The new attributes which will be added to the result
* element.
* @throws Exception if an error occurs.
*/
protected void handleLink(String linkUrl, AttributeConfiguration config, AttributesImpl newAttrs)
throws Exception {
if (getLinkRewriter().matches(linkUrl)) {
String rewrittenUrl = getLinkRewriter().rewrite(linkUrl);
if (rewrittenUrl != null) {
setAttribute(newAttrs, config.attribute, rewrittenUrl);
} else {
if (this.area != null && this.area.equals(Publication.LIVE_AREA)) {
this.ignoreLinkElement = true;
} else {
markBrokenLink(newAttrs, config.attribute, linkUrl);
}
}
}
}
/**
* @see org.xml.sax.ContentHandler#endElement(java.lang.String,
* java.lang.String, java.lang.String)
*/
public void endElement(String uri, String name, String qname) throws SAXException {
if (getLogger().isDebugEnabled()) {
this.indent = this.indent.substring(2);
getLogger().debug(this.indent + "</" + qname + ">");
}
if (existsMatchingConfiguration(uri, name) && this.useIgnore) {
if (((Boolean) this.ignoreLinkElementStack.pop()).booleanValue()) {
this.ignoreLinkElement = false;
return;
}
}
if (getLogger().isDebugEnabled()) {
getLogger().debug(this.indent + "</" + qname + "> sent");
}
super.endElement(uri, name, qname);
}
/**
* Sets the value of a certain attribute.
*
* @param attr The attributes.
* @param name The attribute name.
* @param value The value.
* @throws IllegalArgumentException if the href attribute is not contained
* in this attributes.
*/
protected void setAttribute(AttributesImpl attr, String name, String value) {
int position = attr.getIndex(name);
if (position == -1) {
throw new IllegalArgumentException("The attribute [" + name + "] is not available!");
}
attr.setValue(position, value);
}
/**
* @return The link rewriter used by this transformer.
*/
protected abstract LinkRewriter getLinkRewriter();
/**
* Marks a link element as broken and removes the attribute which contained
* the URL.
* @param newAttrs The new attributes.
* @param attrName The attribute name containing the URL which could not be
* rewritten.
* @param brokenLinkUri The broken link URI.
* @throws AccessControlException when something went wrong.
*/
protected void markBrokenLink(AttributesImpl newAttrs, String attrName, String brokenLinkUri)
throws AccessControlException {
if (this.markBrokenLinks) {
if (newAttrs.getIndex(this.brokenLinkAttribute) > -1) {
newAttrs.removeAttribute(newAttrs.getIndex(this.brokenLinkAttribute));
}
if (newAttrs.getIndex(attrName) > -1) {
newAttrs.setAttribute(newAttrs.getIndex(attrName), "", attrName, attrName, "CDATA",
"");
}
String msgAttr = this.brokenLinkMessageAttribute;
if (msgAttr != null) {
int index = newAttrs.getIndex(msgAttr);
if (index > -1) {
newAttrs.removeAttribute(index);
}
String msg = "Broken link: " + brokenLinkUri;
newAttrs.addAttribute("", msgAttr, msgAttr, "CDATA", msg);
}
newAttrs.addAttribute("", this.brokenLinkAttribute, this.brokenLinkAttribute, "CDATA",
this.brokenLinkValue);
}
}
public void recycle() {
super.recycle();
this.area = null;
this.ignoreLinkElementStack.clear();
}
}