/*******************************************************************************
* Copyright (c) 2006, 2007 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.help.internal.dynamic;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.ParserConfigurationException;
import org.eclipse.help.HelpSystem;
import org.eclipse.help.internal.HelpPlugin;
import org.eclipse.help.internal.UAElement;
import org.eclipse.help.internal.extension.ContentExtension;
import org.eclipse.help.internal.extension.ContentExtensionManager;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.xml.sax.SAXException;
/*
* Resolves the content to use for extensions. For anchors, these are the
* nodes that will be inserted at the anchor. For replaces, these are the
* nodes that will replace the original nodes.
*/
public class ExtensionResolver {
private static final String ELEMENT_BODY = "body"; //$NON-NLS-1$
private static final String ATTRIBUTE_ID = "id"; //$NON-NLS-1$
private DocumentProcessor processor;
private DocumentReader reader;
private String locale;
private ContentExtensionManager manager;
/*
* Creates the resolver. The processor is needed to process the extension
* content, and locale because we're pulling in content from other documents.
*/
public ExtensionResolver(DocumentProcessor processor, DocumentReader reader, String locale) {
this.processor = processor;
this.reader = reader;
this.locale = locale;
}
/*
* Resolves the given path into nodes to be inserted.
*/
public Node[] resolveExtension(String path, int type) {
if (manager == null) {
manager = HelpPlugin.getContentExtensionManager();
}
ContentExtension[] extensions = manager.getExtensions(path, type, locale);
List list = new ArrayList();
for (int i=0;i<extensions.length;++i) {
String content = extensions[i].getContent();
try {
Node[] nodes = getContent(content);
for (int j=0;j<nodes.length;++j) {
list.add(nodes[j]);
}
}
catch (Throwable t) {
// ignore invalid extensions
}
}
return (Node[])list.toArray(new Node[list.size()]);
}
/*
* Resolves the given content path (the content to insert/replace with) into
* nodes.
*/
private Node[] getContent(String content) throws IOException, SAXException, ParserConfigurationException {
String bundleId = null;
String relativePath = null;
String nodeId = null;
int bundleStart = 0;
// legacy; can omit leading slash
if (content.charAt(0) == '/') {
bundleStart = 1;
}
int bundleEnd = content.indexOf('/', bundleStart + 1);
if (bundleEnd > bundleStart) {
bundleId = content.substring(bundleStart, bundleEnd);
int pathStart = bundleEnd + 1;
int pathEnd = content.indexOf('#', pathStart + 1);
if (pathEnd == -1) {
// legacy; slash can be used instead of '#'
int lastSlash = content.lastIndexOf('/');
int secondLastSlash = content.lastIndexOf('/', lastSlash - 1);
if (secondLastSlash != -1 && lastSlash > secondLastSlash) {
String secondLastToken = content.substring(secondLastSlash + 1, lastSlash);
if (secondLastToken.indexOf('.') != -1) {
pathEnd = lastSlash;
}
else {
pathEnd = content.length();
}
}
else {
pathEnd = content.length();
}
}
relativePath = content.substring(pathStart, pathEnd);
if (pathEnd < content.length()) {
nodeId = content.substring(pathEnd + 1);
}
}
if (bundleId != null && relativePath != null) {
return getContent(bundleId, relativePath, nodeId);
}
return null;
}
/*
* Resolves the given parsed content fragments into nodes.
*/
private Node[] getContent(String bundleId, String relativePath, String nodeId) throws IOException, SAXException, ParserConfigurationException {
String href = '/' + bundleId + '/' + relativePath;
InputStream in = HelpSystem.getHelpContent(href, locale);
try {
if (nodeId != null) {
Element element = findElement(in, nodeId);
processor.process(new UAElement(element), href);
return new Node[] { element };
}
Element body = findBody(in);
List children = new ArrayList();
Node node = body.getFirstChild();
while (node != null) {
if (node.getNodeType() == Node.ELEMENT_NODE) {
processor.process(new UAElement((Element)node), href);
}
children.add(node);
node = node.getNextSibling();
}
return (Node[])children.toArray(new Node[children.size()]);
}
finally {
try {
in.close();
}
catch (IOException e) {}
}
}
/*
* Finds and returns the element with the given elementId from the XML input
* stream, or null if not found.
*/
private Element findElement(InputStream in, String elementId) throws IOException, SAXException, ParserConfigurationException {
return findElement(reader.read(in).element, elementId);
}
/*
* Finds and returns the element with the given elementId from the under the
* given element, or null if not found.
*/
private Element findElement(Element element, String elementId) {
String id = element.getAttribute(ATTRIBUTE_ID);
if (id != null && id.equals(elementId)) {
return element;
}
Node node = element.getFirstChild();
while (node != null) {
if (node.getNodeType() == Node.ELEMENT_NODE) {
element = findElement((Element)node, elementId);
if (element != null) {
return element;
}
}
node = node.getNextSibling();
}
return null;
}
/*
* Finds and returns the body node in the given XML input.
*/
private Element findBody(InputStream in) throws IOException, SAXException, ParserConfigurationException {
return findBody(reader.read(in).element);
}
/*
* Finds and returns the body node under the given node.
*/
private Element findBody(Element element) {
if (ELEMENT_BODY.equals(element.getNodeName())) {
return element;
}
Node node = element.getFirstChild();
while (node != null) {
if (node.getNodeType() == Node.ELEMENT_NODE) {
Element body = findBody((Element)node);
if (body != null) {
return body;
}
}
node = node.getNextSibling();
}
return null;
}
}