/*
* 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.shindig.gadgets.servlet;
import com.google.caja.lexer.ExternalReference;
import com.google.caja.lexer.InputSource;
import com.google.caja.lexer.escaping.Escaping;
import com.google.caja.opensocial.DefaultGadgetRewriter;
import com.google.caja.opensocial.GadgetRewriteException;
import com.google.caja.opensocial.UriCallback;
import com.google.caja.opensocial.UriCallbackException;
import com.google.caja.parser.html.Nodes;
import com.google.caja.render.Concatenator;
import com.google.caja.reporting.BuildInfo;
import com.google.caja.reporting.Message;
import com.google.caja.reporting.MessageContext;
import com.google.caja.reporting.MessageLevel;
import com.google.caja.reporting.MessageQueue;
import com.google.caja.reporting.RenderContext;
import com.google.caja.reporting.SimpleMessageQueue;
import com.google.caja.reporting.SnippetProducer;
import com.google.caja.util.Pair;
import com.google.common.collect.Maps;
import com.google.inject.Inject;
import org.apache.commons.lang.StringUtils;
import org.apache.shindig.common.cache.Cache;
import org.apache.shindig.common.cache.CacheProvider;
import org.apache.shindig.common.util.HashUtil;
import org.apache.shindig.gadgets.Gadget;
import org.apache.shindig.gadgets.parse.HtmlSerialization;
import org.apache.shindig.gadgets.parse.HtmlSerializer;
import org.apache.shindig.gadgets.rewrite.MutableContent;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringReader;
import java.io.StringWriter;
import java.net.URI;
import java.util.Map;
import java.util.logging.Logger;
public class CajaContentRewriter implements org.apache.shindig.gadgets.rewrite.GadgetRewriter {
public static final String CAJOLED_DOCUMENTS = "cajoledDocuments";
private final Logger logger = Logger.getLogger(CajaContentRewriter.class.getName());
private Cache<String, Element> cajoledCache;
@Inject
public void setCacheProvider(CacheProvider cacheProvider) {
cajoledCache = cacheProvider.createCache(CAJOLED_DOCUMENTS);
logger.info("Cajoled cache created" + cajoledCache);
}
public void rewrite(Gadget gadget, MutableContent content) {
if (gadget.getSpec().getModulePrefs().getFeatures().containsKey("caja") ||
"1".equals(gadget.getContext().getParameter("caja"))) {
final URI retrievedUri = gadget.getContext().getUrl().toJavaUri();
UriCallback cb = new UriCallback() {
public Reader retrieve(ExternalReference externalReference, String string)
throws UriCallbackException {
logger.info("Retrieving " + externalReference.toString());
Reader in = null;
try {
URI resourceUri = retrievedUri.resolve(externalReference.getUri());
in = new InputStreamReader(
resourceUri.toURL().openConnection().getInputStream(), "UTF-8");
char[] buf = new char[4096];
StringBuilder sb = new StringBuilder();
for (int n; (n = in.read(buf)) > 0;) {
sb.append(buf, 0, n);
}
return new StringReader(sb.toString());
} catch (java.net.MalformedURLException ex) {
throw new UriCallbackException(externalReference, ex);
} catch (IOException ex) {
throw new UriCallbackException(externalReference, ex);
} finally {
try {
in.close();
} catch (IOException e) {
// Not sure what else we can do here
throw new RuntimeException(e);
}
}
}
public URI rewrite(ExternalReference externalReference, String mimeType) {
URI uri = externalReference.getUri();
if (uri.getScheme().equalsIgnoreCase("https") ||
uri.getScheme().equalsIgnoreCase("http")) {
return retrievedUri.resolve(uri);
} else if ("javascript".equalsIgnoreCase(uri.getScheme())) {
// Commonly used javascript url for links with onclick handlers
return uri.toString().equals("javascript:void(0)") ? uri : null;
} else {
return null;
}
}
};
String key = HashUtil.rawChecksum(content.getContent().getBytes());
Document doc = content.getDocument();
Node root = doc.createDocumentFragment();
root.appendChild(doc.getDocumentElement());
Element cajoledOutput = null;
if (null != cajoledCache) {
cajoledOutput = cajoledCache.getElement(key);
if (null != cajoledOutput) {
createContainerFor(doc, doc.adoptNode(cajoledOutput));
content.documentChanged();
HtmlSerialization.attach(doc, new CajaHtmlSerializer(), null);
return;
}
}
MessageQueue mq = new SimpleMessageQueue();
BuildInfo bi = BuildInfo.getInstance();
DefaultGadgetRewriter rw = new DefaultGadgetRewriter(bi, mq);
InputSource is = new InputSource(retrievedUri);
boolean safe = false;
try {
Pair<Node, Element> htmlAndJs = rw.rewriteContent(retrievedUri, root, cb);
Node html = htmlAndJs.a;
Element script = htmlAndJs.b;
cajoledOutput = doc.createElement("div");
cajoledOutput.setAttribute("id", "cajoled-output");
cajoledOutput.setAttribute("classes", "g___");
cajoledOutput.setAttribute("style", "position: relative;");
cajoledOutput.appendChild(doc.adoptNode(html));
cajoledOutput.appendChild(tameCajaClientApi(doc));
cajoledOutput.appendChild(doc.adoptNode(script));
if (cajoledCache != null) {
cajoledCache.addElement(key, cajoledOutput);
}
createContainerFor(doc, cajoledOutput);
content.documentChanged();
safe = true;
HtmlSerialization.attach(doc, new CajaHtmlSerializer(), null);
} catch (GadgetRewriteException e) {
// There were cajoling errors
// Content is only used to produce useful snippets with error messages
createContainerFor(doc, formatErrors(doc, is, content.getContent(), mq));
logException(e, mq);
safe = true;
} finally {
if (!safe) {
// Fail safe
content.setContent("");
}
}
}
}
private void createContainerFor(Document doc, Node el) {
Element docEl = doc.createElement("html");
Element head = doc.createElement("head");
Element body = doc.createElement("body");
doc.appendChild(docEl);
docEl.appendChild(head);
docEl.appendChild(body);
body.appendChild(el);
}
private Element formatErrors(Document doc, InputSource is,
CharSequence orig, MessageQueue mq) {
MessageContext mc = new MessageContext();
Map<InputSource, CharSequence> originalSrc = Maps.newHashMap();
originalSrc.put(is, orig);
mc.addInputSource(is);
SnippetProducer sp = new SnippetProducer(originalSrc, mc);
StringBuilder messageText = new StringBuilder();
for (Message msg : mq.getMessages()) {
// Ignore LINT messages
if (MessageLevel.LINT.compareTo(msg.getMessageLevel()) <= 0) {
String snippet = sp.getSnippet(msg);
messageText.append(msg.getMessageLevel().name())
.append(' ')
.append(html(msg.format(mc)));
if (!StringUtils.isEmpty(snippet)) {
messageText.append('\n').append(snippet);
}
}
}
Element errElement = doc.createElement("pre");
errElement.appendChild(doc.createTextNode(messageText.toString()));
return errElement;
}
private static String html(CharSequence s) {
StringBuilder sb = new StringBuilder();
Escaping.escapeXml(s, false, sb);
return sb.toString();
}
private Element tameCajaClientApi(Document doc) {
Element scriptElement = doc.createElement("script");
scriptElement.setAttribute("type", "text/javascript");
scriptElement.appendChild(doc.createTextNode("caja___.enable()"));
return scriptElement;
}
private void logException(Exception cause, MessageQueue mq) {
StringBuilder errbuilder = new StringBuilder();
MessageContext mc = new MessageContext();
if (cause != null) {
errbuilder.append(cause).append('\n');
}
for (Message m : mq.getMessages()) {
errbuilder.append(m.format(mc)).append('\n');
}
logger.info("Unable to cajole gadget: " + errbuilder);
}
private static class CajaHtmlSerializer implements HtmlSerializer {
public String serialize(Document doc) {
StringWriter sw = HtmlSerialization.createWriter(doc);
return Nodes.render(doc, new RenderContext(new Concatenator(sw, null)).asXml());
}
}
}