/*
* 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.render;
import com.google.caja.lexer.CharProducer;
import com.google.caja.lexer.ExternalReference;
import com.google.caja.lexer.FetchedData;
import com.google.caja.lexer.InputSource;
import com.google.caja.lexer.JsLexer;
import com.google.caja.lexer.JsTokenQueue;
import com.google.caja.lexer.ParseException;
import com.google.caja.lexer.TokenConsumer;
import com.google.caja.parser.AncestorChain;
import com.google.caja.parser.ParseTreeNode;
import com.google.caja.parser.js.CajoledModule;
import com.google.caja.parser.js.Parser;
import com.google.caja.plugin.PipelineMaker;
import com.google.caja.plugin.PluginCompiler;
import com.google.caja.plugin.PluginMeta;
import com.google.caja.plugin.UriFetcher;
import com.google.caja.plugin.UriPolicy;
import com.google.caja.render.Concatenator;
import com.google.caja.render.JsMinimalPrinter;
import com.google.caja.render.JsPrettyPrinter;
import com.google.caja.reporting.BuildInfo;
import com.google.caja.reporting.MessageContext;
import com.google.caja.reporting.MessageQueue;
import com.google.caja.reporting.RenderContext;
import com.google.caja.reporting.SimpleMessageQueue;
import com.google.inject.Inject;
import org.apache.commons.io.IOUtils;
import org.apache.shindig.common.uri.Uri;
import org.apache.shindig.gadgets.Gadget;
import org.apache.shindig.gadgets.GadgetException;
import org.apache.shindig.gadgets.http.HttpRequest;
import org.apache.shindig.gadgets.http.HttpResponse;
import org.apache.shindig.gadgets.http.HttpResponseBuilder;
import org.apache.shindig.gadgets.http.RequestPipeline;
import org.apache.shindig.gadgets.rewrite.DomWalker;
import org.apache.shindig.gadgets.rewrite.ResponseRewriter;
import org.apache.shindig.gadgets.rewrite.RewriterUtils;
import org.apache.shindig.gadgets.rewrite.RewritingException;
import org.apache.shindig.gadgets.uri.ProxyUriManager;
import java.io.IOException;
import java.io.StringReader;
import java.util.Map;
import java.util.logging.Logger;
/**
* Rewriter that cajoles Javascript.
*
* @since 2.0.0
*/
public class CajaResponseRewriter implements ResponseRewriter {
private static final Logger LOG = Logger.getLogger(CajaResponseRewriter.class.getName());
private final RequestPipeline requestPipeline;
@Inject
public CajaResponseRewriter(RequestPipeline requestPipeline) {
this.requestPipeline = requestPipeline;
}
public void rewrite(HttpRequest req, HttpResponseBuilder resp) throws RewritingException {
if (!req.isCajaRequested()) { return; }
// Only accept Javascript for now
if (!RewriterUtils.isJavascript(req, resp)) {
resp.setContent("");
resp.setHttpStatusCode(HttpResponse.SC_BAD_REQUEST);
return;
}
boolean passed = false;
MessageQueue mq = new SimpleMessageQueue();
MessageContext mc = new MessageContext();
Uri contextUri = req.getUri();
InputSource is = new InputSource(contextUri.toJavaUri());
PluginMeta pluginMeta = new PluginMeta(
proxyFetcher(req, contextUri), proxyUriPolicy(req));
PluginCompiler compiler = new PluginCompiler(BuildInfo.getInstance(),
pluginMeta, mq);
compiler.setMessageContext(mc);
// Parse the javascript
try {
StringReader strReader = new StringReader(resp.getContent());
CharProducer cp = CharProducer.Factory.create(strReader, is);
JsTokenQueue tq = new JsTokenQueue(new JsLexer(cp), is);
ParseTreeNode input = new Parser(tq, mq).parse();
tq.expectEmpty();
compiler.addInput(AncestorChain.instance(input).node, contextUri.toJavaUri());
} catch (ParseException e) {
// Don't bother continuing.
resp.setContent("");
return;
}
try {
if (RewriterUtils.isJavascript(req, resp)) {
compiler.setGoals(
compiler.getGoals().without(PipelineMaker.HTML_SAFE_STATIC));
}
passed = compiler.run();
CajoledModule outputJs = passed ? compiler.getJavascript() : null;
StringBuilder jsOut = new StringBuilder();
TokenConsumer printer;
if ("1".equals(req.getParam("debug"))) {
printer = new JsPrettyPrinter(new Concatenator(jsOut));
} else {
printer = new JsMinimalPrinter(new Concatenator(jsOut));
}
RenderContext renderContext = new RenderContext(printer).withEmbeddable(true);
if (outputJs != null) {
outputJs.render(renderContext);
}
renderContext.getOut().noMoreTokens();
resp.setContent(jsOut.toString());
} finally {
if (!passed) {
resp.setContent("");
}
}
}
private UriPolicy proxyUriPolicy(HttpRequest request) {
final Uri contextUri = request.getUri();
final Gadget stubGadget = DomWalker.makeGadget(request);
return new UriPolicy() {
public String rewriteUri(ExternalReference ref, UriEffect effect,
LoaderType loader, Map<String, ?> hints) {
Uri resourceUri = Uri.fromJavaUri(ref.getUri());
if (contextUri != null) {
resourceUri = contextUri.resolve(resourceUri);
}
ProxyUriManager.ProxyUri proxyUri = new ProxyUriManager.ProxyUri(
stubGadget, resourceUri);
return proxyUri.getResource().toString();
}
};
}
private UriFetcher proxyFetcher(final HttpRequest req, final Uri contextUri) {
return new UriFetcher() {
public FetchedData fetch(ExternalReference ref, String mimeType) throws UriFetchException {
Uri resourceUri = Uri.fromJavaUri(ref.getUri());
if (contextUri != null) {
resourceUri = contextUri.resolve(resourceUri);
}
HttpRequest request = new HttpRequest(resourceUri)
.setContainer(req.getContainer())
.setGadget(req.getGadget());
try {
HttpResponse response = requestPipeline.execute(request);
byte[] responseBytes = IOUtils.toByteArray(response.getResponse());
return FetchedData.fromBytes(responseBytes, mimeType, response.getEncoding(),
new InputSource(ref.getUri()));
} catch (GadgetException e) {
LOG.info("Failed to retrieve: " + ref.toString());
return null;
} catch (IOException e) {
LOG.info("Failed to read: " + ref.toString());
return null;
}
}
};
}
}