/*
* 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 org.apache.commons.lang.StringUtils;
import org.apache.shindig.common.JsonSerializer;
import org.apache.shindig.config.ContainerConfig;
import org.apache.shindig.gadgets.GadgetContext;
import org.apache.shindig.gadgets.RenderingContext;
import org.apache.shindig.gadgets.config.ConfigContributor;
import org.apache.shindig.gadgets.features.FeatureRegistry;
import org.apache.shindig.gadgets.features.FeatureResource;
import javax.servlet.http.HttpServletRequest;
import java.util.Collection;
import java.util.Map;
import java.util.Set;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Maps;
import com.google.inject.Inject;
import com.google.inject.Singleton;
/**
* Provide processing logic for the JsServlet to serve the JavsScript as features request.
* This class will allow separation of flow and serving logic for easy customization.
*
*/
@Singleton
public class JsHandler {
protected final FeatureRegistry registry;
protected final ContainerConfig containerConfig;
protected final Map<String, ConfigContributor> configContributors;
@Inject
public JsHandler(FeatureRegistry registry, ContainerConfig containerConfig,
Map<String, ConfigContributor> configContributors) {
this.registry = registry;
this.containerConfig = containerConfig;
this.configContributors = configContributors;
}
/**
* Get the JavaScript content from the feature name aliases.
*
* @param req the HttpRequest object.
* @return JsHandlerResponse object that contains JavaScript data and cacheable flag.
*/
public JsHandlerResponse getJsContent(final HttpServletRequest req) {
// get the Set of features needed from request
Set<String> needed = getFeaturesNeeded(req);
// get the GadgetContext instance
GadgetContext ctx = getGadgetContext(req);
// get js data from feature resoources.
return getFeatureResourcesContent(req, ctx, needed);
}
/**
* Get the Set of feature names from the request.
*
* @param req the HttpServletRequest object.
* @return Set of names of needed JavaScript as feature aliases from the request.
*/
protected Set<String> getFeaturesNeeded(final HttpServletRequest req) {
// Use the last component as filename; prefix is ignored
String uri = req.getRequestURI();
// We only want the file name part. There will always be at least 1 slash
// (the server root), so this is always safe.
String resourceName = uri.substring(uri.lastIndexOf('/') + 1);
if (resourceName.endsWith(".js")) {
// Lop off the suffix for lookup purposes
resourceName = resourceName.substring(0, resourceName.length() - ".js".length());
}
Set<String> needed = ImmutableSet.copyOf(StringUtils.split(resourceName, ':'));
return needed;
}
/**
* Get the GadgetContext to be used when calling FeatureRegistry.getFeatureResources.
*
* @param req the HttpServletRequest object.
* @return GadgetContext instance.
*/
protected GadgetContext getGadgetContext(final HttpServletRequest req) {
String containerParam = req.getParameter("container");
String containerStr = req.getParameter("c");
final RenderingContext context = "1".equals(containerStr) ?
RenderingContext.CONTAINER : RenderingContext.GADGET;
final String container =
containerParam != null ? containerParam : ContainerConfig.DEFAULT_CONTAINER;
return new JsGadgetContext(context, container);
}
/**
* Get the content of the feature resources and push it to jsData.
*
* @param req The HttpServletRequest object.
* @param ctx GadgetContext object.
* @param needed Set of requested feature names.
* @return JsHandlerResponse object that contains JavaScript data and cacheable flag.
*/
protected JsHandlerResponse getFeatureResourcesContent(final HttpServletRequest req,
final GadgetContext ctx, Set<String> needed) {
StringBuilder jsData = new StringBuilder();
Collection<? extends FeatureResource> resources =
registry.getFeatureResources(ctx, needed, null);
String debugStr = req.getParameter("debug");
boolean debug = "1".equals(debugStr);
String container = ctx.getContainer();
boolean isProxyCacheable = true;
for (FeatureResource featureResource : resources) {
String content = debug ? featureResource.getDebugContent() : featureResource.getContent();
if (!featureResource.isExternal()) {
jsData.append(content);
} else {
// Support external/type=url feature serving through document.write()
jsData.append("document.write('<script src=\"").append(content).append("\"></script>')");
}
isProxyCacheable = isProxyCacheable && featureResource.isProxyCacheable();
jsData.append(";\n");
}
if (ctx.getRenderingContext() == RenderingContext.CONTAINER) {
// Append some container specific things
Map<String, Object> features = containerConfig.getMap(container, "gadgets.features");
Map<String, Object> config =
Maps.newHashMapWithExpectedSize(features == null ? 2 : features.size() + 2);
if (features != null) {
// Discard what we don't care about.
for (String name : registry.getFeatures(needed)) {
Object conf = features.get(name);
// Add from containerConfig
if (conf != null) {
config.put(name, conf);
}
ConfigContributor contributor = configContributors.get(name);
if (contributor != null) {
contributor.contribute(config, container, req.getHeader("Host"));
}
}
jsData.append("gadgets.config.init(").append(JsonSerializer.serialize(config)).append(");\n");
}
}
return new JsHandlerResponse(jsData, isProxyCacheable);
}
/**
* Define the response data from JsHandler.
*/
public static class JsHandlerResponse {
private final boolean isProxyCacheable;
private final StringBuilder jsData;
public JsHandlerResponse (StringBuilder jsData, boolean isProxyCacheable) {
this.jsData = jsData;
this.isProxyCacheable = isProxyCacheable;
}
public boolean isProxyCacheable() {
return isProxyCacheable;
}
public StringBuilder getJsData() {
return jsData;
}
}
/**
* GadgetContext for JsHandler called by FeatureRegistry when fetching the resources.
*/
protected static class JsGadgetContext extends GadgetContext {
private final RenderingContext renderingContext;
private final String container;
public JsGadgetContext(RenderingContext renderingContext, String container) {
this.renderingContext = renderingContext;
this.container = container;
}
@Override
public RenderingContext getRenderingContext() {
return renderingContext;
}
@Override
public String getContainer() {
return container;
}
}
}