org.apache.shindig.gadgets.js.ConfigInjectionProcessor Maven / Gradle / Ivy

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Renders gadgets, provides the gadget metadata service, and serves all javascript required by the OpenSocial specification.
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/*
 * 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.js;

import org.apache.shindig.common.JsonSerializer;
import org.apache.shindig.gadgets.GadgetContext;
import org.apache.shindig.gadgets.GadgetException;
import org.apache.shindig.gadgets.RenderingContext;
import org.apache.shindig.gadgets.config.ConfigProcessor;
import org.apache.shindig.gadgets.features.FeatureRegistry;
import org.apache.shindig.gadgets.features.FeatureRegistryProvider;
import org.apache.shindig.gadgets.uri.JsUriManager.JsUri;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import com.google.inject.Inject;

import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Set;

public class ConfigInjectionProcessor implements JsProcessor {
  @VisibleForTesting
  static final String GADGETS_FEATURES_KEY = "gadgets.features";
  @VisibleForTesting
  static final String CONFIG_FEATURE = "core.config.base";

  protected static final String CONFIG_GLOBAL_KEY_TPL = "window['___cfg']=%s;\n";
  protected static final String CONFIG_INIT_ID = "[config-injection]";
  protected static final String CONFIG_INIT_TPL = "gadgets.config.init(%s);\n";
  protected static final String CONFIG_INJECT_CODE =
      "window['___jsl'] = window['___jsl'] || {};" +
      "(window['___jsl']['ci'] = (window['___jsl']['ci'] || [])).push(%s);";

  private final FeatureRegistryProvider registryProvider;
  private final ConfigProcessor configProcessor;

  @Inject
  public ConfigInjectionProcessor(
      FeatureRegistryProvider registryProvider,
      ConfigProcessor configProcessor) {
    this.registryProvider = registryProvider;
    this.configProcessor = configProcessor;
  }

  public boolean process(JsRequest request, JsResponseBuilder builder) throws JsException {
    JsUri jsUri = request.getJsUri();
    GadgetContext ctx = new JsGadgetContext(jsUri);
    FeatureRegistry registry;
    try {
      registry = registryProvider.get(jsUri.getRepository());
    } catch (GadgetException e) {
      throw new JsException(e.getHttpStatusCode(), e.getMessage());
    }

    // Append gadgets.config initialization if not in standard gadget mode.
    if (ctx.getRenderingContext() != RenderingContext.GADGET) {
      List allReq = registry.getFeatures(jsUri.getLibs());
      Collection loaded = jsUri.getLoadedLibs();

      // Only inject config for features not already present and configured.
      List newReq = subtractCollection(allReq, loaded);

      Map config = configProcessor.getConfig(
          ctx.getContainer(), newReq, request.getHost(), null);
      if (!config.isEmpty()) {
        String configJson = JsonSerializer.serialize(config);
        if (allReq.contains(CONFIG_FEATURE) || loaded.contains(CONFIG_FEATURE)) {
          // config lib is present: pass it data
          injectBaseConfig(configJson, builder);
        } else {
          // config lib not available: use global variable
          injectGlobalConfig(configJson, builder);
        }
      }
    }
    return true;
  }
  
  protected void injectBaseConfig(String configJson, JsResponseBuilder builder) {
    builder.prependJs(String.format(CONFIG_INJECT_CODE, configJson), CONFIG_INIT_ID);
    builder.appendJs(String.format(CONFIG_INIT_TPL, configJson), CONFIG_INIT_ID);
  }

  protected void injectGlobalConfig(String configJson, JsResponseBuilder builder) {
    builder.appendJs(String.format(CONFIG_GLOBAL_KEY_TPL, configJson), CONFIG_INIT_ID);
  }

  private List subtractCollection(Collection root, Collection subtracted) {
    Set result = Sets.newHashSet(root);
    result.removeAll(subtracted);
    return Lists.newArrayList(result);
  }

}