/*
    * 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.myfaces.tobago.facelets;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.net.URL;
  
  /**
   * Provides facelets from the directory "META-INF/resources/" of any jar file in the classpath.
   * With the Servlet 3.0 specification this is no longer needed.
   * <p/>
   * To configure this ResourceResolver put this code into the web.xml file:
   * <pre>
   *  &lt;context-param&gt;
   *    &lt;param-name&gt;facelets.RESOURCE_RESOLVER&lt;/param-name&gt;
   *    &lt;param-value&gt;
   *        org.apache.myfaces.tobago.facelets.MetaInfResourcesClasspathResourceResolver
   *    &lt;/param-value&gt;
   *  &lt;/context-param&gt;
   * </pre>
   * <p/>
   */
  public class MetaInfResourcesClasspathResourceResolver extends DefaultResourceResolver {
  
    private static final Logger LOG = LoggerFactory.getLogger(MetaInfResourcesClasspathResourceResolver.class);
  
    public MetaInfResourcesClasspathResourceResolver() {
      if (LOG.isDebugEnabled()) {
        LOG.debug("MetaInfResourcesClasspathResourceResolver is configured to resolve resources.");
      }
    }
  
    public URL resolveUrl(String path) {
      URL url = super.resolveUrl(path);
      if (LOG.isDebugEnabled()) {
        LOG.debug("default   url='" + url + "'");
      }
      if (url == null) {
        if (path.startsWith("/")) {
          path = path.substring(1);
        }
        path = "META-INF/resources/" + path;
  
        url = Thread.currentThread().getContextClassLoader().getResource(path);
        if (LOG.isDebugEnabled()) {
          LOG.debug("classpath url='" + url + "'");
        }
      }
      return url;
    }
  }