/* 
    P/P   *  Method: net.sourceforge.pebble.web.action.FeedAction__static_init
          */
     1  /*
     2   * Copyright (c) 2003-2006, Simon Brown
     3   * All rights reserved.
     4   *
     5   * Redistribution and use in source and binary forms, with or without
     6   * modification, are permitted provided that the following conditions are met:
     7   *
     8   *   - Redistributions of source code must retain the above copyright
     9   *     notice, this list of conditions and the following disclaimer.
    10   *
    11   *   - Redistributions in binary form must reproduce the above copyright
    12   *     notice, this list of conditions and the following disclaimer in
    13   *     the documentation and/or other materials provided with the
    14   *     distribution.
    15   *
    16   *   - Neither the name of Pebble nor the names of its contributors may
    17   *     be used to endorse or promote products derived from this software
    18   *     without specific prior written permission.
    19   *
    20   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    21   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    22   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    23   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
    24   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
    25   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
    26   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    27   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
    28   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    29   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    30   * POSSIBILITY OF SUCH DAMAGE.
    31   */
    32  package net.sourceforge.pebble.web.action;
    33  
    34  import net.sourceforge.pebble.Constants;
    35  import net.sourceforge.pebble.comparator.BlogEntryComparator;
    36  import net.sourceforge.pebble.domain.*;
    37  import net.sourceforge.pebble.web.view.NotModifiedView;
    38  import net.sourceforge.pebble.web.view.View;
    39  import net.sourceforge.pebble.web.view.impl.AtomView;
    40  import net.sourceforge.pebble.web.view.impl.RdfView;
    41  import net.sourceforge.pebble.web.view.impl.RssView;
    42  
         /* 
    P/P   *  Method: void net.sourceforge.pebble.web.action.FeedAction()
          */
    43  import javax.servlet.ServletException;
    44  import javax.servlet.http.HttpServletRequest;
    45  import javax.servlet.http.HttpServletResponse;
    46  import java.text.SimpleDateFormat;
    47  import java.util.*;
    48  
    49  /**
    50   * Gets the RSS for a blog.
    51   *
    52   * @author    Simon Brown
    53   */
    54  public class FeedAction extends Action {
    55  
    56    /**
    57     * Peforms the processing associated with this action.
    58     *
    59     * @param request  the HttpServletRequest instance
    60     * @param response the HttpServletResponse instance
    61     * @return the name of the next view
    62     */
    63    public View process(HttpServletRequest request, HttpServletResponse response) throws ServletException {
             /* 
    P/P       *  Method: View process(HttpServletRequest, HttpServletResponse)
              * 
              *  Preconditions:
              *    request != null
              *    response != null
              *    this.model != null
              *    this.model.data != null
              * 
              *  Presumptions:
              *    java.util.HashMap:get(...)@63 != null
              *    java.util.Iterator:next(...)@116 != null
              *    init'ed(java.util.Locale.ENGLISH)
              *    net.sourceforge.pebble.domain.AbstractBlog:getLastModified(...)@79 != null
              *    net.sourceforge.pebble.domain.AbstractBlog:getRecentBlogEntries(...)@110 != null
              *    ...
              * 
              *  Postconditions:
              *    return_value in Addr_Set{&new NotModifiedView(process#5),&new NotModifiedView(process#7),&new AtomView(process#10),&new RdfView(process#11),&new RssView(process#12)}
              *    new AtomView(process#10) num objects <= 1
              *    new NotModifiedView(process#5) num objects <= 1
              *    new NotModifiedView(process#7) num objects <= 1
              *    new RdfView(process#11) num objects <= 1
              *    new RssView(process#12) num objects <= 1
              * 
              *  Test Vectors:
              *    java.lang.String:equals(...)@83: {0}, {1}
              *    java.lang.String:equals(...)@85: {0}, {1}
              *    java.lang.String:equalsIgnoreCase(...)@135: {0}, {1}
              *    java.lang.String:equalsIgnoreCase(...)@137: {0}, {1}
              *    java.lang.String:equalsIgnoreCase(...)@73: {0}, {1}
              *    java.util.Iterator:hasNext(...)@115: {1}, {0}
              *    javax.servlet.http.HttpServletRequest:getHeader(...)@70: Addr_Set{null}, Inverse{null}
              *    javax.servlet.http.HttpServletRequest:getHeader(...)@71: Addr_Set{null}, Inverse{null}
              *    javax.servlet.http.HttpServletRequest:getParameter(...)@186: Addr_Set{null}, Inverse{null}
              *    javax.servlet.http.HttpServletRequest:getParameter(...)@65: Addr_Set{null}, Inverse{null}
              *    ...
              */
    64      AbstractBlog blog = (AbstractBlog)getModel().get(Constants.BLOG_KEY);
    65      String flavor = request.getParameter("flavor");
    66  
    67      SimpleDateFormat httpFormat = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss z");
    68      httpFormat.setTimeZone(TimeZone.getTimeZone("GMT"));
    69  
    70      String ifModifiedSince = request.getHeader("If-Modified-Since");
    71      String ifNoneMatch = request.getHeader("If-None-Match");
    72  
    73      if (flavor != null && flavor.equalsIgnoreCase("atom")) {
    74        response.setContentType("application/atom+xml; charset=" + blog.getCharacterEncoding());
    75      } else {
    76        response.setContentType("application/xml; charset=" + blog.getCharacterEncoding());
    77      }
    78  
    79      Date lastModified = blog.getLastModified();
    80      response.setDateHeader("Last-Modified", lastModified.getTime());
    81      response.setHeader("ETag", "\"" + httpFormat.format(lastModified) + "\"");
    82  
    83      if (ifModifiedSince != null && ifModifiedSince.equals(httpFormat.format(lastModified))) {
    84        return new NotModifiedView();
    85      } else if (ifNoneMatch != null && ifNoneMatch.equals("\"" + httpFormat.format(lastModified) + "\"")) {
    86        return new NotModifiedView();
    87      } else {
    88        List blogEntries;
    89        String s = request.getParameter("includeAggregatedContent");
    90        boolean includeAggregatedContent = (s == null || s.equalsIgnoreCase("true"));
    91  
    92        if (blog instanceof Blog) {
    93          Tag tag = getTag((Blog)blog, request);
    94          Category category = getCategory((Blog)blog, request);
    95          String author = getAuthor(request);
    96  
    97          if (tag != null) {
    98            blogEntries = ((Blog)blog).getRecentPublishedBlogEntries(tag);
    99            getModel().put("tag", tag);
   100          } else if (category != null) {
   101            blogEntries = ((Blog)blog).getRecentPublishedBlogEntries(category);
   102            getModel().put("category", category);
   103          } else if (author != null) {
   104            blogEntries = ((Blog)blog).getRecentPublishedBlogEntries(author);
   105            getModel().put("author", author);
   106          } else {
   107            blogEntries = ((Blog)blog).getRecentPublishedBlogEntries();
   108          }
   109        } else {
   110          blogEntries = blog.getRecentBlogEntries();
   111        }
   112  
   113        List blogEntriesForFeed = new ArrayList();
   114        Iterator it = blogEntries.iterator();
   115        while (it.hasNext()) {
   116          BlogEntry entry = (BlogEntry)it.next();
   117  
   118          if (!includeAggregatedContent && entry.isAggregated()) {
   119            continue;
   120          } else {
   121            blogEntriesForFeed.add(entry);
   122          }
   123        }
   124  
   125        Collections.sort(blogEntriesForFeed, new BlogEntryComparator());
   126  
   127        getModel().put(Constants.BLOG_ENTRIES, blogEntriesForFeed);
   128  
   129        // set the locale of this feed request to be English
   130        javax.servlet.jsp.jstl.core.Config.set(
   131            request,
   132            javax.servlet.jsp.jstl.core.Config.FMT_LOCALE,
   133            Locale.ENGLISH);
   134  
   135        if (flavor != null && flavor.equalsIgnoreCase("atom")) {
   136          return new AtomView();
   137        } else if (flavor != null && flavor.equalsIgnoreCase("rdf")) {
   138          return new RdfView();
   139        } else {
   140          return new RssView();
   141        }
   142      }
   143    }
   144  
   145    /**
   146     * Helper method to find a named tag from a request parameter.
   147     *
   148     * @param blog      the blog for which the feed is for
   149     * @param request   the HTTP request containing the tag parameter
   150     * @return  a Tag instance, or null if the tag isn't
   151     *          specified or can't be found
   152     */
   153    private Tag getTag(Blog blog, HttpServletRequest request) {
             /* 
    P/P       *  Method: Tag getTag(Blog, HttpServletRequest)
              * 
              *  Preconditions:
              *    request != null
              * 
              *  Postconditions:
              *    return_value == One-of{&new Tag(getTag#1), null}
              *    return_value in Addr_Set{null,&new Tag(getTag#1)}
              *    new Tag(getTag#1) num objects <= 1
              * 
              *  Test Vectors:
              *    javax.servlet.http.HttpServletRequest:getParameter(...)@154: Addr_Set{null}, Inverse{null}
              */
   154      String tag = request.getParameter("tag");
   155      if (tag != null) {
   156        return new Tag(tag, blog);
   157      } else {
   158        return null;
   159      }
   160    }
   161  
   162    /**
   163     * Helper method to find a named category from a request parameter.
   164     *
   165     * @param blog      the blog for which the feed is for
   166     * @param request   the HTTP request containing the category parameter
   167     * @return  a Category instance, or null if the category isn't
   168     *          specified or can't be found
   169     */
   170    private Category getCategory(Blog blog, HttpServletRequest request) {
             /* 
    P/P       *  Method: Category getCategory(Blog, HttpServletRequest)
              * 
              *  Preconditions:
              *    request != null
              *    (soft) blog != null
              * 
              *  Postconditions:
              *    init'ed(return_value)
              * 
              *  Test Vectors:
              *    javax.servlet.http.HttpServletRequest:getParameter(...)@171: Addr_Set{null}, Inverse{null}
              */
   171      String categoryId = request.getParameter("category");
   172      if (categoryId != null) {
   173        return blog.getCategory(categoryId);
   174      } else {
   175        return null;
   176      }
   177    }
   178  
   179    /**
   180     * Helper method to find a named author from a request parameter.
   181     *
   182     * @param request   the HTTP request containing the tag parameter
   183     * @return  a String username, or null if the author isn't specified
   184     */
   185    private String getAuthor(HttpServletRequest request) {
             /* 
    P/P       *  Method: String getAuthor(HttpServletRequest)
              * 
              *  Preconditions:
              *    request != null
              * 
              *  Postconditions:
              *    init'ed(return_value)
              */
   186      return request.getParameter("author");
   187    }
   188  
   189  }