1  /*
     2   * Licensed to the Apache Software Foundation (ASF) under one or more
     3   *  contributor license agreements.  The ASF licenses this file to You
     4   * under the Apache License, Version 2.0 (the "License"); you may not
     5   * use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   *     http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.  For additional information regarding
    15   * copyright in this work, please see the NOTICE file in the top level
    16   * directory of this distribution.
    17   */
    18  
    19  package org.apache.roller.weblogger.ui.struts2.pagers;
    20  
    21  import java.util.HashMap;
    22  import java.util.List;
    23  import java.util.Map;
    24  import org.apache.commons.logging.Log;
    25  import org.apache.commons.logging.LogFactory;
    26  import org.apache.roller.weblogger.pojos.WeblogEntryComment;
    27  import org.apache.roller.weblogger.util.URLUtilities;
    28  
    29  
    30  /**
    31   * Paging through a collection of comments.
    32   */
    33  public class CommentsPager {
    34      
             /* 
    P/P       *  Method: org.apache.roller.weblogger.ui.struts2.pagers.CommentsPager__static_init
              * 
              *  Postconditions:
              *    init'ed(log)
              */
    35      private static final Log log = LogFactory.getLog(CommentsPager.class);
    36      
    37      // the collection for the pager
    38      private final List<WeblogEntryComment> items;
    39      
    40      // base url for the pager
    41      private final String baseUrl;
    42      
    43      // what page we are on
    44      private final int pageNum;
    45      
    46      // are there more items?
    47      private final boolean moreItems;
    48      
    49      
             /* 
    P/P       *  Method: void org.apache.roller.weblogger.ui.struts2.pagers.CommentsPager(String, int, List, bool)
              * 
              *  Postconditions:
              *    this.baseUrl == url
              *    init'ed(this.baseUrl)
              *    this.items == comments
              *    init'ed(this.items)
              *    this.moreItems == hasMore
              *    init'ed(this.moreItems)
              *    this.pageNum == page
              *    init'ed(this.pageNum)
              */
    50      public CommentsPager(String url, int page, List<WeblogEntryComment> comments, boolean hasMore) {
    51          this.baseUrl = url;
    52          this.pageNum = page;
    53          this.items = comments;
    54          this.moreItems = hasMore;
    55      }
    56      
    57      
    58      public String getNextLink() {
                 /* 
    P/P           *  Method: String getNextLink()
                  * 
                  *  Preconditions:
                  *    (soft) this.baseUrl != null
                  *    (soft) this.pageNum <= 232-2
                  * 
                  *  Postconditions:
                  *    init'ed(java.lang.StringBuilder:toString(...)._tainted)
                  *    return_value in Addr_Set{null,&java.lang.StringBuilder:toString(...),&java.lang.StringBuilder:toString(...)}
                  * 
                  *  Test Vectors:
                  *    this.moreItems: {0}, {1}
                  */
    59          if(isMoreItems()) {
    60              int nextPage = pageNum + 1;
    61              Map<String, String> params = new HashMap();
    62              params.put("bean.page", ""+nextPage);
    63              return createURL(baseUrl, params);
    64          }
    65          return null;
    66      }
    67      
    68      
    69      public String getPrevLink() {
                 /* 
    P/P           *  Method: String getPrevLink()
                  * 
                  *  Preconditions:
                  *    (soft) this.baseUrl != null
                  * 
                  *  Postconditions:
                  *    init'ed(java.lang.StringBuilder:toString(...)._tainted)
                  *    return_value in Addr_Set{null,&java.lang.StringBuilder:toString(...),&java.lang.StringBuilder:toString(...)}
                  * 
                  *  Test Vectors:
                  *    this.pageNum: {-231..0}, {1..232-1}
                  */
    70          if (pageNum > 0) {
    71              int prevPage = pageNum - 1;
    72              Map<String, String> params = new HashMap();
    73              params.put("bean.page", ""+prevPage);
    74              return createURL(baseUrl, params);
    75          }
    76          return null;
    77      }
    78      
    79      
    80      private String createURL(String base, Map<String, String> params) {
                 /* 
    P/P           *  Method: String createURL(String, Map)
                  * 
                  *  Preconditions:
                  *    base != null
                  * 
                  *  Presumptions:
                  *    org.apache.roller.weblogger.util.URLUtilities:getQueryString(...)@81 != null
                  * 
                  *  Postconditions:
                  *    init'ed(java.lang.StringBuilder:toString(...)._tainted)
                  *    return_value in Addr_Set{&java.lang.StringBuilder:toString(...),&java.lang.StringBuilder:toString(...)}
                  * 
                  *  Test Vectors:
                  *    java.lang.String:indexOf(...)@83: {-1}, {-231..-2, 0..232-1}
                  */
    81          String qString = URLUtilities.getQueryString(params);
    82          
    83          if(base.indexOf("?") != -1) {
    84              // if base url already has params them just append our query string
    85              return base + "&" + qString.substring(1);
    86          } else {
    87              return base + qString;
    88          }
    89      }
    90      
    91      
    92      public List<WeblogEntryComment> getItems() {
                 /* 
    P/P           *  Method: List getItems()
                  * 
                  *  Postconditions:
                  *    return_value == this.items
                  *    init'ed(return_value)
                  */
    93          return items;
    94      }
    95  
    96      public boolean isMoreItems() {
                 /* 
    P/P           *  Method: bool isMoreItems()
                  * 
                  *  Postconditions:
                  *    return_value == this.moreItems
                  *    init'ed(return_value)
                  */
    97          return moreItems;
    98      }
    99      
   100  }