/* 
    P/P   *  Method: net.sourceforge.pebble.decorator.EscapeMarkupDecorator__static_init
          */
     1  package net.sourceforge.pebble.decorator;
     2  
     3  import net.sourceforge.pebble.domain.BlogEntry;
     4  import net.sourceforge.pebble.domain.StaticPage;
     5  import net.sourceforge.pebble.util.StringUtils;
     6  import net.sourceforge.pebble.api.decorator.ContentDecoratorContext;
     7  
     8  import java.util.regex.Matcher;
     9  import java.util.regex.Pattern;
    10  
    11  /**
    12   * Escapes < and > tags in the excerpt/body of blog entries and
    13   * the body of static pages.
    14   * 
    15   * @author Simon Brown
    16   */
         /* 
    P/P   *  Method: void net.sourceforge.pebble.decorator.EscapeMarkupDecorator()
          */
    17  public class EscapeMarkupDecorator extends ContentDecoratorSupport {
    18  
    19    private static final String ESCAPE_START_TAG = "<escape>";
    20    private static final String ESCAPE_END_TAG = "</escape>";
    21  
    22    /**
    23     * Decorates the specified blog entry.
    24     *
    25     * @param context   the context in which the decoration is running
    26     * @param blogEntry the blog entry to be decorated
    27     */
    28    public void decorate(ContentDecoratorContext context, BlogEntry blogEntry) {
             /* 
    P/P       *  Method: void decorate(ContentDecoratorContext, BlogEntry)
              * 
              *  Preconditions:
              *    blogEntry != null
              *    blogEntry.propertyChangeSupport != null
              *    init'ed(blogEntry.body)
              *    init'ed(blogEntry.excerpt)
              * 
              *  Postconditions:
              *    blogEntry.body != null
              *    init'ed(blogEntry.excerpt)
              */
    29      String escapedBody = escape(blogEntry.getBody());
    30      blogEntry.setBody(escapedBody);
    31  
    32      String escapedExcerpt = escape(blogEntry.getExcerpt());
    33      blogEntry.setExcerpt(escapedExcerpt);
    34    }
    35  
    36    /**
    37     * Decorates the specified static page.
    38     *
    39     * @param context    the context in which the decoration is running
    40     * @param staticPage the static page to be decorated
    41     */
    42    public void decorate(ContentDecoratorContext context, StaticPage staticPage) {
             /* 
    P/P       *  Method: void decorate(ContentDecoratorContext, StaticPage)
              * 
              *  Preconditions:
              *    staticPage != null
              *    init'ed(staticPage.body)
              *    staticPage.propertyChangeSupport != null
              * 
              *  Postconditions:
              *    staticPage.body != null
              */
    43      String escapedBody = escape(staticPage.getBody());
    44      staticPage.setBody(escapedBody);
    45    }
    46  
    47    private String escape(String content) {
    48      // is there work to do?
             /* 
    P/P       *  Method: String escape(String)
              * 
              *  Presumptions:
              *    java.lang.String:length(...)@68 - java.lang.String:length(...)@68 in -232+1..231
              *    java.util.regex.Pattern:compile(...)@57 != null
              *    java.util.regex.Pattern:matcher(...)@59 != null
              * 
              *  Postconditions:
              *    return_value != null
              * 
              *  Test Vectors:
              *    content: Addr_Set{null}, Inverse{null}
              *    java.lang.String:length(...)@49: {1..232-1}, {0}
              *    java.util.regex.Matcher:find(...)@62: {1}, {0}
              */
    49      if (content == null || content.length() == 0) {
    50        return "";
    51      }
    52  
    53      // this pattern says "take the shortest match you can find where there are
    54      // one or more characters between escape tags"
    55      //  - the match is case insensitive and DOTALL means that newlines are
    56      //  - considered as a character match
    57      Pattern p = Pattern.compile(ESCAPE_START_TAG + ".+?" + ESCAPE_END_TAG,
    58          Pattern.CASE_INSENSITIVE | Pattern.DOTALL);
    59      Matcher m = p.matcher(content);
    60  
    61      // while there are blocks to be escaped
    62      while (m.find()) {
    63        int start = m.start();
    64        int end = m.end();
    65  
    66        // grab the text, strip off the escape tags and transform it
    67        String textToEscape = content.substring(start, end);
    68        textToEscape = textToEscape.substring(ESCAPE_START_TAG.length(), textToEscape.length() - ESCAPE_END_TAG.length());
    69        textToEscape = StringUtils.transformHTML(textToEscape);
    70  
    71        // now add it back into the original text
    72        content = content.substring(0, start) + textToEscape + content.substring(end, content.length());
    73        m = p.matcher(content);
    74      }
    75  
    76      return content;
    77    }
    78  
    79  }