1.9.2. Bookmarkable search results page

The blog example has a small form at the top right of each page that allows the user to search for blog entries. This is defined in menu.xhtml, which is included by the Facelets template template.xhtml: 
<div id="search"> 
  <h:form> 
    <h:inputText value="#{searchAction.searchPattern}"/> 
    <h:commandButton value="Search" action="/search.xhtml"/> 
  </h:form> 
</div>
To implement a bookmarkable search results page, after the search form submission is processed, we must perform a browser redirect. Because the JSF view ID is used as the action outcome, Seam automatically redirects to the view ID when the form is submitted. We could also have defined a navigation rule as follows: 
<navigation-rule> 
  <navigation-case> 
    <from-outcome>searchResults</from-outcome> 
    <to-view-id>/search.xhtml</to-view-id> 
    <redirect/> 
  </navigation-case> 
</navigation-rule>
In that case, the form would have looked like this: 
<div id="search"> 
  <h:form> 
    <h:inputText value="#{searchAction.searchPattern}"/> 
    <h:commandButton value="Search" action="searchResults"/> 
  </h:form> 
</div>
However, to get a bookmarkable URL like http://localhost:8080/seam-blog/search/, the values submitted with the form must be included in the URL. There is no easy way to do this with JSF, but with Seam, only two features are required: page parameters and URL rewriting. Both are defined here in WEB-INF/pages.xml: 
 <pages>
  <page view-id="/search.xhtml">
    <rewrite pattern="/search/{searchPattern}"/> 
    <rewrite pattern="/search"/>

    <param name="searchPattern" value="#{searchService.searchPattern}"/>

  </page>
  ...
</pages>
The page parameter instructs Seam to link the searchPattern request parameter to the value held by #{searchService.searchPattern}, whenever the search page is requested, and whenever a link to the search page is generated. Seam takes responsibility for maintaining the link between URL state and application state.
The URL for a search on the term book would ordinarily be http://localhost:8080/seam-blog/seam/search.xhtml?searchPattern=book. Seam can simplify this URL by using a rewrite rule. The first rewrite rule, for the pattern /search/{searchPattern}, states that whenever a URL for search.xhtml contains a searchPattern request parameter, that URL can be compressed into a simplified URL. So, the earlier URL (http://localhost:8080/seam-blog/seam/search.xhtml?searchPattern= book) can instead be written as http://localhost:8080/seam-blog/search/book.
As with page parameters, rewriting URLs is bidirectional. This means that Seam forwards requests for the simplified URL to the correct view, and it automatically generates the simplified view — users need not construct URLs. The entire process is handled transparently. The only requirement for rewriting URLs is to enable the rewrite filter in components.xml: 
<web:rewrite-filter view-mapping="/seam/*" />
The redirect takes us to the search.xhtml page: 
<h:dataTable value="#{searchResults}" var="blogEntry">
 <h:column>
   <div>
      <s:link view="/entry.xhtml" propagation="none" 
              value="#{blogEntry.title}">
        <f:param name="blogEntryId" value="#{blogEntry.id}"/>
      </s:link>
      posted on 
      <h:outputText value="#{blogEntry.date}">
        <f:convertDateTime timeZone="#{blog.timeZone}" 
                           locale="#{blog.locale}" type="both"/>
      </h:outputText>
    </div>
  </h:column>
</h:dataTable>
Again, this uses "pull"-style MVC to retrieve the search results with Hibernate Search. 
@Name("searchService")
public class SearchService {
   
  @In
  private FullTextEntityManager entityManager;
   
  private String searchPattern;
   
  @Factory("searchResults")
  public List<BlogEntry> getSearchResults() {
  if (searchPattern==null || "".equals(searchPattern) )
    {
      searchPattern = null;
      return entityManager.createQuery(
                "select be from BlogEntry be order by date desc"
              ).getResultList();
    }
      else
        {
          Map<String,Float> boostPerField = new HashMap<String,Float>();
          boostPerField.put( "title", 4f );
          boostPerField.put( "body", 1f );
          String[] productFields = {"title", "body"};
          QueryParser parser = new MultiFieldQueryParser(productFields, 
                               new StandardAnalyzer(), boostPerField);
          parser.setAllowLeadingWildcard(true);
          org.apache.lucene.search.Query luceneQuery;
          try
            {
              luceneQuery = parser.parse(searchPattern);
            }
          catch (ParseException e)
            {
              return null;
            }

          return entityManager
            .createFullTextQuery(luceneQuery, BlogEntry.class)
            .setMaxResults(100)
            .getResultList();
        }
    }

    public String getSearchPattern()
    {
      return searchPattern;
    }

    public void setSearchPattern(String searchPattern)
    {
      this.searchPattern = searchPattern;
    }

}