1.10.1. Using "pull"-style MVC

This snippet from the index.xhtml facelets page displays a list of recent blog entries:

<h:dataTable value="#{blog.recentBlogEntries}" var="blogEntry" rows="3">
   <h:column>
      <div class="blogEntry">
         <h3>#{blogEntry.title}</h3>
         <div>
            <h:outputText escape="false" 
                  value="#{blogEntry.excerpt==null ? blogEntry.body : blogEntry.excerpt}"/>
         </div>
         <p>
            <h:outputLink value="entry.seam" rendered="#{blogEntry.excerpt!=null}">
               <f:param name="blogEntryId" value="#{blogEntry.id}"/>
               Read more...
            </h:outputLink>
         </p>
         <p>
            [Posted on 
            <h:outputText value="#{blogEntry.date}">
               <f:convertDateTime timeZone="#{blog.timeZone}" locale="#{blog.locale}" 
	           type="both"/>
            </h:outputText>]
             
            <h:outputLink value="entry.seam">[Link]
               <f:param name="blogEntryId" value="#{blogEntry.id}"/>
            </h:outputLink>
         </p>
      </div>
   </h:column>
</h:dataTable>

Example 1.25.

If we navigate to this page from a bookmark, how does the data used by the <h:dataTable> actually get initialized? Well, what happens is that the Blog is retrieved lazily"pulled"when needed, by a Seam component named blog. This is the opposite flow of control to what is usual in traditional web action-based frameworks like Struts.

@Name("blog")
@Scope(ScopeType.STATELESS)
public class BlogService 
{
   
   @In
   private EntityManager entityManager;
  
   @Unwrap
   public Blog getBlog()
   {
      return (Blog) entityManager.createQuery("from Blog b left join fetch b.blogEntries")
            .setHint("org.hibernate.cacheable", true)
            .getSingleResult();
   }

}

	This component uses a seam-managed persistence context. Unlike the other examples we've seen, this persistence context is managed by Seam, instead of by the EJB3 container. The persistence context spans the entire web request, allowing us to avoid any exceptions that occur when accessing unfetched associations in the view.
	The `@Unwrap` annotation tells Seam to provide the return value of the methodthe `Blog`instead of the actual `BlogService` component to clients. This is the Seam manager component pattern.

Example 1.26.

This is good so far, but what about bookmarking the result of form submissions, such as a search results page?