THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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The Comment POJO model is very straightforward (we have omitted the getter/setter code for brevity in this example):
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package wicket.examples.guestbook;
import java.io.Serializable;
import java.util.Date;
public class Comment implements Serializable
{
public String text;
public Date date = new Date();
}
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The implementation below obtains the Comment POJO from the list item and adds label components for the date and text of the Comment. This is all accomplished in just a few lines of code.
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package wicket.examples.guestbook;
import java.util.Date;
import java.util.List;
import java.util.Vector;
import wicket.markup.html.WebPage;
import wicket.markup.html.basic.Label;
import wicket.markup.html.basic.MultiLineLabel;
import wicket.markup.html.form.Form;
import wicket.markup.html.form.TextArea;
import wicket.markup.html.list.ListItem;
import wicket.markup.html.list.ListView;
import wicket.model.PropertyModel;
public final class GuestBook extends WebPage
{
/** Use a Vector, as it is synchronized. */
private static final List commentList = new Vector();
private final ListView commentListView;
public GuestBook()
{
add(new CommentForm("commentForm"));
add(commentListView = new ListView("comments", commentList)
{
public void populateItem(final ListItem listItem)
{
final Comment comment = (Comment)listItem.getModelObject();
listItem.add(new Label("date", comment.date.toString()));
listItem.add(new MultiLineLabel("text", comment.text));
}
});
}
public final class CommentForm extends Form
{
private final Comment comment = new Comment();
public CommentForm(final String componentName)
{
super(componentName);
add(new TextArea("text", new PropertyModel(comment, "text")));
}
public final void onSubmit()
{
final Comment newComment = new Comment();
newComment.text = comment.text;
commentList.add(0, newComment);
commentListView.modelChanged();
comment.text = "";
}
}
}
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Finally, notice the <wicket:remove> block. This is simply markup that is there for previewing purposes only. When the page renders, it is stripped out.
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<html>
<body>
<form wicket:id = "commentForm">
Add your comment here:
<p>
<textarea wicket:id = "text">This is a comment</textarea>
<p>
<input type = "submit" value = "Submit"/>
</form>
<p>
<span wicket:id = "comments">
<p>
<span wicket:id = "date">1/1/2004</span><br>
<span wicket:id = "text">Comment text goes here.</span>
</p>
</span>
<wicket:remove>
<p>
1/2/2004<br/>
More comment text here.
</p>
</wicket:remove>
</body>
</html>
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For completeness, we've included the GuestBookApplication class, and as a final treat the modifications to the web.xml file.
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package wicket.examples.guestbook;
import wicket.protocol.http.WebApplication;
public class GuestBookApplication extends WebApplication
{
public GuestBookApplication()
{
}
public Class getHomePage()
{
return GuestBook.class;
}
}
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Add the following two sections (servlet and servlet-mapping) to your web.xml file for running this application.
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<servlet>
<servlet-name>GuestBookApplication</servlet-name>
<servlet-class>wicket.protocol.http.WicketServlet</servlet-class>
<init-param>
<param-name>applicationClassName</param-name>
<param-value>wicket.examples.guestbook.GuestBookApplication</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>GuestBookApplication</servlet-name>
<url-pattern>/app/*</url-pattern>
</servlet-mapping>
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