/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.wicket.examples.ajax.builtin;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import org.apache.wicket.Component;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.ajax.attributes.AjaxRequestAttributes;
import org.apache.wicket.ajax.form.AjaxFormSubmitBehavior;
import org.apache.wicket.examples.guestbook.Comment;
import org.apache.wicket.markup.html.WebMarkupContainer;
import org.apache.wicket.markup.html.basic.Label;
import org.apache.wicket.markup.html.basic.MultiLineLabel;
import org.apache.wicket.markup.html.form.Form;
import org.apache.wicket.markup.html.form.TextArea;
import org.apache.wicket.markup.html.list.ListItem;
import org.apache.wicket.markup.html.list.ListView;
import org.apache.wicket.model.CompoundPropertyModel;
import org.apache.wicket.model.PropertyModel;
/**
* Ajax enabled example for the guestbook.
*
* @author Martijn Dashorst
*/
public class GuestBook extends BasePage
{
/** A global list of all comments from all users across all sessions */
public static final List<Comment> commentList = new ArrayList<>();
/** The list view that shows comments */
private final ListView<Comment> commentListView;
/** Container for the comments, used to update the listview. */
private final WebMarkupContainer comments;
/** The textarea for entering the comments, is updated in the ajax call. */
private Component text;
/**
* Constructor.
*/
public GuestBook()
{
// Add comment form
CommentForm commentForm = new CommentForm("commentForm");
add(commentForm);
// the WebMarkupContainer is used to update the listview in an ajax call
comments = new WebMarkupContainer("comments");
add(comments.setOutputMarkupId(true));
// Add commentListView of existing comments
comments.add(commentListView = new ListView<Comment>("comments",
new PropertyModel<>(this, "commentList"))
{
@Override
public void populateItem(final ListItem<Comment> listItem)
{
final Comment comment = listItem.getModelObject();
listItem.add(new Label("date", comment::getDate));
listItem.add(new MultiLineLabel("text", comment.getText()));
}
});
// The AjaxFormSubmitBehavior already calls the onSubmit of the form,
// all we need to do in the onSubmit(AjaxRequestTarget) handler is do our
// Ajax specific stuff, like rendering our components.
commentForm.add(new AjaxFormSubmitBehavior(commentForm, "submit")
{
@Override
protected void onSubmit(AjaxRequestTarget target)
{
// add the list of components that need to be updated
target.add(comments);
target.add(text);
// focus the textarea again
target.appendJavaScript("document.getElementById('" + text.getMarkupId() +
"').focus();");
}
@Override
protected void onError(AjaxRequestTarget target)
{
}
@Override
protected void updateAjaxAttributes(AjaxRequestAttributes attributes)
{
super.updateAjaxAttributes(attributes);
// we need to cancel the standard submit of the form in the onsubmit
// handler,
// otherwise we'll get double submits. To do so, we return false after
// the
// ajax submit has occurred.
attributes.setPreventDefault(true);
}
});
}
/**
* A form that allows a user to add a comment.
*
* @author Jonathan Locke
*/
private final class CommentForm extends Form<Comment>
{
/**
* Constructor
*
* @param id
* The name of this component
*/
private CommentForm(final String id)
{
// Construct form with no validation listener
super(id, new CompoundPropertyModel<>(new Comment()));
// Add text entry widget
text = new TextArea<>("text").setOutputMarkupId(true);
add(text);
}
/**
* Show the resulting valid edit
*/
@Override
public final void onSubmit()
{
// Construct a copy of the edited comment
final Comment comment = getModelObject();
final Comment newComment = new Comment(comment);
// Set date of comment to add
newComment.setDate(new Date());
// Add the component we edited to the list of comments
commentList.add(0, newComment);
// Clear out the text component
comment.setText("");
}
}
/**
* Clears the comments.
*/
public static void clear()
{
commentList.clear();
}
}