content: /**
   * Copyright 2014 55 Minutes (http://www.55minutes.com)
   *
   * Licensed 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 fiftyfive.wicket.feedback;
  
  import org.apache.wicket.Component;
  import org.apache.wicket.feedback.ContainerFeedbackMessageFilter;
  import org.apache.wicket.feedback.IFeedbackMessageFilter;
  import org.apache.wicket.markup.html.WebMarkupContainer;
  import org.apache.wicket.markup.html.form.FormComponent;
  import org.apache.wicket.markup.html.panel.FeedbackPanel;
  import org.apache.wicket.util.visit.IVisit;
  import org.apache.wicket.util.visit.IVisitor;
  
  /**
   * A markup container intended to hold a label, form field and feedback panel.
   * The container will gain the appropriate CSS class whenever feedback
   * messages are present.
   * <p>
   * Essentially this container takes care of some boilerplate Java code
   * needed for bundling a form field with a feedback panel. This way your form
   * displays validation messages along side each field.
   * <pre class="example">
   * &lt;tr wicket:id="username"&gt;
   *   &lt;th&gt;Username&lt;/th&gt;
   *   &lt;td&gt;
   *     &lt;input type="text" wicket:id="username" /&gt;
   *     &lt;wicket:container wicket:id="feedback"/&gt;
   *   &lt;/td&gt;
   * &lt;/tr&gt;
   * 
   * // The easy way:
   * add(new Prompt(new RequiredTextField("username")));
   * 
   * // Which is equivalent to all this:
   * FeedbackPanel feedback = new FeedbackPanel("feedback");
   * WebMarkupContainer username = new WebMarkupContainer("username")
   *     .add(new RequiredTextField("username").add(FeedbackStyle.INSTANCE))
   *     .add(feedback)
   *     .add(FeedbackStyle.INSTANCE);
   * feedback.setFilter(new ContainerFeedbackMessageFilter(username));</pre>
   * 
   * @since 2.0
   */
  public class Prompt extends WebMarkupContainer
  {
      public Prompt(String id)
      {
          super(id);
      }
      
      public Prompt(Component child)
      {
          super(child.getId());
          add(child);
      }
      
      @Override
      protected void onInitialize()
      {
          super.onInitialize();
          add(FeedbackStyle.INSTANCE);
          add(newFeedbackPanel("feedback"));
      }
      
      /**
       * Automatically adds FeedbackStyle to all FormComponents that are
       * children of this container.
       */
      @Override
      protected void onBeforeRender()
      {
          visitChildren(FormComponent.class, new IVisitor<FormComponent,Void>()
          {
              public void component(FormComponent fc, IVisit<Void> visit)
              {
                  fc.add(TempFeedbackStyle.INSTANCE);
              }
          });
          super.onBeforeRender();
      }
      
      protected FeedbackPanel newFeedbackPanel(String id)
      {
          IFeedbackMessageFilter f = new ContainerFeedbackMessageFilter(this);
          return new FeedbackPanel(id, f);
      }
      
      private static class TempFeedbackStyle extends FeedbackStyle
      {
          private static final TempFeedbackStyle INSTANCE = new TempFeedbackStyle();
          
          @Override
          public boolean isTemporary(Component comp)
          {
              return true;
          }
      }
  }
  