/*
* 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.compref;
import java.util.Arrays;
import java.util.List;
import org.apache.wicket.examples.WicketExamplePage;
import org.apache.wicket.markup.html.form.ChoiceRenderer;
import org.apache.wicket.markup.html.form.DropDownChoice;
import org.apache.wicket.markup.html.form.Form;
import org.apache.wicket.markup.html.panel.FeedbackPanel;
import org.apache.wicket.model.CompoundPropertyModel;
import org.apache.wicket.util.io.IClusterable;
/**
* Page with examples on {@link org.apache.wicket.markup.html.form.DropDownChoice}.
*
* @author Eelco Hillenius
*/
public class DropDownChoicePage extends WicketExamplePage
{
/** available sites for selection. */
private static final List<String> SITES = Arrays.asList("The Server Side", "Java Lobby", "Java.Net");
/** available numbers for selection. */
private static final List<Integer> INTEGERS = Arrays.asList(1, 2, 3);
/**
* Constructor
*/
public DropDownChoicePage()
{
final Input input = new Input();
setDefaultModel(new CompoundPropertyModel<>(input));
// Add a FeedbackPanel for displaying our messages
FeedbackPanel feedbackPanel = new FeedbackPanel("feedback");
add(feedbackPanel);
// Add a form with an onSumbit implementation that sets a message
Form<Void> form = new Form<Void>("form")
{
@Override
protected void onSubmit()
{
info("input: " + input);
}
};
add(form);
// Add a dropdown choice component that uses Input's 'site' property to
// designate the
// current selection, and that uses the SITES list for the available
// options.
// Note that when the selection is null, Wicket will lookup a localized
// string to
// represent this null with key: "id + '.null'". In this case, this is
// 'site.null'
// which can be found in DropDownChoicePage.properties
form.add(new DropDownChoice<>("site", SITES));
// Although the default behavior of displaying the string
// representations of the choices
// by calling toString on the object might be alright in some cases, you
// usually want to have
// more control over it. You achieve this by providing an instance of
// IChoiceRenderer,
// like the example below. Don't forget to check out the default
// implementation of
// IChoiceRenderer, ChoiceRenderer.
form.add(new DropDownChoice<>("integer", INTEGERS, new ChoiceRenderer<Integer>()
{
/**
* Gets the display value that is visible to the end user.
*
* @see org.apache.wicket.markup.html.form.IChoiceRenderer#getDisplayValue(java.lang.Object)
*/
@Override
public Object getDisplayValue(Integer value)
{
// Use an ugly switch statement. Usually you would hide this in
// your business
// object or in a utility.
switch (value)
{
case 1 :
return "One";
case 2 :
return "Two";
case 3 :
return "Three";
default :
throw new IllegalStateException(value + " is not mapped!");
}
}
/**
* Gets the value that is invisible to the end user, and that is used as the selection
* id.
*
* @see org.apache.wicket.markup.html.form.IChoiceRenderer#getIdValue(java.lang.Object,
* int)
*/
@Override
public String getIdValue(Integer object, int index)
{
// though we could do kind of the reverse of what we did in
// getDisplayValue,
// just using your index in the list of provided options is
// usually more
// convenient
return String.valueOf(INTEGERS.get(index));
}
}));
}
/** Simple data class that acts as a model for the input fields. */
private static class Input implements IClusterable
{
/** the selected site. */
public String site;
/** the selected integer. */
public Integer integer = INTEGERS.get(0);
@Override
public String toString()
{
return "site = '" + site + "', integer = " + integer;
}
}
/**
* Override base method to provide an explanation
*/
@Override
protected void explain()
{
String html = "<select wicket:id=\"site\">\n" + " <option>site 1</option>\n"
+ " <option>site 2</option>\n" + "</select>\n" + "<select wicket:id=\"integer\">\n"
+ " <option>Fifty</option>\n" + " <option>Sixty</option>\n" + "</select>";
String code = "/** available sites for selection. */\n"
+ "private static final List SITES = Arrays.asList(new String[] {\"The Server Side\", \"Java Lobby\", \"Java.Net\" });\n"
+ "/** available numbers for selection. */\n"
+ "private static final List INTEGERS = Arrays.asList(new Integer[] { new Integer(1), new Integer(2), new Integer(3) });\n"
+ "\n"
+ "public DropDownChoicePage() {\n"
+ " ...\n"
+ " // Add a dropdown choice component that uses the model object's 'site' property to designate the\n"
+ " // current selection, and that uses the SITES list for the available options.\n"
+ " // Note that when the selection is null, Wicket will lookup a localized string to\n"
+ " // represent this null with key: \"id + '.null'\". In this case, this is 'site.null'\n"
+ " // which can be found in DropDownChoicePage.properties\n"
+ " form.add(new DropDownChoice(\"site\", SITES));\n"
+ "\n"
+ " // Allthough the default behavior of displaying the string representations of the choices\n"
+ " // by calling toString on the object might be alright in some cases, you usually want to have\n"
+ " // more control over it. You achieve this by providing an instance of IChoiceRenderer.\n"
+ " // Don't forget to check out the default implementation of IChoiceRenderer, ChoiceRenderer.\n"
+ " form.add(new DropDownChoice(\"integer\", INTEGERS, new IChoiceRenderer() {\n"
+ " // Gets the display value that is visible to the end user.\n"
+ " public String getDisplayValue(Object object) {\n"
+ " ...\n"
+ " }\n"
+ "\n"
+ " // Gets the value that is invisble to the end user, and that is used as the selection id.\n"
+ " public String getIdValue(Object object, int index) {\n"
+ " ...\n"
+ " }\n"
+ " }));\n" + "}";
add(new ExplainPanel(html, code));
}
}