wicket-extensions/src/java/wicket/extensions/markup/html/form/select/Select.java

/*
 * $Id$ $Revision$
 * $Date$
 * 
 * ==============================================================================
 * 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 wicket.extensions.markup.html.form.select;

import java.util.Collection;

import wicket.WicketRuntimeException;
import wicket.markup.html.WebMarkupContainer;
import wicket.markup.html.form.FormComponent;
import wicket.model.IModel;

/**
 * Component that represents a <code>&lt;select&gt;</code> box. Elements are
 * provided by one or more <code>SelectChoice</code> or
 * <code>SelectOptions</code> components in the hierarchy below the
 * <code>Select</code> component.
 * 
 * Advantages to the standard choice components is that the user has a lot more
 * control over the markup between the &lt;select&gt; tag and its children
 * &lt;option&gt; tags: allowing for such things as &lt;optgroup&gt; tags.
 * 
 * TODO Post 1.2: General: Example
 * 
 * @see SelectOption
 * @see SelectOptions
 * 
 * @author Igor Vaynberg (ivaynberg@users.sf.net)
 */
public class Select extends FormComponent
{
	private static final long serialVersionUID = 1L;

	/**
	 * Constructor that will create a default model collection
	 * 
	 * @param id
	 *            component id
	 */
	public Select(String id)
	{
		super(id);
	}

	/**
	 * @see WebMarkupContainer#WebMarkupContainer(String, IModel)
	 */
	public Select(String id, IModel model)
	{
		super(id, model);
	}

	/**
	 * @see FormComponent#updateModel()
	 */
	public void updateModel()
	{
		modelChanging();

		Object object = getModelObject();
		boolean isModelCollection = object instanceof Collection;

		/*
		 * clear the model
		 */
		if (isModelCollection)
		{
			((Collection)object).clear();
		}
		else
		{
			getModel().setObject(this, null);
		}

		/*
		 * the input contains an array of full path of the selected option
		 * components unless nothing was selected in which case the input
		 * contains null
		 */
		String[] paths = inputAsStringArray();

		/*
		 * if the input is null we do not need to do anything since the model
		 * collection has already been cleared
		 */

		if (paths != null && paths.length > 0)
		{
			if (!isModelCollection && paths.length > 1)
			{
				throw new WicketRuntimeException(
						"The model of Select component ["
								+ getPath()
								+ "] is not of type java.util.Collection, but more then one SelectOption component has been selected. Either remove the multiple attribute from the select tag or make the model of the Select component a collection");
			}

			for (int i = 0; i < paths.length; i++)
			{
				String path = paths[i];

				if (path != null)
				{
					/*
					 * option component path sans select component path =
					 * relative path from group to option since we know the
					 * option is child of select
					 */

					path = path.substring(getPath().length() + 1);

					// retrieve the selected checkbox component
					SelectOption option = (SelectOption)get(path);

					if (option == null)
					{
						throw new WicketRuntimeException(
								"submitted http post value ["
										+ paths.toString()
										+ "] for SelectOption component ["
										+ getPath()
										+ "] contains an illegal relative path element ["
										+ path
										+ "] which does not point to an SelectOption component. Due to this the Select component cannot resolve the selected SelectOption component pointed to by the illegal value. A possible reason is that component hierarchy changed between rendering and form submission.");
					}

					// assign the value
					if (isModelCollection)
					{
						((Collection)object).add(option.getModelObject());
					}
					else
					{
						setModelObject(option.getModelObject());
					}
				}
			}
		}

		modelChanged();
	}
}