/*
 *  Copyright 2008 biaoping.yin
 *
 *  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 org.frameworkset.web.servlet.view;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;

import org.frameworkset.spi.support.MessageSource;
import org.frameworkset.web.servlet.support.JstlUtils;
import org.frameworkset.web.servlet.support.RequestContext;

/**
 * <p>Title: JstlView.java</p> 
 * <p>Description: </p>
 * <p>bboss workgroup</p>
 * <p>Copyright (c) 2008</p>
 * @Date 2010-9-28
 * @author biaoping.yin
 * @version 1.0
 */
public class JstlView extends InternalResourceView {

	private MessageSource messageSource;


	/**
	 * Constructor for use as a bean.
	 * @see #setUrl
	 */
	public JstlView() {
	}

	/**
	 * Create a new JstlView with the given URL.
	 * @param url the URL to forward to
	 */
	public JstlView(String url) {
		super(url);
	}

	/**
	 * Create a new JstlView with the given URL.
	 * @param url the URL to forward to
	 * @param messageSource the MessageSource to expose to JSTL tags
	 * (will be wrapped with a JSTL-aware MessageSource that is aware of JSTL's
	 * <code>javax.servlet.jsp.jstl.fmt.localizationContext</code> context-param)
	 * @see JstlUtils#getJstlAwareMessageSource
	 */
	public JstlView(String url, MessageSource messageSource) {
		this(url);
		this.messageSource = messageSource;
	}


	/**
	 * Wraps the MessageSource with a JSTL-aware MessageSource that is aware
	 * of JSTL's <code>javax.servlet.jsp.jstl.fmt.localizationContext</code>
	 * context-param.
	 * @see JstlUtils#getJstlAwareMessageSource
	 */
	protected void initServletContext(ServletContext servletContext) {
		if (this.messageSource != null) {
			this.messageSource = JstlUtils.getJstlAwareMessageSource(servletContext, this.messageSource);
		}
		super.initServletContext(servletContext);
	}

	/**
	 * Exposes a JSTL LocalizationContext for 's locale and MessageSource.
	 * @see JstlUtils#exposeLocalizationContext
	 */
	protected void exposeHelpers(HttpServletRequest request) throws Exception {
		if (this.messageSource != null) {
			JstlUtils.exposeLocalizationContext(request, this.messageSource);
		}
		else {
			JstlUtils.exposeLocalizationContext(new RequestContext(request, getServletContext()));
		}
	}

}