/*
 * Copyright 2002-2018 the original author or authors.
 *
 * 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.springframework.web.servlet.view.feed;

import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.rometools.rome.feed.atom.Entry;
import com.rometools.rome.feed.atom.Feed;

Abstract superclass for Atom Feed views, using the
ROME package.
>NOTE: As of Spring 4.1, this is based on the com.rometools variant of ROME, version 1.5. Please upgrade your build dependency.
Application-specific view classes will extend this class. The view will be held in the subclass itself, not in a template. Main entry points are the AbstractFeedView<Feed>.buildFeedMetadata and buildFeedEntries. 
Thanks to Jettro Coenradie and Sergio Bossa for the original feed view prototype!
Author:
Arjen Poutsma, Juergen Hoeller
See Also:
AbstractFeedView<Feed>.buildFeedMetadata
buildFeedEntries
Atom Syndication Format
Since:
3.0/**
 * Abstract superclass for Atom Feed views, using the
 * <a href="https://github.com/rometools/rome">ROME</a> package.
 *
 * <p>><b>NOTE: As of Spring 4.1, this is based on the {@code com.rometools}
 * variant of ROME, version 1.5. Please upgrade your build dependency.</b>
 *
 * <p>Application-specific view classes will extend this class.
 * The view will be held in the subclass itself, not in a template.
 * Main entry points are the {@link #buildFeedMetadata} and {@link #buildFeedEntries}.
 *
 * <p>Thanks to Jettro Coenradie and Sergio Bossa for the original feed view prototype!
 *
 * @author Arjen Poutsma
 * @author Juergen Hoeller
 * @since 3.0
 * @see #buildFeedMetadata
 * @see #buildFeedEntries
 * @see <a href="http://www.atomenabled.org/developers/syndication/">Atom Syndication Format</a>
 */
public abstract class AbstractAtomFeedView extends AbstractFeedView<Feed> {

	
The default feed type used.
/**
	 * The default feed type used.
	 */
	public static final String DEFAULT_FEED_TYPE = "atom_1.0";

	private String feedType = DEFAULT_FEED_TYPE;


	public AbstractAtomFeedView() {
		setContentType("application/atom+xml");
	}

	
Set the Rome feed type to use.
Defaults to Atom 1.0.
See Also:
setFeedType.setFeedType(String)
DEFAULT_FEED_TYPE/**
	 * Set the Rome feed type to use.
	 * <p>Defaults to Atom 1.0.
	 * @see Feed#setFeedType(String)
	 * @see #DEFAULT_FEED_TYPE
	 */
	public void setFeedType(String feedType) {
		this.feedType = feedType;
	}

	
Create a new Feed instance to hold the entries.
By default returns an Atom 1.0 feed, but the subclass can specify any Feed.
See Also:
setFeedType(String)/**
	 * Create a new Feed instance to hold the entries.
	 * <p>By default returns an Atom 1.0 feed, but the subclass can specify any Feed.
	 * @see #setFeedType(String)
	 */
	@Override
	protected Feed newFeed() {
		return new Feed(this.feedType);
	}

	
Invokes buildFeedEntries(Map<String,Object>, HttpServletRequest, HttpServletResponse) to get a list of feed entries. /**
	 * Invokes {@link #buildFeedEntries(Map, HttpServletRequest, HttpServletResponse)}
	 * to get a list of feed entries.
	 */
	@Override
	protected final void buildFeedEntries(Map<String, Object> model, Feed feed,
			HttpServletRequest request, HttpServletResponse response) throws Exception {

		List<Entry> entries = buildFeedEntries(model, request, response);
		feed.setEntries(entries);
	}

	
Subclasses must implement this method to build feed entries, given the model.
Note that the passed-in HTTP response is just supposed to be used for
setting cookies or other HTTP headers. The built feed itself will automatically
get written to the response after this method returns.
Params:
model – 	the model Map
request – in case we need locale etc. Shouldn't look at attributes.
response – in case we need to set cookies. Shouldn't write to it.
Throws:
Exception – any exception that occurred during document building
See Also:
Entry
Returns:
the feed entries to be added to the feed/**
	 * Subclasses must implement this method to build feed entries, given the model.
	 * <p>Note that the passed-in HTTP response is just supposed to be used for
	 * setting cookies or other HTTP headers. The built feed itself will automatically
	 * get written to the response after this method returns.
	 * @param model	the model Map
	 * @param request in case we need locale etc. Shouldn't look at attributes.
	 * @param response in case we need to set cookies. Shouldn't write to it.
	 * @return the feed entries to be added to the feed
	 * @throws Exception any exception that occurred during document building
	 * @see Entry
	 */
	protected abstract List<Entry> buildFeedEntries(
			Map<String, Object> model, HttpServletRequest request, HttpServletResponse response)
			throws Exception;

}