DefaultWatchListEventFeedManager.java

/*
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.xwiki.watchlist.internal;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import javax.inject.Inject;
import javax.inject.Provider;
import javax.inject.Singleton;

import org.apache.commons.collections.ListUtils;
import org.apache.commons.collections.Transformer;
import org.apache.commons.collections.functors.ConstantTransformer;
import org.apache.commons.lang3.StringUtils;
import org.xwiki.component.annotation.Component;
import org.xwiki.localization.ContextualLocalizationManager;
import org.xwiki.watchlist.internal.api.WatchListEventFeedManager;
import org.xwiki.watchlist.internal.api.WatchListStore;
import org.xwiki.watchlist.internal.api.WatchedElementType;

import com.sun.syndication.feed.synd.SyndFeed;
import com.xpn.xwiki.XWikiContext;
import com.xpn.xwiki.XWikiException;
import com.xpn.xwiki.plugin.activitystream.plugin.ActivityEvent;
import com.xpn.xwiki.plugin.activitystream.plugin.ActivityStreamPluginApi;

/**
 * Default implementation for {@link WatchListEventFeedManager}.
 * 
 * @version $Id: 2806c84318aee4c18846671edfbca530f3937772 $
 */
@Component
@Singleton
public class DefaultWatchListEventFeedManager implements WatchListEventFeedManager
{
    /**
     * The watchlist store component instance.
     */
    @Inject
    private WatchListStore store;

    /**
     * Used to resolve translations.
     */
    @Inject
    private ContextualLocalizationManager localization;

    /**
     * Used to obtain the current context.
     */
    @Inject
    private Provider<XWikiContext> contextProvider;

    @Override
    @SuppressWarnings("unchecked")
    public SyndFeed getFeed(String user, int entryNumber) throws XWikiException
    {
        XWikiContext context = contextProvider.get();

        Collection<String> wikis = store.getWatchedElements(user, WatchedElementType.WIKI);
        Collection<String> spaces = store.getWatchedElements(user, WatchedElementType.SPACE);
        Collection<String> documents = store.getWatchedElements(user, WatchedElementType.DOCUMENT);
        List<Object> parameters = new ArrayList<Object>();
        ActivityStreamPluginApi asApi =
            (ActivityStreamPluginApi) context.getWiki().getPluginApi("activitystream", context);

        parameters.addAll(wikis);
        parameters.addAll(spaces);
        parameters.addAll(documents);

        Transformer transformer = new ConstantTransformer("?");
        List<String> wikisPlaceholders = ListUtils.transformedList(new ArrayList<String>(), transformer);
        wikisPlaceholders.addAll(wikis);
        List<String> spacesPlaceholders = ListUtils.transformedList(new ArrayList<String>(), transformer);
        spacesPlaceholders.addAll(spaces);
        List<String> documentsPlaceholders = ListUtils.transformedList(new ArrayList<String>(), transformer);
        documentsPlaceholders.addAll(documents);

        String listItemsJoint = ",";
        String concatWiki = " or concat(act.wiki,'";
        String query = "1=0";
        if (!wikis.isEmpty()) {
            query += " or act.wiki in (" + StringUtils.join(wikisPlaceholders, listItemsJoint) + ')';
        }
        if (!spaces.isEmpty()) {
            query +=
                concatWiki + DefaultWatchListStore.WIKI_SPACE_SEP + "',act.space) in ("
                    + StringUtils.join(spacesPlaceholders, listItemsJoint) + ')';
        }
        if (!documents.isEmpty()) {
            query +=
                concatWiki + DefaultWatchListStore.WIKI_SPACE_SEP + "',act.page) in ("
                    + StringUtils.join(documentsPlaceholders, listItemsJoint) + ')';
        }
        List<ActivityEvent> events = asApi.searchEvents(query, false, true, entryNumber, 0, parameters);

        SyndFeed feed = asApi.getFeed(events);
        setFeedMetaData(feed, context);

        return feed;
    }

    /**
     * Set the standard feed metadata values, based on static translated messages and wiki configuration.
     *
     * @param feed the feed to configure
     * @param context the current request context
     * @throws XWikiException if the wiki can't be properly accessed
     */
    private void setFeedMetaData(SyndFeed feed, XWikiContext context) throws XWikiException
    {
        String msgPrefix = DefaultWatchList.APP_RES_PREFIX + "rss.";

        feed.setAuthor(localization.getTranslationPlain(msgPrefix + "author"));
        feed.setTitle(localization.getTranslationPlain(msgPrefix + "title"));
        feed.setDescription(localization.getTranslationPlain(msgPrefix + "description"));
        feed.setCopyright(context.getWiki().getXWikiPreference("copyright", context));
        feed.setLink(context.getWiki().getExternalURL("xwiki:Main.WebHome", "view", context));
    }
}