burrito.Configurator.java Source code

Introduction

Here is the source code for burrito.Configurator.java

Source

/**
 * Copyright 2011 Henric Persson (henric.persson@gmail.com)
 * 
 * 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 burrito;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

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

import org.apache.commons.lang.RandomStringUtils;

import siena.Model;
import taco.Protector;
import burrito.links.Linkable;
import burrito.services.DatastoreSearchManager;
import burrito.services.SearchManager;
import burrito.sitelet.Sitelet;
import burrito.util.EntityUtil;

import com.google.appengine.api.users.UserService;
import com.google.appengine.api.users.UserServiceFactory;

public abstract class Configurator implements ServletContextListener {

    public static List<Class<? extends Model>> crudables = Collections
            .synchronizedList(new ArrayList<Class<? extends Model>>());
    public static List<Class<? extends Sitelet>> sitelets = Collections
            .synchronizedList(new ArrayList<Class<? extends Sitelet>>());
    public static List<Class<? extends burrito.links.Linkable>> linkables = Collections
            .synchronizedList(new ArrayList<Class<? extends Linkable>>());
    public static boolean MAY_RETIRE_SITELETS = false;
    public static Class<? extends SearchManager> SEARCH_MANAGER_TYPE = DatastoreSearchManager.class;

    private static final String DEV_MODE_CONFIGURATION_SUFFIX = "-DEV-" + RandomStringUtils.randomAlphabetic(4);
    private static String SITE_IDENTIFIER;
    private static BroadcastSettings BROADCAST_SETTINGS;
    private static Protector ADMIN_PROTECTOR;

    /**
     * Make an entity appear in the automated CRUD admin area.
     * 
     * @param m
     */
    public void addCrudable(Class<? extends Model> m) {
        if (!EntityUtil.getParentClasses(m).contains(BurritoModel.class)) {
            System.err.println("WARNING:\nThe crudable class " + m.getName() + " does not extend "
                    + BurritoModel.class.getName()
                    + ". This means that you will have to update search indexes on save/delete yourself.\n\n");
        }
        crudables.add(m);
    }

    public void addLinkable(Class<? extends Linkable> link) {
        linkables.add(link);
    }

    public void addSitelet(Class<? extends Sitelet> sitelet) {
        sitelets.add(sitelet);
    }

    @Override
    public void contextDestroyed(ServletContextEvent arg0) {
        // do nothing
    }

    /**
     * Initializes the configurator
     */
    protected abstract void init();

    /**
     * Return a unique identifier for your site. This could for example be the
     * id for your GAE app. It is important that this identifier is unique among
     * all sites connecting to the same feed server. Otherwise you can end up
     * with messages being broadcasted to the wrong site.
     * 
     * @return
     */
    protected abstract String configureSiteIdentifier();

    /**
     * Return a "password" string that will be used when broadcasting messages
     * via the feeds server. All broadcasts will contain this secret and the
     * feeds server will only let through those that provide a correct secret.
     * 
     * @return
     */
    protected abstract BroadcastSettings configureBroadcastSettings();

    /**
     * Defines whether sitelets should go into retirement mode if they haven't
     * been displayed for a while (24 h). In retirement mode, sitelets need to be 
     * displayed in a page for it to be scheduled for refresh.   
     * 
     * default is false 
     */
    protected boolean mayRetireSitelets() {
        return false;
    }

    /**
     * Configures the admin protector. This protector is used to decide whether
     * the current request is being made from an admin or not.
     * 
     * @return
     */
    protected Protector configureAdminProtector() {
        return new Protector() {

            @Override
            public boolean allow(HttpServletRequest request) {
                UserService service = UserServiceFactory.getUserService();
                if (!service.isUserLoggedIn()) {
                    return false;
                }
                return service.isUserAdmin();
            }
        };
    }

    /**
     * Gets the site identifier configured for this Burrito instance.
     * 
     * @return
     */
    public static String getSiteIdentifier() {
        return SITE_IDENTIFIER;
    }

    /**
     * Gets the broadcast settings
     * 
     * @return
     */
    public static BroadcastSettings getBroadcastSettings() {
        return BROADCAST_SETTINGS;
    }

    /**
     * Gets an admin protector
     * 
     * @return
     */
    public static Protector getAdminProtector() {
        return ADMIN_PROTECTOR;
    }

    @Override
    public void contextInitialized(ServletContextEvent ctx) {
        if (isDevMode(ctx.getServletContext())) {
            SITE_IDENTIFIER = configureSiteIdentifier() + DEV_MODE_CONFIGURATION_SUFFIX;
        } else {
            SITE_IDENTIFIER = configureSiteIdentifier();
        }
        BROADCAST_SETTINGS = configureBroadcastSettings();
        ADMIN_PROTECTOR = configureAdminProtector();
        MAY_RETIRE_SITELETS = mayRetireSitelets();

        init();
    }

    private boolean isDevMode(ServletContext context) {
        String serverInfo = context.getServerInfo();
        /*
         * ServerInfo will look something like "Google App Engine Development/x.x.x" when running in
         * the development server. In production mode it will look like "Google App Engine/x.x.x"
         */
        return serverInfo.contains("Development");
    }

}