org.debux.webmotion.server.handler.ExecutorInstanceCreatorHandler Maven / Gradle / Ivy

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/*
 * #%L
 * Toolkit :: Server
 * %%
 * Copyright (C) 2017 - 2024 Ultreia.io
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program.  If not, see
 * .
 * #L%
 */
package org.debux.webmotion.server.handler;

import org.debux.webmotion.server.WebMotionController;
import org.debux.webmotion.server.WebMotionHandler;
import org.debux.webmotion.server.call.Call;
import org.debux.webmotion.server.call.Executor;
import org.debux.webmotion.server.call.HttpContext;
import org.debux.webmotion.server.call.ServerContext;
import org.debux.webmotion.server.mapping.Config;
import org.debux.webmotion.server.mapping.Config.Scope;
import org.debux.webmotion.server.mapping.Mapping;
import org.debux.webmotion.server.tools.SingletonFactory;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

/**
 * Create instance contained in executor. Two modes are available, stateless mode
 * uses the same instance for each user request or stateful mode creates a
 * instance for each user request.
 *
 * @author julien
 */
public class ExecutorInstanceCreatorHandler extends AbstractHandler implements WebMotionHandler {

    @Override
    public void handle(Mapping mapping, Call call) {
        Executor executor = call.getCurrent();

        // You must test mode here to manage correctly extension, otherwise
        // you risk to have only the factory define in init method.
        SingletonFactory factory = getControllerFactory(mapping, call);
        Class actionClass = executor.getClazz();

        WebMotionController instance = factory.getInstance(actionClass);
        executor.setInstance(instance);
    }

    /**
     * Attribute name use to store controller factory in the session or the request
     */
    public static final String CONTROLLER_FACTORY_ATTRIBUTE = "org.debux.webmotion.server.CONTROLLER_FACTORY";

    /**
     * Search the controller factory from mode define in mapping.
     * TODO: 20120124 jru Move to other class, to delete the dependence between handler and the render.
     *
     * @param mapping mapping
     * @param call    call
     * @return controller factory
     */
    public static SingletonFactory getControllerFactory(Mapping mapping, Call call) {

        HttpContext context = call.getContext();
        Config config = mapping.getConfig();
        Scope scope = config.getControllerScope();
        switch (scope) {
            case REQUEST: {
                HttpServletRequest request = context.getRequest();
                @SuppressWarnings("unchecked") SingletonFactory factory = (SingletonFactory) request.getAttribute(CONTROLLER_FACTORY_ATTRIBUTE);
                if (factory == null) {
                    factory = new SingletonFactory<>();
                    request.setAttribute(CONTROLLER_FACTORY_ATTRIBUTE, factory);
                }
                return factory;
            }
            case SESSION: {
                HttpSession session = context.getSession();
                @SuppressWarnings("unchecked") SingletonFactory factory = (SingletonFactory) session.getAttribute(CONTROLLER_FACTORY_ATTRIBUTE);
                if (factory == null) {
                    factory = new SingletonFactory<>();
                    session.setAttribute(CONTROLLER_FACTORY_ATTRIBUTE, factory);
                }
                return factory;
            }
            case SINGLETON:
                ServerContext serverContext = context.getServerContext();
                return serverContext.getControllers();
        }
        throw new IllegalStateException("No factory found");
    }
}