    001package org.apache.turbine.util.template;
    002
    003
    004/*
    005 * Licensed to the Apache Software Foundation (ASF) under one
    006 * or more contributor license agreements.  See the NOTICE file
    007 * distributed with this work for additional information
    008 * regarding copyright ownership.  The ASF licenses this file
    009 * to you under the Apache License, Version 2.0 (the
    010 * "License"); you may not use this file except in compliance
    011 * with the License.  You may obtain a copy of the License at
    012 *
    013 *   http://www.apache.org/licenses/LICENSE-2.0
    014 *
    015 * Unless required by applicable law or agreed to in writing,
    016 * software distributed under the License is distributed on an
    017 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    018 * KIND, either express or implied.  See the License for the
    019 * specific language governing permissions and limitations
    020 * under the License.
    021 */
    022
    023
    024import org.apache.commons.logging.Log;
    025import org.apache.commons.logging.LogFactory;
    026import org.apache.turbine.modules.Screen;
    027import org.apache.turbine.modules.ScreenLoader;
    028import org.apache.turbine.services.TurbineServices;
    029import org.apache.turbine.services.assemblerbroker.AssemblerBrokerService;
    030import org.apache.turbine.util.RunData;
    031
    032/**
    033 * Returns output of a Screen module.  An instance of this is
    034 * placed in the Velocity context by the VelocityDirectLayout.  This
    035 * allows the screen to be executed only at rendering.
    036 * Here's how it's used in a template:
    037 *
    038 * <p>
    039 * <code>
    040 * $screen_placeholder
    041 * </code>
    042 * <p>
    043 * <code>
    044 * $screen_placeholder.setScreen("Test")
    045 * </code>
    046 * </p>
    047 *
    048 * @author <a href="raphael@apache.org">Raphaël Luta</a>
    049 * @version $Id: TemplateScreen.java 1723699 2016-01-08 11:29:21Z tv $
    050 */
    051public class TemplateScreen
    052{
    053    /** Logging */
    054    private static Log log = LogFactory.getLog(TemplateScreen.class);
    055
    056    /* The RunData object. */
    057    private final RunData data;
    058
    059    /* The name of the screen template. */
    060    private String screen;
    061
    062    private final ScreenLoader screenLoader;
    063
    064    /**
    065     * Constructor
    066     *
    067     * @param data A Turbine RunData object.
    068     */
    069    public TemplateScreen(RunData data)
    070    {
    071        this.data = data;
    072        this.screen = data.getScreen();
    073        AssemblerBrokerService abs = (AssemblerBrokerService)TurbineServices.getInstance()
    074            .getService(AssemblerBrokerService.SERVICE_NAME);
    075        this.screenLoader = (ScreenLoader)abs.getLoader(Screen.class);
    076    }
    077
    078    /**
    079     * Set the screen.
    080     *
    081     * @param screen A String with the name of the screen module
    082     * @return A TemplateScreen (self).
    083     */
    084    public TemplateScreen setScreen(String screen)
    085    {
    086        this.screen = screen;
    087        return this;
    088    }
    089
    090    /**
    091     * Builds the output of the navigation template.
    092     *
    093     * @return A String.
    094     */
    095    @Override
    096    public String toString()
    097    {
    098        String returnValue = "";
    099
    100        try
    101        {
    102            String results = screenLoader.eval(data, this.screen);
    103
    104            if (results != null)
    105            {
    106                returnValue = results;
    107            }
    108        }
    109        catch (Exception e)
    110        {
    111            log.error(e);
    112        }
    113
    114        return returnValue;
    115    }
    116}