001/*
002 * This library is part of OpenCms -
003 * the Open Source Content Management System
004 *
005 * Copyright (C) Alkacon Software (http://www.alkacon.com)
006 *
007 * This library is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * This library is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015 * Lesser General Public License for more details.
016 *
017 * For further information about Alkacon Software, please see the
018 * company website: http://www.alkacon.com
019 *
020 * For further information about OpenCms, please see the
021 * project website: http://www.opencms.org
022 *
023 * You should have received a copy of the GNU Lesser General Public
024 * License along with this library; if not, write to the Free Software
025 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
026 */
027
028package org.opencms.loader;
029
030import org.opencms.file.CmsObject;
031import org.opencms.file.CmsResource;
032import org.opencms.main.CmsException;
033
034import java.util.Map;
035
036import javax.servlet.http.HttpServletRequest;
037
038/**
039 * Interface for template context providers.<p>
040 *
041 * Implementations of this class are used to dynamically determine a template used for rendering
042 * a page at runtime, e.g. there could be one template for desktop browsers and another for mobile
043 * browsers.
044 *
045 * It is possible to override the template using a cookie containing the name of the template context
046 * which should be used as a value. The cookie name is determined by the template context provider.<p>
047 */
048public interface I_CmsTemplateContextProvider {
049
050    /**
051     * Gets a map of all template contexts, with the template context names as keys.<p>
052     *
053     * @return the map of template context providers
054     */
055    Map<String, CmsTemplateContext> getAllContexts();
056
057    /**
058     * Returns the style sheet to be used for the editor.<p>
059     *
060     * @param cms the current CMS context
061     * @param editedResourcePath the path of the edited resource
062     *
063     * @return the path of the style sheet to be used for the resource
064     */
065    String getEditorStyleSheet(CmsObject cms, String editedResourcePath);
066
067    /**
068     * Gets the name of the cookie which should be used for overriding the template context.<p>
069     *
070     * @return the name of the cookie used for overriding the template context
071     */
072    String getOverrideCookieName();
073
074    /**
075     * Determines the template context from the current CMS context, request, and resource.<p>
076     *
077     * @param cms the CMS context
078     * @param request the current request
079     * @param resource the resource being rendered
080     *
081     * @return the current template context
082     */
083    CmsTemplateContext getTemplateContext(CmsObject cms, HttpServletRequest request, CmsResource resource);
084
085    /**
086     * Initializes the context provider using a CMS object.<p>
087     *
088     * @param cms the current CMS context
089     * @param config the template context provider configuration
090     */
091    void initialize(CmsObject cms, String config);
092
093    /**
094     * Gets the value which should be used instead of a property which was read from the template resource.<p>
095     *
096     * This is needed because before template context providers, it was common to store template-specific configuration in
097     * a property on the template JSP. Since template context providers make the result ambiguous, this method is intended
098     * as a replacement.<p>
099     *
100     * @param cms the CMS context to use
101     * @param propertyName the name of the property
102     * @param fallbackValue the value to return if no value is found or an error occurs
103     *
104     * @return the common property value
105     *
106     * @throws CmsException if something goes wrong
107     */
108    String readCommonProperty(CmsObject cms, String propertyName, String fallbackValue) throws CmsException;
109
110}