    001    package 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
    024    import org.apache.commons.logging.Log;
    025    import org.apache.commons.logging.LogFactory;
    026
    027    import org.apache.ecs.ConcreteElement;
    028
    029    import org.apache.turbine.modules.NavigationLoader;
    030
    031    import org.apache.turbine.services.template.TurbineTemplate;
    032
    033    import org.apache.turbine.util.RunData;
    034
    035    /**
    036     * Returns output of a Navigation module.  An instance of this is
    037     * placed in the WebMacro context by the WebMacroSiteLayout.  This
    038     * allows template authors to set the navigation template they'd like
    039     * to place in their templates.  Here's how it's used in a
    040     * template:
    041     *
    042     * <p><code>
    043     * $navigation.setTemplate("admin_navigation.wm")
    044     * </code>
    045     *
    046     * @author <a href="mbryson@mont.mindspring.com">Dave Bryson</a>
    047     * @version $Id: TemplateNavigation.java 615328 2008-01-25 20:25:05Z tv $
    048     */
    049    public class TemplateNavigation
    050    {
    051        /** Logging */
    052        private static Log log = LogFactory.getLog(TemplateNavigation.class);
    053
    054        /* The RunData object. */
    055        private RunData data;
    056
    057        /* The name of the navigation template. */
    058        private String template = null;
    059
    060        /**
    061         * Constructor
    062         *
    063         * @param data A Turbine RunData object.
    064         */
    065        public TemplateNavigation(RunData data)
    066        {
    067            this.data = data;
    068        }
    069
    070        /**
    071         * Set the template.
    072         *
    073         * @param template A String with the name of the navigation
    074         * template.
    075         * @return A TemplateNavigation (self).
    076         */
    077        public TemplateNavigation setTemplate(String template)
    078        {
    079            log.debug("setTemplate(" + template + ")");
    080            this.template = template;
    081            return this;
    082        }
    083
    084        /**
    085         * Builds the output of the navigation template.
    086         *
    087         * @return A String.
    088         */
    089        public String toString()
    090        {
    091            String module = null;
    092            String returnValue = null;
    093
    094            try
    095            {
    096                if (template == null)
    097                {
    098                    returnValue = "Navigation Template is null (Might be unset)";
    099                    throw new Exception(returnValue);
    100                }
    101
    102                data.getTemplateInfo().setNavigationTemplate(template);
    103                module = TurbineTemplate.getNavigationName(template);
    104
    105                if (module == null)
    106                {
    107                    returnValue = "Template Service returned null for Navigation Template " + template;
    108                    throw new Exception(returnValue);
    109                }
    110
    111                ConcreteElement results =
    112                        NavigationLoader.getInstance().eval(data, module);
    113                returnValue = results.toString();
    114            }
    115            catch (Exception e)
    116            {
    117                if (returnValue == null)
    118                {
    119                    returnValue = "Error processing navigation template: "
    120                            + template + ", using module: " + module;
    121                }
    122                log.error(returnValue, e);
    123            }
    124
    125            return returnValue;
    126        }
    127    }