org.sakaiproject.tool.gradebook.ui.ConfigurationBean.java Source code

Introduction

Here is the source code for org.sakaiproject.tool.gradebook.ui.ConfigurationBean.java

Source

/**********************************************************************************
*
* $Id$
*
***********************************************************************************
*
 * Copyright (c) 2007, 2008 The Sakai Foundation
 *
 * Licensed under the Educational Community 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.opensource.org/licenses/ECL-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 org.sakaiproject.tool.gradebook.ui;

import java.util.Map;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.sakaiproject.component.api.ServerConfigurationService;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

/**
 * Provides a way to override UI bean definitions from the Sakai component
 * framework while still visibly injecting them in UI configuration files.
 * 
 * (If our UI logic was based on Spring beans rather than JSF backing beans,
 * there might be a more straightforward way to deliver this capability.)
 */
public class ConfigurationBean implements ApplicationContextAware {
    private static final Log log = LogFactory.getLog(ConfigurationBean.class);

    private ApplicationContext applicationContext;

    private Map<String, Object> pluginDefaults;
    private ServerConfigurationService serverConfigurationService;

    /**
     * @param name
     * @return the bean configured to match the given plug-in key, or null if none were found
     */
    public Object getPlugin(String key) {
        Object target = null;
        if (log.isDebugEnabled())
            log.debug("key=" + key + ", serverConfigurationService=" + serverConfigurationService + ", default="
                    + pluginDefaults.get(key));
        if (serverConfigurationService != null) {
            // As of Sakai 2.4, the framework's configuration service
            // returns the empty string instead of null if a property isn't found.
            target = StringUtils.stripToNull(serverConfigurationService.getString(key));
        }
        if (target == null) {
            target = pluginDefaults.get(key);
        }
        if (target != null) {
            if (target instanceof String) {
                // Assume that we got a bean name instead of the
                // bean itself.
                target = applicationContext.getBean((String) target);
            }
        }
        if (log.isDebugEnabled())
            log.debug("for " + key + " returning " + target);
        return target;
    }

    public String getConfig(String name, String defaultValue) {
        String val = defaultValue;
        if (serverConfigurationService != null) {
            val = serverConfigurationService.getString(name, defaultValue);
        }
        return val;
    }

    public boolean getBooleanConfig(String name, boolean defaultValue) {
        boolean val = defaultValue;
        if (serverConfigurationService != null) {
            val = serverConfigurationService.getBoolean(name, defaultValue);
        }
        return val;
    }

    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }

    public void setPluginDefaults(Map<String, Object> pluginDefaults) {
        this.pluginDefaults = pluginDefaults;
    }

    /**
     * If this method is never called (as in the case of standalone builds), the
     * default map of property values will be used. 
     * @param serverConfigurationService
     */
    public void setServerConfigurationService(ServerConfigurationService serverConfigurationService) {
        this.serverConfigurationService = serverConfigurationService;
    }
}