org.odlabs.wiquery.core.WiQueryInitializer.java Source code

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Here is the source code for org.odlabs.wiquery.core.WiQueryInitializer.java

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/*
 * Copyright (c) 2009 WiQuery team
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package org.odlabs.wiquery.core;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Iterator;
import java.util.Properties;

import org.apache.wicket.Application;
import org.apache.wicket.IInitializer;
import org.apache.wicket.MetaDataKey;
import org.apache.wicket.WicketRuntimeException;
import org.apache.wicket.util.io.IOUtils;
import org.apache.wicket.util.lang.WicketObjects;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * $Id: WiQueryInitializer.java 721 2011-03-09 08:32:12Z hielke.hoeve@gmail.com $
 * <p>
 * {@link IInitializer} to retrieve settings for wiQuery
 * </p>
 * 
 * @author Julien Roche
 * @since 1.1
 */
public class WiQueryInitializer implements IInitializer {
    public static final MetaDataKey<WiQuerySettings> WIQUERY_INSTANCE_KEY = new MetaDataKey<WiQuerySettings>() {
        private static final long serialVersionUID = 1L;
    };

    private static final Logger LOGGER = LoggerFactory.getLogger(WiQueryInitializer.class);

    public void init(Application application) {
        Application.get().getComponentInstantiationListeners().add(new WiQueryPluginInstantiationListener());

        // check for WiQuerySettings on the application
        WiQuerySettings settings = application.getMetaData(WIQUERY_INSTANCE_KEY);

        // create new one when application has none
        if (settings == null) {
            settings = new WiQuerySettings();
            // apply IWiQuerySettings to the applications metadata
            application.setMetaData(WIQUERY_INSTANCE_KEY, settings);
            // IWiQueryInitializer treatments
            retrieveAndCallInitializers(application, settings);
        } else {
            LOGGER.info("application already hasWiQuerySettings");
        }
    }

    public void destroy(Application application) {
        // noop
    }

    /**
     * <p>
     * Method finding and calling the {@link IWiQueryInitializer}.
     * </p>
     * 
     * This will find find wiquery.properties files in the following order:
     * <ul>
     * <li>wiquery jar/bundle</li>
     * <li>
     * user's application jar/bundle</li>
     * <li>
     * all other resources</li>
     * </ul>
     * 
     */
    private void retrieveAndCallInitializers(Application application, WiQuerySettings wiQuerySettings) {

        // Load any wiquery properties files we can find
        try {
            // Load properties files used by all libraries
            final Iterator<URL> resources = application.getApplicationSettings().getClassResolver()
                    .getResources("wiquery.properties");
            while (resources.hasNext()) {
                InputStream in = null;
                try {
                    final URL url = resources.next();
                    final Properties properties = new Properties();
                    in = url.openStream();
                    properties.load(in);
                    load(application, wiQuerySettings, properties);
                } finally {
                    IOUtils.close(in);
                }
            }
        } catch (IOException e) {
            throw new WicketRuntimeException("Unable to load initializers file", e);
        }

        // now call any initializers we read
        callInitializers(application, wiQuerySettings);
    }

    /**
     * @param wiQuerySettings
     * @param properties
     *            Properties map with names of any library initializers in it
     */
    private void load(Application application, WiQuerySettings wiQuerySettings, Properties properties) {
        addInitializer(wiQuerySettings, properties.getProperty("initializer"));
        addInitializer(wiQuerySettings, properties.getProperty(application.getName() + "-initializer"));
    }

    /**
     * Construct and add initializer from the provided class name.
     * 
     * @param className
     */
    private void addInitializer(WiQuerySettings wiQuerySettings, String className) {
        IWiQueryInitializer initializer = (IWiQueryInitializer) WicketObjects.newInstance(className);
        if (initializer != null) {
            wiQuerySettings.addInitializer(initializer);
        }
    }

    /**
     * Iterate initializers list, calling any instances found in it.
     * 
     * @param wiQuerySettings
     */
    private void callInitializers(Application application, WiQuerySettings wiQuerySettings) {
        for (IWiQueryInitializer initializer : wiQuerySettings.getInitializers()) {
            LOGGER.info("[" + application.getName() + "] init: " + initializer);
            initializer.init(application, wiQuerySettings);
        }
    }
}