tapestry-tutorial1/src/main/java/org/apache/tapestry5/tutorial/services/AppModule.java

// Copyright 2007 The Apache Software Foundation
//
// Licensed under the Apache 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.apache.org/licenses/LICENSE-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.apache.tapestry5.tutorial.services;

import org.apache.tapestry5.SymbolConstants;
import org.apache.tapestry5.ioc.MappedConfiguration;
import org.apache.tapestry5.ioc.OrderedConfiguration;
import org.apache.tapestry5.ioc.annotations.Marker;
import org.apache.tapestry5.services.Request;
import org.apache.tapestry5.services.RequestFilter;
import org.apache.tapestry5.services.RequestHandler;
import org.apache.tapestry5.services.Response;
import org.slf4j.Logger;

import java.io.IOException;

/**
 * This module is automatically included as part of the Tapestry IoC Registry, it's a good place to configure and extend
 * Tapestry, or to place your own services.
 */
@Marker(Local.class)
public class AppModule
{
    public static void contributeApplicationDefaults(
            MappedConfiguration<String, String> configuration)
    {
        // Contributions to ApplicationDefaults will override any contributions to
        // FactoryDefaults (with the same key). Here we're restricting the supported
        // locales to just "en" (English). As you add localised message catalogs and other assets,
        // you can extend this list of locales (it's a comma seperated series of locale names;
        // the first locale name is the default when there's no reasonable match).

        configuration.add(SymbolConstants.SUPPORTED_LOCALES, "en");
        configuration.add(SymbolConstants.PRODUCTION_MODE, "false");
    }

    /**
     * This is a service definition, the service will be named TimingFilter. The interface, RequestFilter, is used
     * within the RequestHandler service pipeline, which is built from the RequestHandler service configuration.
     * Tapestry IoC is responsible for passing in an appropriate Log instance. Requests for static resources are handled
     * at a higher level, so this filter will only be invoked for Tapestry related requests.
     */
    public RequestFilter buildTimingFilter(final Logger logger)
    {
        return new RequestFilter()
        {
            public boolean service(Request request, Response response, RequestHandler handler)
                    throws IOException
            {
                long startTime = System.currentTimeMillis();

                try
                {
                    // The reponsibility of a filter is to invoke the corresponding method
                    // in the handler. When you chain multiple filters together, each filter
                    // received a handler that is a bridge to the next filter.

                    return handler.service(request, response);
                }
                finally
                {
                    long elapsed = System.currentTimeMillis() - startTime;

                    logger.info(String.format("Request time: %d ms", elapsed));
                }
            }
        };
    }

    /**
     * This is a contribution to the RequestHandler service configuration. This is how we extend Tapestry using the
     * timing filter. A common use for this kind of filter is transaction management or security.
     */
    public void contributeRequestHandler(OrderedConfiguration<RequestFilter> configuration,

                                         @Local
                                         RequestFilter filter)
    {
        // Each contribution to an ordered configuration has a name, When necessary, you may
        // set constraints to precisely control the invocation order of the contributed filter
        // within the pipeline.

        configuration.add("Timing", filter);
    }
}