001    // Copyright 2011 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    // http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry5.services.assets;
016    
017    import java.io.IOException;
018    
019    import org.apache.tapestry5.ioc.annotations.Primary;
020    import org.apache.tapestry5.ioc.annotations.UsesMappedConfiguration;
021    
022    /**
023     * Certain kinds of resources can be minimized: this primarily refers to JavaScript and CSS, both of which contain
024     * whitespace, comments and other features that can be reduced.
025     * <p>
026     * The service configuration maps a MIME content type (e.g., "text/javascript") to an appropriate implementation of this
027     * interface. The master service has the @{@link Primary} marker interface.
028     * 
029     * @since 5.3
030     */
031    @UsesMappedConfiguration(ResourceMinimizer.class)
032    public interface ResourceMinimizer
033    {
034        /**
035         * Checks the {@linkplain StreamableResource#getContentType() content type} of the resource and applies an
036         * appropriate minimization to it if possible.
037         * 
038         * @param resource
039         *            to minimize
040         * @return the same resource, or a minimized replacement for the resource
041         * @throws IOException
042         */
043        StreamableResource minimize(StreamableResource resource) throws IOException;
044    }