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
015package org.apache.tapestry5.services.assets;
016
017import java.io.IOException;
018
019import org.apache.tapestry5.ioc.annotations.Primary;
020import 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)
032public 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}