001// Copyright 2006, 2008, 2009, 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.internal.services; 016 017import org.apache.tapestry5.ioc.Resource; 018import org.apache.tapestry5.services.InvalidationEventHub; 019import org.apache.tapestry5.services.ResourceDigestGenerator; 020 021/** 022 * Caches information about resources on the classpath. In addition, acts as an invalidation hub for any resources for 023 * which information is obtained (when any of the resources are changed, invalidation listeners are notified so they can 024 * clear their caches). 025 * <p/> 026 * Note that the name and role of this class changed (and diminished) quite a bit in Tapestry 5.3. It is now focused on 027 * determining which files require a digest, and which what the digests are for resources. 028 * <p/> 029 * Further, in 5.4, this service has been stripped down to an unused placeholder; it only present to prevent 030 * errors where modules have contributed a String extension to protected (even though the service is internal). As of 031 * 5.4, all assets have a built-in checksum in the URL directly (in 5.3 and earlier, the URL included the application 032 * version number). 033 * 034 * @deprecated Deprecated in 5.4 with no replacement; see release notes about classpath assets moving to /META-INF/assets/. 035 * To be removed in 5.5. 036 */ 037public interface ResourceDigestManager extends InvalidationEventHub 038{ 039 /** 040 * Returns true if the path requires that the client URL for the resource include a digest to validate that the 041 * client is authorized to access the resource. 042 * 043 * As of 5.4, simply returns false. 044 * 045 * @param resource 046 * @return true if digest is required for the resource 047 * @see ResourceDigestGenerator#requiresDigest(String) 048 */ 049 boolean requiresDigest(Resource resource); 050 051 /** 052 * Returns the digest for the given path. 053 * <p/> 054 * As of 5.4, simple returns null. 055 * 056 * @param resource 057 * @return the digest, or null if the resource does not exist 058 */ 059 String getDigest(Resource resource); 060}