001// Copyright 2013 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.webresources;
016
017/**
018 * Controls caching for {@link ResourceTransformerFactory} in <em>development mode</em>. In production mode, caching at this
019 * level is not needed, because artifacts are also cached later in the pipeline. This caching is all about avoid unwanted
020 */
021public enum CacheMode
022{
023    /**
024     * Cache the content on the file system, in the directory defined by {@link org.apache.tapestry5.webresources.WebResourcesSymbols#CACHE_DIR}.
025     * This allows compilation to be avoided even after a restart, as long as the source file has not changed. This only works
026     * for compilations that operate on a single file (such as CoffeeScript, but not Less, which has an {@code @import} statement).
027     */
028    SINGLE_FILE,
029
030    /**
031     * The source may be multiple files (e.g., Less). Cache in memory, and invalidate the cache if any of the multiple
032     * file's content changes.
033     */
034    MULTIPLE_FILE,
035
036    /**
037     * Do no caching. This is appropriate for extremely cheap compilers.
038     */
039    NONE;
040}