001// Copyright 2006, 2007, 2008, 2009, 2010 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.Asset;
018import org.apache.tapestry5.ioc.Resource;
019import org.apache.tapestry5.services.AssetFactory;
020import org.apache.tapestry5.services.AssetPathConverter;
021import org.apache.tapestry5.services.Context;
022import org.apache.tapestry5.services.assets.AssetPathConstructor;
023
024/**
025 * Implementation of {@link AssetFactory} for assets that are part of the web application context.
026 *
027 * @see org.apache.tapestry5.internal.services.ContextResource
028 */
029public class ContextAssetFactory implements AssetFactory
030{
031    private final AssetPathConstructor assetPathConstructor;
032
033    private final Resource rootResource;
034
035    private final AssetPathConverter converter;
036
037    private final boolean invariant;
038
039    public ContextAssetFactory(AssetPathConstructor assetPathConstructor, Context context,
040
041                               AssetPathConverter converter)
042    {
043        this.assetPathConstructor = assetPathConstructor;
044        this.converter = converter;
045
046        rootResource = new ContextResource(context, "/");
047        invariant = this.converter.isInvariant();
048    }
049
050    public Asset createAsset(Resource resource)
051    {
052        String defaultPath = assetPathConstructor.constructAssetPath(RequestConstants.CONTEXT_FOLDER, resource.getPath());
053
054        if (invariant)
055        {
056            return createInvariantAsset(resource, defaultPath);
057        }
058
059        return createVariantAsset(resource, defaultPath);
060    }
061
062    private Asset createInvariantAsset(final Resource resource, final String defaultPath)
063    {
064        return new AbstractAsset(true)
065        {
066            private String clientURL;
067
068            public Resource getResource()
069            {
070                return resource;
071            }
072
073            public String toClientURL()
074            {
075                if (clientURL == null)
076                {
077                    clientURL = converter.convertAssetPath(defaultPath);
078                }
079
080                return clientURL;
081            }
082        };
083    }
084
085    private Asset createVariantAsset(final Resource resource, final String defaultPath)
086    {
087        return new AbstractAsset(false)
088        {
089            public Resource getResource()
090            {
091                return resource;
092            }
093
094            public String toClientURL()
095            {
096                return converter.convertAssetPath(defaultPath);
097            }
098        };
099    }
100
101    /**
102     * Returns the root {@link org.apache.tapestry5.internal.services.ContextResource}.
103     */
104    public Resource getRootResource()
105    {
106        return rootResource;
107    }
108}