001// Licensed under the Apache License, Version 2.0 (the "License");
002// you may not use this file except in compliance with the License.
003// You may obtain a copy of the License at
004//
005// http://www.apache.org/licenses/LICENSE-2.0
006//
007// Unless required by applicable law or agreed to in writing, software
008// distributed under the License is distributed on an "AS IS" BASIS,
009// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
010// See the License for the specific language governing permissions and
011// limitations under the License.
012
013package org.apache.tapestry5.internal.webresources;
014
015import org.apache.commons.io.IOUtils;
016import org.apache.tapestry5.ContentType;
017import org.apache.tapestry5.annotations.Path;
018import org.apache.tapestry5.internal.InternalConstants;
019import org.apache.tapestry5.ioc.OperationTracker;
020import org.apache.tapestry5.ioc.Resource;
021import org.apache.tapestry5.ioc.internal.util.CollectionFactory;
022import org.apache.tapestry5.ioc.internal.util.InternalUtils;
023import org.apache.tapestry5.services.assets.ResourceDependencies;
024import org.apache.tapestry5.services.assets.ResourceTransformer;
025import org.mozilla.javascript.NativeObject;
026
027import java.io.IOException;
028import java.io.InputStream;
029import java.nio.charset.Charset;
030import java.util.List;
031
032public class CoffeeScriptCompiler implements ResourceTransformer
033{
034    private final static Charset UTF8 = Charset.forName("utf-8");
035
036    private final RhinoExecutorPool executorPool;
037
038    @Override
039    public ContentType getTransformedContentType()
040    {
041        return InternalConstants.JAVASCRIPT_CONTENT_TYPE;
042    }
043
044    public CoffeeScriptCompiler(@Path("classpath:org/apache/tapestry5/webresources/internal/coffee-script.js")
045                                Resource mainCompiler,
046                                @Path("classpath:org/apache/tapestry5/webresources/internal/invoke-coffeescript.js")
047                                Resource shim,
048                                OperationTracker tracker)
049    {
050
051        executorPool = new RhinoExecutorPool(tracker, toList(mainCompiler, shim));
052    }
053
054    private List<Resource> toList(Resource... resources)
055    {
056        List<Resource> list = CollectionFactory.newList();
057
058        for (Resource r : resources)
059        {
060            list.add(r);
061        }
062
063        return list;
064    }
065
066
067    private static String getString(NativeObject object, String key)
068    {
069        return object.get(key).toString();
070    }
071
072
073    @Override
074    public InputStream transform(Resource source, ResourceDependencies dependencies) throws IOException
075    {
076        InputStream is = null;
077        String content;
078
079        try
080        {
081            is = source.openStream();
082            content = IOUtils.toString(is, UTF8);
083        } finally
084        {
085            InternalUtils.close(is);
086        }
087
088        RhinoExecutor executor = executorPool.get();
089
090        try
091        {
092
093            NativeObject result = (NativeObject) executor.invokeFunction("compileCoffeeScriptSource", content, source.toString());
094
095            if (result.containsKey("exception"))
096            {
097                throw new RuntimeException(getString(result, "exception"));
098            }
099
100            return IOUtils.toInputStream(getString(result, "output"), UTF8);
101
102        } finally
103        {
104            executor.discard();
105        }
106
107
108    }
109}