ResourceTemplateLoader.java

/* 
 * (C) Copyright 2006-2011 Nuxeo SA (http://nuxeo.com/) and others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Contributors:
 *     bstefanescu
 *
 * $Id$
 */

package org.nuxeo.ecm.platform.rendering.fm;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.MalformedURLException;
import java.net.URL;

import org.nuxeo.ecm.platform.rendering.api.ResourceLocator;

import freemarker.cache.TemplateLoader;
import freemarker.cache.URLTemplateLoader;

/**
 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
 */
public class ResourceTemplateLoader implements TemplateLoader {

    protected ResourceLocator locator;

    protected final MyURLTemplateLoader urlLoader;

    protected final MyFileTemplateLoader fileLoader;

    public ResourceTemplateLoader(ResourceLocator locator) {
        this.locator = locator;
        urlLoader = new MyURLTemplateLoader();
        fileLoader = new MyFileTemplateLoader();
    }

    public void setLocator(ResourceLocator locator) {
        this.locator = locator;
    }

    public ResourceLocator getLocator() {
        return locator;
    }

    public void closeTemplateSource(Object templateSource) throws IOException {
        if (templateSource instanceof File) {
            fileLoader.closeTemplateSource(templateSource);
        } else if (templateSource instanceof URL) {
            urlLoader.closeTemplateSource(templateSource);
        }
    }

    public Object findTemplateSource(String name) throws IOException {
        if (name.startsWith("fs://")) { // hack for absolute paths - see
                                        // FreemarkerEngine#render()
            name = name.substring(5);
        } else if (name.contains(":/")) {
            return urlLoader.findTemplateSource(name);
        }
        Object obj = fileLoader.findTemplateSource(name);
        if (obj != null) {
            return obj;
        }
        return urlLoader.findTemplateSource(name);
    }

    public long getLastModified(Object templateSource) {
        if (templateSource instanceof File) {
            return fileLoader.getLastModified(templateSource);
        } else {
            return urlLoader.getLastModified(templateSource);
        }
    }

    public Reader getReader(Object templateSource, String encoding) throws IOException {
        if (templateSource instanceof File) {
            return fileLoader.getReader(templateSource, encoding);
        } else {
            return urlLoader.getReader(templateSource, encoding);
        }
    }

    class MyURLTemplateLoader extends URLTemplateLoader {
        @Override
        protected URL getURL(String arg0) {
            if (locator != null) {
                return locator.getResourceURL(arg0);
            }
            try {
                return new URL(arg0);
            } catch (MalformedURLException e) {
                return null;
            }
        }
    }

    class MyFileTemplateLoader implements TemplateLoader {
        public void closeTemplateSource(Object templateSource) throws IOException {
            // do nothing
        }

        public Object findTemplateSource(String name) throws IOException {
            if (locator != null) {
                File file = locator.getResourceFile(name);
                if (file != null) {
                    return file.getCanonicalFile();
                }
            }
            try {
                File file = new File(name).getCanonicalFile();
                if (file.isFile()) {
                    return file;
                }
            } catch (IOException e) {
                return null;
            }
            return null;
        }

        public long getLastModified(Object templateSource) {
            try {
                return ((File) templateSource).lastModified();
            } catch (ClassCastException e) {
                throw new IllegalArgumentException("templateSource is a: " + templateSource.getClass().getName());
            }
        }

        public Reader getReader(Object templateSource, String encoding) throws IOException {
            try {
                return new InputStreamReader(new FileInputStream((File) templateSource), encoding);
            } catch (ClassCastException e) {
                throw new IllegalArgumentException("templateSource is a: " + templateSource.getClass().getName());
            }
        }

    }

}