WikiTransformer.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.wiki;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.Writer;
import java.net.URL;
import java.util.Map;

import org.apache.commons.io.IOUtils;
import org.nuxeo.ecm.core.api.model.Property;
import org.nuxeo.ecm.platform.rendering.api.RenderingException;
import org.nuxeo.ecm.platform.rendering.fm.FreemarkerEngine;
import org.nuxeo.ecm.platform.rendering.fm.adapters.ComplexPropertyTemplate;
import org.nuxeo.ecm.platform.rendering.wiki.extensions.FreemarkerMacro;
import org.wikimodel.wem.WikiParserException;

import freemarker.core.Environment;
import freemarker.template.SimpleScalar;
import freemarker.template.TemplateDirectiveBody;
import freemarker.template.TemplateDirectiveModel;
import freemarker.template.TemplateException;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;

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

    protected final WikiSerializer serializer;

    public WikiTransformer() {
        this(new WikiSerializer());
    }

    public WikiTransformer(WikiSerializer serializer) {
        this.serializer = serializer;
        this.serializer.registerMacro(new FreemarkerMacro());
        // TODO implement and register a JEXL extension
    }

    public WikiSerializer getSerializer() {
        return serializer;
    }

    public void transform(Reader reader, Writer writer) throws RenderingException {
        try {
            serializer.serialize(reader, writer);
        } catch (IOException | WikiParserException e) {
            throw new RenderingException(e);
        }
    }

    public void transform(URL url, Writer writer) throws RenderingException {
        Reader reader = null;
        try {
            InputStream in = url.openStream();
            reader = new BufferedReader(new InputStreamReader(in));
            transform(reader, writer);
        } catch (IOException e) {
            throw new RenderingException(e);
        } finally {
            IOUtils.closeQuietly(reader);
        }
    }

    @Override
    @SuppressWarnings("rawtypes")
    public void execute(Environment env, Map params, TemplateModel[] loopVars, TemplateDirectiveBody body)
            throws TemplateException, IOException {

        // TODO: not used for now.
        String syntax = null;
        SimpleScalar scalar = (SimpleScalar) params.get("syntax");
        if (scalar != null) {
            syntax = scalar.getAsString();
        }

        scalar = (SimpleScalar) params.get("src");
        String src = null;
        if (scalar != null) {
            src = scalar.getAsString();
        }

        ComplexPropertyTemplate complex = (ComplexPropertyTemplate) params.get("property");
        Property property = null;
        if (complex != null) {
            property = (Property) complex.getAdaptedObject(null);
        }

        FreemarkerEngine engine = (FreemarkerEngine) env.getCustomAttribute(FreemarkerEngine.RENDERING_ENGINE_KEY);
        if (engine == null) {
            throw new TemplateModelException("Not in a nuxeo rendering context");
        }

        try {
            if (property != null) {
                // TODO XXX implement property support (with caching)
                throw new UnsupportedOperationException("Not Yet Implemented");
                // URL url = PropertyURL.getURL(ctxModel.getDocument(), property.getPath());
                // tr.transform(url, env.getOut(), ctxModel.getContext());
            } else if (src == null) {
                if (body == null) {
                    throw new TemplateModelException(
                            "Transform directive must have either a content either a valid 'src' attribute");
                }
                // render body to get back the result
                StringWriter writer = new StringWriter();
                body.render(writer);
                String content = writer.getBuffer().toString();
                transform(new StringReader(content), env.getOut());
            } else {
                if (src.contains(":/")) {
                    URL url = engine.getResourceLocator().getResourceURL(src);
                    if (url != null) {
                        transform(url, env.getOut());
                    } else {
                        throw new IllegalArgumentException("Cannot resolve the src attribute: " + src);
                    }
                } else {
                    File file = engine.getResourceLocator().getResourceFile(src);
                    if (file != null) {
                        transform(file.toURI().toURL(), env.getOut());
                    } else {
                        throw new IllegalArgumentException("Cannot resolve the src attribute: " + src);
                    }
                }
            }
        } catch (RenderingException e) {
            throw new TemplateException("Running wiki transformer failed", e, env);
        }
    }

}