com.baldmountain.depot.DepotHandlebarsTemplateEngine.java Source code

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Here is the source code for com.baldmountain.depot.DepotHandlebarsTemplateEngine.java

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/*
 * Copyright 2014 Red Hat, Inc.
 *
 *  All rights reserved. This program and the accompanying materials
 *  are made available under the terms of the Eclipse Public License v1.0
 *  and Apache License v2.0 which accompanies this distribution.
 *
 *  The Eclipse Public License is available at
 *  http://www.eclipse.org/legal/epl-v10.html
 *
 *  The Apache License v2.0 is available at
 *  http://www.opensource.org/licenses/apache2.0.php
 *
 *  You may elect to redistribute this code under either of these licenses.
 */

package com.baldmountain.depot;

import com.github.jknack.handlebars.Handlebars;
import com.github.jknack.handlebars.Template;
import com.github.jknack.handlebars.io.TemplateLoader;
import com.github.jknack.handlebars.io.TemplateSource;
import io.vertx.core.*;
import io.vertx.core.buffer.Buffer;
import io.vertx.ext.apex.RoutingContext;
import io.vertx.ext.apex.impl.Utils;
import io.vertx.ext.apex.templ.HandlebarsTemplateEngine;
import io.vertx.ext.apex.templ.impl.CachingTemplateEngine;

import java.io.IOException;

/**
 * @author <a href="http://pmlopes@gmail.com">Paulo Lopes</a>
 * @author <a href="http://tfox.org">Tim Fox</a>
 */
public class DepotHandlebarsTemplateEngine extends CachingTemplateEngine<Template>
        implements HandlebarsTemplateEngine {

    private final Handlebars handlebars;
    private final Loader loader = new Loader();

    static DepotHandlebarsTemplateEngine create() {
        return new DepotHandlebarsTemplateEngine();
    }

    public DepotHandlebarsTemplateEngine() {
        super(HandlebarsTemplateEngine.DEFAULT_TEMPLATE_EXTENSION, HandlebarsTemplateEngine.DEFAULT_MAX_CACHE_SIZE);
        handlebars = new Handlebars(loader);
    }

    @Override
    public DepotHandlebarsTemplateEngine setExtension(String extension) {
        doSetExtension(extension);
        return this;
    }

    @Override
    public DepotHandlebarsTemplateEngine setMaxCacheSize(int maxCacheSize) {
        this.cache.setMaxSize(maxCacheSize);
        return null;
    }

    @Override
    public void render(RoutingContext context, String templateFileName, Handler<AsyncResult<Buffer>> handler) {
        try {
            Template template = cache.get(templateFileName);
            if (template == null) {
                synchronized (this) {
                    loader.setVertx(context.vertx());
                    template = handlebars.compile(templateFileName);
                    cache.put(templateFileName, template);
                }
            }
            handler.handle(Future.succeededFuture(Buffer.buffer(template.apply(context.data()))));
        } catch (Exception ex) {
            handler.handle(Future.failedFuture(ex));
        }
    }

    public Handlebars getHandlebars() {
        return handlebars;
    }

    private class Loader implements TemplateLoader {

        private Vertx vertx;

        void setVertx(Vertx vertx) {
            this.vertx = vertx;
        }

        @Override
        public TemplateSource sourceAt(String location) throws IOException {

            String loc = adjustLocation(location);
            String templ = Utils.readFileToString(vertx, loc);

            if (templ == null) {
                throw new IllegalArgumentException("Cannot find resource " + loc);
            }

            long lastMod = System.currentTimeMillis();

            return new TemplateSource() {
                @Override
                public String content() throws IOException {
                    // load from the file system
                    return templ;
                }

                @Override
                public String filename() {
                    return loc;
                }

                @Override
                public long lastModified() {
                    return lastMod;
                }
            };
        }

        @Override
        public String resolve(String location) {
            return location;
        }

        @Override
        public String getPrefix() {
            return null;
        }

        @Override
        public String getSuffix() {
            return extension;
        }

        @Override
        public void setPrefix(String prefix) {

        }

        @Override
        public void setSuffix(String suffix) {
            extension = suffix;
        }
    }
}