com.jetdrone.vertx.yoke.engine.HandlebarsEngine Maven / Gradle / Ivy
/*
* Copyright 2011-2012 the original author or authors.
*
* 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.
*/
package com.jetdrone.vertx.yoke.engine;
import com.github.jknack.handlebars.Handlebars;
import com.github.jknack.handlebars.Helper;
import com.github.jknack.handlebars.Template;
import com.github.jknack.handlebars.io.TemplateLoader;
import com.github.jknack.handlebars.io.TemplateSource;
import com.jetdrone.vertx.yoke.core.YokeAsyncResult;
import com.jetdrone.vertx.yoke.engine.AbstractEngineSync;
import org.vertx.java.core.AsyncResult;
import org.vertx.java.core.Handler;
import org.vertx.java.core.buffer.Buffer;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Map;
public class HandlebarsEngine extends AbstractEngineSync {
private final Handlebars handlebars;
private final String prefix;
private final String extension = ".hbs";
public HandlebarsEngine(final String views) {
super(null);
if ("".equals(views)) {
prefix = views;
} else {
prefix = views.endsWith("/") ? views : views + "/";
}
handlebars = new Handlebars(new TemplateLoader() {
@Override
public TemplateSource sourceAt(final String location) throws IOException {
// load from the file system
final String buffer = read(resolve(location));
if (buffer == null) {
throw new FileNotFoundException(location);
}
return new TemplateSource() {
@Override
public String content() throws IOException {
// load from the file system
return buffer;
}
@Override
public String filename() {
return location;
}
@Override
public long lastModified() {
return HandlebarsEngine.this.lastModified(location);
}
};
}
@Override
public String resolve(String location) {
return HandlebarsEngine.this.resolve(location);
}
@Override
public String getPrefix() {
return prefix;
}
@Override
public String getSuffix() {
return extension;
}
});
}
@Override
public String extension() {
return extension;
}
private String resolve(String location) {
String normalized = normalize(location);
if (normalized.endsWith(extension)) {
return prefix + normalized;
}
return prefix + normalized + extension;
}
private String normalize(final String location) {
if (location.startsWith("/")) {
return location.substring(1);
}
return location;
}
@Override
public void render(final String filename, final Map context, final Handler> next) {
try {
Template template = getTemplateFromCache(resolve(filename));
if (template == null) {
// real compile
template = handlebars.compile(filename);
putTemplateToCache(resolve(filename), template);
}
next.handle(new YokeAsyncResult<>(new Buffer(template.apply(context))));
} catch (Exception ex) {
ex.printStackTrace();
next.handle(new YokeAsyncResult(ex));
}
}
public void render(final String filename, final String layoutFilename, final Map context, final Handler> handler) {
handler.handle(new YokeAsyncResult(new UnsupportedOperationException()));
}
public void registerHelper(String name, Helper helper) {
handlebars.registerHelper(name, helper);
}
}