All Downloads are FREE. Search and download functionalities are using the official Maven repository.

com.github.jknack.handlebars.helper.LookupHelper Maven / Gradle / Ivy

/**
 * Copyright (c) 2012-2015 Edgar Espina
 *
 * This file is part of Handlebars.java.
 *
 * 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.github.jknack.handlebars.helper;

import java.io.IOException;

import com.github.jknack.handlebars.Context;
import com.github.jknack.handlebars.Helper;
import com.github.jknack.handlebars.Options;

/**
 * Lookup helper, which allows to get a context variable.
 *
 * It was introduced with dynamic partials:
 *
 * 
 * {{> (lookup '.' 'myVariable') }}
 * 
* * @author edgar * @since 2.2.0 */ public class LookupHelper implements Helper { /** * A singleton instance of this helper. */ public static final Helper INSTANCE = new LookupHelper(); /** * The helper's name. */ public static final String NAME = "lookup"; @Override public CharSequence apply(final Object context, final Options options) throws IOException { if (context == null) { return null; } if (options.params.length <= 0) { return context.toString(); } Context ctx = Context.newBuilder(options.context, context).build(); Object lookup = ctx.get(options.param(0).toString()); if (lookup == null) { return null; } return lookup.toString(); } }