EmbedHelper.java

/*
 * Copyright 2014 Minkyu Cho
 *
 * 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 org.trimou.handlebars;

/**
 * Embed the template source.
 *
 * <code>
 * {{embed data.template}}
 * </code>
 *
 * <p>
 * By default, the template source is embedded as a JavaScript snippet.
 * </p>
 *
 * <p>
 * If more than one parameters are specified, the final name to be looked up is
 * made up of concatenated params {@link #toString()} values:
 * </p>
 *
 * <code>
 * {{embed "/base/path" data.template}}
 * </code>
 *
 * @author Minkyu Cho
 * @author Martin Kouba
 */
public class EmbedHelper extends BasicValueHelper {

    private final SourceProcessor processor;

    public EmbedHelper() {
        this((name, source) -> new StringBuilder().append("<script id=\"")
                .append(name.replace("/", "_"))
                .append("\" type=\"text/template\">\n").append(source)
                .append("\n").append("</script>").toString());
    }

    /**
     *
     * @param sourceProcessor
     */
    public EmbedHelper(SourceProcessor sourceProcessor) {
        this.processor = sourceProcessor;
    }

    @Override
    public void execute(Options options) {
        String sourceName;
        if (options.getParameters().size() == 1) {
            sourceName = options.getParameters().get(0).toString();
        } else {
            StringBuilder builder = new StringBuilder();
            for (Object param : options.getParameters()) {
                builder.append(param.toString());
            }
            sourceName = builder.toString();
        }
        options.append(
                processor.process(sourceName, options.source(sourceName)));
    }

    @FunctionalInterface
    public interface SourceProcessor {

        String process(String mustacheName, String mustacheSource);

    }

}