io.knotx.knot.templating.impl.HandlebarsFragment.java Source code

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Here is the source code for io.knotx.knot.templating.impl.HandlebarsFragment.java

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/*
 * Copyright (C) 2016 Cognifide Limited
 *
 * 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 io.knotx.knot.templating.impl;

import com.github.jknack.handlebars.Context;
import com.github.jknack.handlebars.Handlebars;
import com.github.jknack.handlebars.Template;
import io.knotx.dataobjects.Fragment;
import io.knotx.fragments.FragmentContentExtractor;
import io.knotx.knot.templating.handlebars.JsonObjectValueResolver;
import io.vertx.core.logging.Logger;
import io.vertx.core.logging.LoggerFactory;
import java.io.IOException;
import org.apache.commons.lang3.StringUtils;

class HandlebarsFragment {

    private static final Logger LOGGER = LoggerFactory.getLogger(HandlebarsFragment.class);

    private static final int MAX_FRAGMENT_CONTENT_LOG_LENGTH = 256;

    private final Fragment fragment;

    private final String unwrappedContent;

    HandlebarsFragment(Fragment fragment) {
        this.fragment = fragment;
        this.unwrappedContent = FragmentContentExtractor.unwrapContent(fragment);
    }

    String compileWith(Handlebars handlebars) {
        try {
            Template compiledFragment = handlebars.compileInline(unwrappedContent);
            LOGGER.trace("Applying context [{}] to fragment [{}]", fragment.context(), StringUtils
                    .abbreviate(fragment.content().replaceAll("[\n\r\t]", ""), MAX_FRAGMENT_CONTENT_LOG_LENGTH));
            return compiledFragment
                    .apply(Context.newBuilder(fragment.context()).push(JsonObjectValueResolver.INSTANCE).build());
        } catch (IOException e) {
            LOGGER.error("Could not process fragment [{}]", fragment.content(), e);
            throw new IllegalStateException("Handlebars fragment can not be evaluated correctly.");
        }
    }

}