YamlConstructor.java

/*
 * This file is part of Foxbot.
 *
 *     Foxbot is free software: you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 *
 *     Foxbot is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public License
 *     along with Foxbot. If not, see <http://www.gnu.org/licenses/>.
 */

package co.foxdev.foxbot.config.yamlconfig.file;

import co.foxdev.foxbot.config.yamlconfig.serialization.ConfigurationSerialization;
import org.yaml.snakeyaml.constructor.SafeConstructor;
import org.yaml.snakeyaml.error.YAMLException;
import org.yaml.snakeyaml.nodes.Node;
import org.yaml.snakeyaml.nodes.Tag;

import java.util.LinkedHashMap;
import java.util.Map;

public class YamlConstructor extends SafeConstructor
{

    public YamlConstructor()
    {
        this.yamlConstructors.put(Tag.MAP, new ConstructCustomObject());
    }

    private class ConstructCustomObject extends ConstructYamlMap
    {

        @Override
        public Object construct(Node node)
        {
            if (node.isTwoStepsConstruction())
            {
                throw new YAMLException("Unexpected referential mapping structure. Node: " + node);
            }

            Map<?, ?> raw = (Map<?, ?>) super.construct(node);

            if (raw.containsKey(ConfigurationSerialization.SERIALIZED_TYPE_KEY))
            {
                Map<String, Object> typed = new LinkedHashMap<String, Object>(raw.size());

                for (Map.Entry<?, ?> entry : raw.entrySet())
                {
                    typed.put(entry.getKey().toString(), entry.getValue());
                }

                try
                {
                    return ConfigurationSerialization.deserializeObject(typed);
                }
                catch (IllegalArgumentException ex)
                {
                    throw new YAMLException("Could not deserialize object", ex);
                }
            }

            return raw;
        }

        @Override
        public void construct2ndStep(Node node, Object object)
        {
            throw new YAMLException("Unexpected referential mapping structure. Node: " + node);
        }
    }
}