FormModelSerializer.java

/*
 * Copyright 2016 Red Hat, Inc. and/or its affiliates.
 *
 * 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.kie.workbench.common.forms.serialization.impl;

import java.lang.reflect.Type;

import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParseException;
import com.google.gson.JsonSerializationContext;
import com.google.gson.JsonSerializer;
import org.apache.commons.lang3.StringUtils;
import org.kie.workbench.common.forms.model.FormModel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class FormModelSerializer implements JsonSerializer<FormModel>,
                                            JsonDeserializer<FormModel> {

    private Logger log = LoggerFactory.getLogger(FormModelSerializer.class);

    @Override
    public JsonElement serialize(FormModel formModel,
                                 Type type,
                                 JsonSerializationContext context) {
        JsonElement serializedModel = context.serialize(formModel,
                                                        formModel.getClass());

        serializedModel.getAsJsonObject().addProperty("formModelType",
                                                      formModel.getClass().getName());

        return serializedModel;
    }

    @Override
    public FormModel deserialize(JsonElement json,
                                 Type typeOfT,
                                 JsonDeserializationContext context) throws JsonParseException {

        JsonObject jsonField = json.getAsJsonObject();

        JsonElement jsonClassName = jsonField.get("formModelType");

        if (jsonClassName != null && !StringUtils.isEmpty(jsonClassName.getAsString())) {
            try {
                return context.deserialize(json,
                                           Class.forName(jsonClassName.getAsString()));
            } catch (Exception ex) {
                log.error("Error deserializing formModel",
                          ex);
            }
        }

        return null;
    }
}