com.synflow.cx.internal.instantiation.properties.JsonMaker.java Source code

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Here is the source code for com.synflow.cx.internal.instantiation.properties.JsonMaker.java

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/*******************************************************************************
 * Copyright (c) 2014-2015 Synflow SAS.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Matthieu Wipliez - initial API and implementation and/or initial documentation
 *******************************************************************************/
package com.synflow.cx.internal.instantiation.properties;

import java.util.IdentityHashMap;
import java.util.Map;

import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonNull;
import com.google.gson.JsonObject;
import com.google.gson.JsonPrimitive;
import com.synflow.cx.cx.Array;
import com.synflow.cx.cx.CxExpression;
import com.synflow.cx.cx.Element;
import com.synflow.cx.cx.Null;
import com.synflow.cx.cx.Obj;
import com.synflow.cx.cx.Pair;
import com.synflow.cx.cx.Primitive;
import com.synflow.cx.cx.util.CxSwitch;
import com.synflow.cx.instantiation.IInstantiator;
import com.synflow.cx.internal.ErrorMarker;
import com.synflow.models.dpn.Entity;
import com.synflow.models.ir.util.ValueUtil;

/**
 * This class transforms our Javascript-like syntax to pure JSON.
 * 
 * @author Matthieu Wipliez
 * 
 */
public class JsonMaker extends CxSwitch<JsonElement> {

    private Entity entity;

    private IInstantiator instantiator;

    private Map<JsonElement, ErrorMarker> mapping;

    public JsonMaker(IInstantiator instantiator, Entity entity) {
        mapping = new IdentityHashMap<>();
        this.instantiator = instantiator;
        this.entity = entity;
    }

    @Override
    public JsonArray caseArray(Array array) {
        JsonArray jsonArray = new JsonArray();
        mapping.put(jsonArray, new ErrorMarker(array));
        for (Element element : array.getElements()) {
            jsonArray.add(doSwitch(element));
        }
        return jsonArray;
    }

    @Override
    public JsonPrimitive caseCxExpression(CxExpression expression) {
        Object value = instantiator.evaluate(entity, expression);
        JsonPrimitive primitive;
        if (ValueUtil.isBool(value)) {
            primitive = new JsonPrimitive((Boolean) value);
        } else if (ValueUtil.isFloat(value) || ValueUtil.isInt(value)) {
            primitive = new JsonPrimitive((Number) value);
        } else if (ValueUtil.isString(value)) {
            primitive = new JsonPrimitive((String) value);
        } else {
            return null;
        }

        mapping.put(primitive, new ErrorMarker(expression));
        return primitive;
    }

    @Override
    public JsonNull caseNull(Null null_) {
        return JsonNull.INSTANCE;
    }

    @Override
    public JsonObject caseObj(Obj obj) {
        JsonObject jsonObj = new JsonObject();
        mapping.put(jsonObj, new ErrorMarker(obj));
        for (Pair pair : obj.getMembers()) {
            Element value = pair.getValue();
            if (value != null) {
                String key = pair.getKey();
                jsonObj.add(key, doSwitch(value));
            }
        }
        return jsonObj;
    }

    @Override
    public JsonElement casePrimitive(Primitive primitive) {
        return doSwitch(primitive.getValue());
    }

    /**
     * Returns the error marker that corresponds to the given JSON element.
     * 
     * @param element
     *            a JSON element
     * @return an error marker
     */
    public ErrorMarker getMapping(JsonElement element) {
        return mapping.get(element);
    }

    /**
     * Transforms the given object to JSON.
     * 
     * @param obj
     *            an object
     * @return a JSON object
     */
    public JsonObject toJson(Obj obj) {
        return (JsonObject) doSwitch(obj);
    }

}