/**

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

 *

 * Copyright 2013-2014 Oracle and/or its affiliates. All rights reserved.

 *

 * Oracle and Java are registered trademarks of Oracle and/or its affiliates.

 * Other names may be trademarks of their respective owners.

 *

 * The contents of this file are subject to the terms of either the GNU

 * General Public License Version 2 only ("GPL") or the Common

 * Development and Distribution License("CDDL") (collectively, the

 * "License"). You may not use this file except in compliance with the

 * License. You can obtain a copy of the License at

 * http://www.netbeans.org/cddl-gplv2.html

 * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the

 * specific language governing permissions and limitations under the

 * License.  When distributing the software, include this License Header

 * Notice in each file and include the License file at

 * nbbuild/licenses/CDDL-GPL-2-CP.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the GPL Version 2 section of the License file that

 * accompanied this code. If applicable, add the following below the

 * License Header, with the fields enclosed by brackets [] replaced by

 * your own identifying information:

 * "Portions Copyrighted [year] [name of copyright owner]"

 *

 * Contributor(s):

 *

 * The Original Software is NetBeans. The Initial Developer of the Original

 * Software is Oracle. Portions Copyright 2013-2014 Oracle. All Rights Reserved.

 *

 * If you wish your version of this file to be governed by only the CDDL

 * or only the GPL Version 2, indicate your decision by adding

 * "[Contributor] elects to include this software in this distribution

 * under the [CDDL or GPL Version 2] license." If you do not indicate a

 * single choice of license, a recipient has the option to distribute

 * your version of this file under either the CDDL, the GPL Version 2 or

 * to extend the choice of license to its licensees as provided above.

 * However, if you add GPL Version 2 code and therefore, elected the GPL

 * Version 2 license, then the option applies only if the new code is

 * made subject to such option by the copyright holder.

 */

package org.apidesign.html.json.spi;

import java.io.IOException;

import java.io.InputStream;

import org.apidesign.html.context.spi.Contexts.Builder;

/** A {@link Builder service provider interface} responsible for 

 * conversion of JSON objects to Java ones and vice-versa.

 *

 * @author Jaroslav Tulach <jtulach@netbeans.org>

 */

public interface Transfer {

    /**

     * Called to inspect properties of an object (usually a JSON or JavaScript

     * wrapper).

     *

     * @param obj the object to inspect

     * @param props the names of properties to check on the object

     * <code>obj</code>

     * @param values array of the same length as <code>props</code> should be

     * filled by values of properties on the <code>obj</code>. If a property is

     * not defined, a <code>null</code> value should be stored in the array

     */

    public void extract(Object obj, String[] props, Object[] values);

    /** Reads content of a stream and creates its JSON representation.

     * The returned object is implementation dependant. It however needs

     * to be acceptable as first argument of {@link #extract(java.lang.Object, java.lang.String[], java.lang.Object[]) extract}

     * method.

     * 

     * @param is input stream to read data from

     * @return an object representing the JSON data

     * @throws IOException if something goes wrong

     */

    public Object toJSON(InputStream is) throws IOException;

    /** Starts the JSON or JSONP query. 

     * 

     * @param call description of the call to make

     */

    public void loadJSON(JSONCall call);

}