package org.json.simple.parser;

import java.io.IOException;

/**
 * A simplified and stoppable SAX-like content handler for stream processing of
 * JSON text.
 * 
 * @see org.xml.sax.ContentHandler
 * @see org.json.simple.parser.JSONParser#parse(java.io.Reader, ContentHandler,
 *      boolean)
 * 
 * @author FangYidong<fangyidong@yahoo.com.cn>
 */
public interface ContentHandler
{
  /**
   * Receive notification of the beginning of JSON processing. The parser will
   * invoke this method only once.
   * 
   * @throws ParseException
   *           - JSONParser will stop and throw the same exception to the caller
   *           when receiving this exception.
   */
  void startJSON() throws ParseException, IOException;

  /**
   * Receive notification of the end of JSON processing.
   * 
   * @throws ParseException
   */
  void endJSON() throws ParseException, IOException;

  /**
   * Receive notification of the beginning of a JSON object.
   * 
   * @return false if the handler wants to stop parsing after return.
   * @throws ParseException
   *           - JSONParser will stop and throw the same exception to the caller
   *           when receiving this exception.
   * @see #endJSON
   */
  boolean startObject() throws ParseException, IOException;

  /**
   * Receive notification of the end of a JSON object.
   * 
   * @return false if the handler wants to stop parsing after return.
   * @throws ParseException
   * 
   * @see #startObject
   */
  boolean endObject() throws ParseException, IOException;

  /**
   * Receive notification of the beginning of a JSON object entry.
   * 
   * @param key
   *          - Key of a JSON object entry.
   * 
   * @return false if the handler wants to stop parsing after return.
   * @throws ParseException
   * 
   * @see #endObjectEntry
   */
  boolean startObjectEntry(String key) throws ParseException, IOException;

  /**
   * Receive notification of the end of the value of previous object entry.
   * 
   * @return false if the handler wants to stop parsing after return.
   * @throws ParseException
   * 
   * @see #startObjectEntry
   */
  boolean endObjectEntry() throws ParseException, IOException;

  /**
   * Receive notification of the beginning of a JSON array.
   * 
   * @return false if the handler wants to stop parsing after return.
   * @throws ParseException
   * 
   * @see #endArray
   */
  boolean startArray() throws ParseException, IOException;

  /**
   * Receive notification of the end of a JSON array.
   * 
   * @return false if the handler wants to stop parsing after return.
   * @throws ParseException
   * 
   * @see #startArray
   */
  boolean endArray() throws ParseException, IOException;

  /**
   * Receive notification of the JSON primitive values: java.lang.String,
   * java.lang.Number, java.lang.Boolean null
   * 
   * @param value
   *          - Instance of the following: java.lang.String, java.lang.Number,
   *          java.lang.Boolean null
   * 
   * @return false if the handler wants to stop parsing after return.
   * @throws ParseException
   */
  boolean primitive(Object value) throws ParseException, IOException;

}