openvidu/openvidu-browser/src/OpenViduInternal/KurentoUtils/kurento-jsonrpc/packers/JsonRPC.js

/**
 * JsonRPC 2.0 packer
 */

/**
 * Pack a JsonRPC 2.0 message
 *
 * @param {Object} message - object to be packaged. It requires to have all the
 *   fields needed by the JsonRPC 2.0 message that it's going to be generated
 *
 * @return {String} - the stringified JsonRPC 2.0 message
 */
function pack(message, id) {
  var result = {
    jsonrpc: "2.0"
  };

  // Request
  if (message.method) {
    result.method = message.method;

    if (message.params)
      result.params = message.params;

    // Request is a notification
    if (id != undefined)
      result.id = id;
  }

  // Response
  else if (id != undefined) {
    if (message.error) {
      if (message.result !== undefined)
        throw new TypeError("Both result and error are defined");

      result.error = message.error;
    } else if (message.result !== undefined)
      result.result = message.result;
    else
      throw new TypeError("No result or error is defined");

    result.id = id;
  };

  return JSON.stringify(result);
};

/**
 * Unpack a JsonRPC 2.0 message
 *
 * @param {String} message - string with the content of the JsonRPC 2.0 message
 *
 * @throws {TypeError} - Invalid JsonRPC version
 *
 * @return {Object} - object filled with the JsonRPC 2.0 message content
 */
function unpack(message) {
  var result = message;

  if (typeof message === 'string' || message instanceof String) {
    result = JSON.parse(message);
  }

  // Check if it's a valid message

  var version = result.jsonrpc;
  if (version !== '2.0')
    throw new TypeError("Invalid JsonRPC version '" + version + "': " + message);

  // Response
  if (result.method == undefined) {
    if (result.id == undefined)
      throw new TypeError("Invalid message: " + message);

    var result_defined = result.result !== undefined;
    var error_defined = result.error !== undefined;

    // Check only result or error is defined, not both or none
    if (result_defined && error_defined)
      throw new TypeError("Both result and error are defined: " + message);

    if (!result_defined && !error_defined)
      throw new TypeError("No result or error is defined: " + message);

    result.ack = result.id;
    delete result.id;
  }

  // Return unpacked message
  return result;
};


exports.pack = pack;
exports.unpack = unpack;