/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISupports.idl"

#include "mozIStorageValueArray.idl"

interface mozIStorageConnection;
interface nsIArray;
interface nsIVariant;

/**
 * mozIStorageFunction is to be implemented by storage consumers that
 * wish to receive callbacks during the request execution.
 *
 * SQL can apply functions to values from tables. Examples of
 * such functions are MIN(a1,a2) or SQRT(num). Many functions are
 * implemented in SQL engine.
 *
 * This interface allows consumers to implement their own,
 * problem-specific functions.
 * These functions can be called from triggers, too.
 *
 */
[scriptable, function, uuid(9ff02465-21cb-49f3-b975-7d5b38ceec73)]
interface mozIStorageFunction : nsISupports {
  /**
   * onFunctionCall is called when execution of a custom
   * function should occur.
   *
   * @param aNumArguments         The number of arguments
   * @param aFunctionArguments    The arguments passed in to the function
   *
   * @returns any value as Variant type.
   */

  nsIVariant onFunctionCall(in mozIStorageValueArray aFunctionArguments);
};