{
* 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/
*
* Copyright (C) 2008-2013, Peter Johnson (www.delphidabbler.com).
*
* $Rev$
* $Date$
*
* Implements objects that can create suitable objects that can be used to load
* and save the snippets database.
}
unit CS.Database.IO.Factory;
interface
uses
// Project
CS.Database.IO.Types,
UBaseObjects;
type
/// <summary>Factory class used to create database loader and writer objects
/// for use in loading and saving the snippets database.</summary>
TDatabaseIOFactory = class(TNoConstructObject)
public
/// <summary>Creates and returns an instance of a database loader object
/// that can be used to load the database.</summary>
/// <remarks>If a database in native format is present a loader for that
/// database is returned. If there is no native database then any legacy
/// XML format database is looked for and a loader for that is returned if
/// found. If there is no database present at all then a special "empty
/// database" loader is returned.</remarks>
class function CreateLoader: IDatabaseLoader;
/// <summary>Creates and returns an instance of a an object that can be
/// used to save the database.</summary>
/// <remarks>This method always returns an writer object that saves in
/// native format. No other output formats are supported.</remarks>
class function CreateWriter: IDatabaseWriter;
end;
implementation
uses
// Project
CS.Database.IO.Empty,
CS.Database.IO.Legacy,
CS.Database.IO.Native,
UAppInfo;
{ TDatabaseIOFactory }
class function TDatabaseIOFactory.CreateLoader: IDatabaseLoader;
begin
Result := TDBNativeReader.Create(TAppInfo.UserDataDir);
if Result.DatabaseExists then
Exit;
Result := TDBLegacyUserDBReader.Create(TAppInfo.UserDataDir);
if Result.DatabaseExists then
Exit;
Result := TEmptyDBReader.Create;
end;
class function TDatabaseIOFactory.CreateWriter: IDatabaseWriter;
begin
Result := TDBNativeWriter.Create(TAppInfo.UserDataDir);
end;
end.
