-- Created on: 1997-11-17
-- Created by: Jean-Louis Frenkel
-- Copyright (c) 1997-1999 Matra Datavision
-- Copyright (c) 1999-2014 OPEN CASCADE SAS
--
-- This file is part of Open CASCADE Technology software library.
--
-- This library is free software; you can redistribute it and/or modify it under
-- the terms of the GNU Lesser General Public License version 2.1 as published
-- by the Free Software Foundation, with special exception defined in the file
-- OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
-- distribution for complete text of the license and disclaimer of any warranty.
--
-- Alternatively, this file may be used under the terms of Open CASCADE
-- commercial license or contractual agreement.

deferred class MetaDataDriver from CDF inherits Transient from Standard
    ---Purpose: this class list the method that must be available for
    --          a specific DBMS

uses
    Document from CDM, MetaData from CDM,
    ExtendedString from TCollection,
    ReferenceIterator from PCDM
    
raises 
    NotImplemented from Standard
is

    Initialize;

    ---Category: virtual methods

    HasVersionCapability(me: mutable)
    ---Purpose: returns true if the MetaDataDriver can manage different
    --          versions of a Data.
    --          By default, returns Standard_False.
    returns Boolean from Standard
    is virtual;

    CreateDependsOn(me: mutable; aFirstData: MetaData from CDM;
                                aSecondData: MetaData from CDM)
    ---Purpose: Creates a "Depends On"  relation between two Datas.
    --          By default does nothing
    is virtual;
    
    CreateReference(me: mutable; aFrom, aTo: MetaData from CDM; aReferenceIdentifier: Integer from Standard; aToDocumentVersion: Integer from Standard)
    is virtual;
    
    HasVersion(me: mutable; aFolder, aName: ExtendedString from TCollection)
    returns Boolean from Standard
    ---Purpose: by default return Standard_True.
    is virtual;
    
    BuildFileName(me: mutable; aDocument: Document from CDM)
    returns ExtendedString from TCollection
    is deferred;

    SetName(me: mutable; aDocument: Document from CDM; aName: ExtendedString from TCollection)
    returns ExtendedString from TCollection
    is virtual;
    ---Purpose: this methods  is usefull if the name  of an  object --
    --           depends on  the metadatadriver. For  example a Driver
    --           -- based  on the operating  system can choose to  add
    --           the extension of file to create to the object.
    
---Category: Deferred methods

    ---Overview: inquiring can be made either using a folder, a name and eventually
    --           a version 
    --           or a path which is the concatenation of a folder, a name  and eventually
    --           a version.
    Find(me: mutable; aFolder, aName, aVersion: ExtendedString from TCollection)
    returns Boolean from Standard
    ---Purpose: should indicate whether meta-data exist in the DBMS corresponding 
    --          to the Data.
    --          aVersion may be NULL;
    is deferred;
    
    HasReadPermission(me: mutable; aFolder, aName, aVersion: ExtendedString from TCollection)
    returns Boolean from Standard
    is deferred;
    
    MetaData(me: mutable; aFolder, aName, aVersion: ExtendedString from TCollection)
    returns MetaData from CDM
    ---Purpose: should return the MetaData stored in the DBMS with the meta-data
    --          corresponding to the Data. If the MetaDataDriver has version management capabilities
    --          the version has to be set in the returned MetaData.
    --          aVersion may be NULL
    --          MetaData is called by GetMetaData
    --          If the version is  set to NULL, MetaData should return
    --          the last version of the metadata 
    is deferred;
    
    LastVersion(me: mutable; aMetaData: MetaData from CDM)
    returns MetaData from CDM
    is virtual;
    ---Purpose: by default returns aMetaDATA
	    
--    MetaData(me: mutable; aPath: ExtendedString from TCollection)
--    returns MetaData from CDM
    ---Purpose: should return the MetaData stored in the DBMS with the meta-data
    --          corresponding to the path. If the MetaDataDriver has version management capabilities
    --          the version has to be set in the returned MetaData.
    --          MetaData is called by GetMetaData
    --          If the version is not included in the path , MetaData should return
    --          the last version of the metadata 
--    is deferred;
    


    
    CreateMetaData(me: mutable; aDocument: Document from CDM;
    	         aFileName: ExtendedString from TCollection)
    ---Purpose:  should create meta-data corresponding to aData and maintaining a meta-link
    --           between these meta-data and aFileName
    --           CreateMetaData is called by CreateData
    returns  MetaData from CDM
    ---Purpose: If the metadata-driver 
    --          has version capabilities, version must be set in the returned Data.
    is deferred;
    
    FindFolder(me: mutable; aFolder: ExtendedString from TCollection)
    returns Boolean from Standard
    is deferred;

   DefaultFolder(me: mutable) returns ExtendedString from TCollection
   is deferred;
   
   
---Category:  methods about references.

    ReferenceIterator(me: mutable)
    returns ReferenceIterator from PCDM
    is virtual;
    

    Find(me: mutable; aFolder, aName: ExtendedString from TCollection)
    returns Boolean from Standard;
    ---Purpose: calls Find with an empty version

    MetaData(me: mutable; aFolder, aName: ExtendedString from TCollection)
    returns MetaData from CDM;
    ---Purpose: calls MetaData with an empty version
    

end MetaDataDriver from CDF;