-- File:	PCDM_ReadWriter.cdl
-- Created:	Tue Dec  9 08:28:48 1997
-- Author:	Jean-Louis Frenkel
--		<rmi@frilox.paris1.matra-dtv.fr>
---Copyright:	 Matra Datavision 1997

private deferred class ReadWriter from PCDM inherits Transient from Standard

uses
    ExtendedString from TCollection,  
    AsciiString from TCollection, 
    Data from Storage, 
    Document from CDM, 
    MessageDriver from CDM,
    SequenceOfExtendedString from TColStd,  
    BaseDriver from Storage,  
    OpenMode from Storage, 
    SequenceOfReference from PCDM

is

    
    Version(me) returns AsciiString from TCollection
    is deferred;
    ---Purpose: returns PCDM_ReadWriter_1.
    
    WriteReferenceCounter(me; aData: mutable Data from Storage; aDocument: Document from CDM)
    is deferred;
    
    WriteReferences(me; aData: mutable Data from Storage; aDocument: Document from CDM; theReferencerFileName: ExtendedString from TCollection)
    is deferred;

    
    WriteExtensions(me; aData: mutable Data from Storage; aDocument: Document from CDM)
    is deferred;

    
    WriteVersion(me; aData: mutable Data from Storage; aDocument: Document from CDM)
    is deferred;

    
    ReadReferenceCounter(me; theFileName: ExtendedString from TCollection;   
			     theMsgDriver: MessageDriver from CDM)
    returns Integer from Standard
    is deferred;

    ReadReferences(me; aFileName: ExtendedString from TCollection; theReferences: in out  SequenceOfReference from PCDM; theMsgDriver: MessageDriver from CDM)
    is deferred;

    ReadExtensions(me; aFileName: ExtendedString from TCollection; theExtensions: in out  SequenceOfExtendedString from TColStd; theMsgDriver: MessageDriver from CDM)
    is deferred;
    
    ReadDocumentVersion(me; aFileName: ExtendedString from TCollection; theMsgDriver: MessageDriver from CDM)
    returns Integer from Standard
    is deferred;

---Category: commom methods


    Open(myclass; aDriver: in out BaseDriver from Storage; aFileName: ExtendedString from TCollection; anOpenMode: OpenMode from  Storage);
    
    Reader(myclass; aFileName: ExtendedString from TCollection)
    returns ReadWriter from PCDM;
    ---Purpose: returns the convenient Reader for a File.
    --          
    
    Writer(myclass)
    returns ReadWriter from PCDM;
    

    WriteFileFormat(myclass; aData: mutable Data from Storage; aDocument: Document from CDM);
    
    FileFormat(myclass; aFileName: ExtendedString from TCollection)
    returns ExtendedString from TCollection;
    ---Purpose: tries  to get a format  in the  file.  returns an empty
    --          string if the file could not be read or does not have 
    --          a FileFormat information.
end ReadWriter from PCDM;