-- File:	CDF_Session.cdl
-- Created:	Thu Aug  7 17:28:05 1997
-- Author:	Jean-Louis Frenkel
--		<rmi@frilox.paris1.matra-dtv.fr>
---Copyright:	 Matra Datavision 1997

class Session from CDF inherits Transient from Standard


uses
    Directory from CDF,
    ExtendedString from TCollection,
    Application from CDF, 
    MetaDataDriver from CDF, 
    Writer from PCDM
raises

    NoSuchObject from Standard,MultiplyDefined from Standard

is
    Create  returns mutable Session from CDF
    raises MultiplyDefined from Standard;

    Exists(myclass)
--- Purpose: returns true if a session has been created.
    returns Boolean from Standard;
    
    CurrentSession(myclass) returns mutable Session from CDF;
    ---Purpose: returns the only one instance of Session 
    --          that has been created.

    
    Directory(me) returns mutable Directory from CDF;
    ---Purpose: returns the directory of the session;
    ---Level: Public 

    
---Category: current application management
    HasCurrentApplication(me) returns Boolean from Standard;
    
    CurrentApplication(me) returns mutable Application from CDF
    raises NoSuchObject from Standard;
    
    SetCurrentApplication(me: mutable; anApplication: Application from CDF);
    
    UnsetCurrentApplication(me: mutable);


---Category: database related methods

    MetaDataDriver(me) returns MetaDataDriver from CDF
    raises NoSuchObject from Standard;
    
    
    LoadDriver(me: mutable);

fields

    myDirectory            : Directory from CDF;
    myCurrentApplication   : Application from CDF;
    myHasCurrentApplication: Boolean from Standard;
    myMetaDataDriver       : MetaDataDriver from CDF;
friends
    class Application from CDF
end Session from CDF;