-- File:	IFSelect_SessionDumper.cdl
-- Created:	Thu Nov  4 10:47:11 1993
-- Author:	Christian CAILLET
--		<cky@sdsun2>
---Copyright:	 Matra Datavision 1993


deferred class SessionDumper  from IFSelect  inherits TShared

    ---Purpose : A SessionDumper is called by SessionFile. It takes into
    --           account a set of classes (such as Selections, Dispatches ...).
    --           SessionFile writes the Type (as defined by cdl) of each Item
    --           and its general Parameters. It manages the names of the Items.
    --           
    --           A SessionDumper must be able to Write the Parameters which are
    --           own of each Item it takes into account, given its Class, then
    --           to Recognize the Type and Read its Own Parameters to create
    --           an Item of this Type with these own Parameters.
    --           
    --           Then, there must be defined one sub-type of SessionDumper per
    --           consistent set of classes (e.g. a package).
    --           
    --           By Own Parameters, understand Parameters given at Creation Time
    --           if there are, or specific of a given class, apart from those
    --           defined at superclass levels (e.g. Final Selection for a
    --           Dispatch, Input Selection for a SelectExtract or SelectDeduct,
    --           Direct Status for a SelectExtract, etc...).
    --           
    --           The Parameters are those stored in a WorkSession, they can be
    --           of Types : IntParam, HAsciiString (for TextParam), Selection,
    --           Dispatch.
    --           
    --           SessionDumpers are organized in a Library which is used by
    --           SessionFile. They are put at Creation Time in this Library.

uses Transient, AsciiString from TCollection, SessionFile

is

    Initialize;
    ---Purpose : The Initialization puts a just created SessionDumper in the
    --           Library of SessionDumper. Then, it suffices to create once
    --           a SessionDumper to fill the Library with it

    First (myclass) returns SessionDumper;
    ---Purpose : Returns the First item of the Library of Dumper. The Next ones
    --           are then obtained by Next on the returned items

    Next (me) returns SessionDumper;
    ---Purpose : Returns the Next SesionDumper in the Library. Returns a Null
    --           Handle at the End.

    WriteOwn (me; file : in out SessionFile; item : Transient)
    	returns Boolean  is deferred;
    ---Purpose : Writes the Own Parameters of a given Item, if it forecast to
    --           manage its Type.
    --           Returns True if it has recognized the Type of the Item (in
    --           this case, it is assumed to have written the Own Parameters if
    --           there are some), False else : in that case, SessionFile will
    --           try another SessionDumper in the Library.
    --           WriteOwn can use these methods from SessionFile : SendVoid,
    --           SendItem, SendText, and if necessary, WorkSession.

    ReadOwn  (me; file : in out SessionFile;
    	    type : AsciiString from TCollection; item : out mutable Transient)
    	returns Boolean  is deferred;
    ---Purpose : Recognizes a Type (given as <type>) then Creates an Item of
    --           this Type with the Own Parameter, as required.
    --           Returns True if it has recognized the Type (in this case, it
    --           is assumed to have created the Item, returned as <item>),
    --           False else : in that case, SessionFile will try another
    --           SessionDumper in the Library.
    --           ReadOwn can use these methods from SessionFile to access Own
    --           Parameters : NbOwnParams, IsVoid, IsText, TextValue, ItemValue

fields

    thenext : SessionDumper;

end SessionDumper;