-- File:	ExternalSources.cdl
-- Created:	Wed Sep 23 11:10:40 1992
-- Author:	Christian CAILLET
--		<cky@phobox>
---Copyright:	 Matra Datavision 1992


class ExternalSources  from IFGraph  inherits GraphContent

    	---Purpose : this class gives entities which are Source of entities of
    	--           a sub-part, but are not contained by this sub-part

uses Transient, EntityIterator, Graph

is

    Create (agraph : Graph) returns ExternalSources;
    ---Purpose : creates empty ExternalSources, ready to work

    GetFromEntity (me : in out; ent : any Transient);
    ---Purpose : adds an entity and its shared ones to the list

    GetFromIter (me : in out; iter : EntityIterator);
    ---Purpose : adds a list of entities (as an iterator) with shared ones

    ResetData (me : in out);
    ---Purpose : Allows to restart on a new data set

    	-- --   Results   -- --
    	--   More-Next-Value give External Source entities

    Evaluate (me : in out) is redefined;
    ---Purpose : Evaluates external sources of a set of entities

    IsEmpty(me : in out) returns Boolean;
    ---Purpose : Returns True if no External Source are found
    --           It means that we have a "root" set
    --           (performs an Evaluation as necessary)

fields

    thegraph : Graph;

end ExternalSources;