private void Stream( ArrayList data, Rebar rebar )
        {
            data.Add( new Snoop.Data.ClassSeparator( typeof( Rebar ) ) );

              data.Add( new Snoop.Data.ElementId( "Bar type", rebar.GetTypeId(), rebar.Document ) );
              data.Add( new Snoop.Data.ElementId( "Rebar shape", rebar.RebarShapeId, rebar.Document ) );
              data.Add( new Snoop.Data.ElementId( "Host", rebar.GetHostId(), rebar.Document ) );
              data.Add( new Snoop.Data.Object( "Distribution path", rebar.GetDistributionPath() ) );
              data.Add( new Snoop.Data.Enumerable( "GetCenterlineCurves(false, false, false)", rebar.GetCenterlineCurves( false, false, false, MultiplanarOption.IncludeOnlyPlanarCurves, 0 ) ) );
              data.Add( new Snoop.Data.String( "LayoutRule", rebar.LayoutRule.ToString() ) );
              if( rebar.LayoutRule != RebarLayoutRule.Single )
              {
            data.Add( new Snoop.Data.Double( "Distribution path length", rebar.ArrayLength ) );
            data.Add( new Snoop.Data.Int( "Quantity", rebar.Quantity ) );
            data.Add( new Snoop.Data.Int( "NumberOfBarPositions", rebar.NumberOfBarPositions ) );
            data.Add( new Snoop.Data.Double( "MaxSpacing", rebar.MaxSpacing ) );
            data.Add( new Snoop.Data.Bool( "BarsOnNormalSide", rebar.BarsOnNormalSide ) );
              }

              data.Add( new Snoop.Data.String( "ScheduleMark", rebar.ScheduleMark ) );
              data.Add( new Snoop.Data.Double( "Volume", rebar.Volume ) );
              data.Add( new Snoop.Data.Double( "TotalLength", rebar.TotalLength ) );
              data.Add( new Snoop.Data.Object( "Normal", rebar.Normal ) );

              //TF
              data.Add( new Snoop.Data.Object( "ConstraintsManager", rebar.GetRebarConstraintsManager() ) );
              //TFEND

              // Bending data
              data.Add( new Snoop.Data.Object( "Bending Data", rebar.GetBendData() ) );

              // Hook information
              addHookInformation2Rebar( data, rebar, 0 );
              addHookInformation2Rebar( data, rebar, 1 );
        }
        private void Stream( ArrayList data, Rebar rebar )
        {
            data.Add( new Snoop.Data.ClassSeparator( typeof( Rebar ) ) );

              data.Add( new Snoop.Data.ElementId( "Bar type", rebar.GetTypeId(), rebar.Document ) );
              data.Add( new Snoop.Data.ElementId( "Rebar shape", rebar.RebarShapeId, rebar.Document ) );
              data.Add( new Snoop.Data.ElementId( "Host", rebar.GetHostId(), rebar.Document ) );
              data.Add( new Snoop.Data.Object( "Distribution path", rebar.GetDistributionPath() ) );
              data.Add( new Snoop.Data.Enumerable( "GetCenterlineCurves(false, false, false)", rebar.GetCenterlineCurves( false, false, false ) ) );
              data.Add( new Snoop.Data.String( "LayoutRule", rebar.LayoutRule.ToString() ) );
              if( rebar.LayoutRule != RebarLayoutRule.Single )
              {
            data.Add( new Snoop.Data.Double( "Distribution path length", rebar.ArrayLength ) );
            data.Add( new Snoop.Data.Int( "Quantity", rebar.Quantity ) );
            data.Add( new Snoop.Data.Int( "NumberOfBarPositions", rebar.NumberOfBarPositions ) );
            data.Add( new Snoop.Data.Double( "MaxSpacing", rebar.MaxSpacing ) );
              }

              //TF
              data.Add( new Snoop.Data.Object( "ConstraintsManager", rebar.GetRebarConstraintsManager() ) );
              //TFEND
        }
        /// <summary>
        /// Implement this method as an external command for Revit.
        /// </summary>
        /// <param name="commandData">An object that is passed to the external application
        /// which contains data related to the command,
        /// such as the application object and active view.</param>
        /// <param name="message">A message that can be set by the external application
        /// which will be displayed if a failure or cancellation is returned by
        /// the external command.</param>
        /// <param name="elements">A set of elements to which the external application
        /// can add elements that are to be highlighted in case of failure or cancellation.</param>
        /// <returns>Return the status of the external command.
        /// A result of Succeeded means that the API external method functioned as expected.
        /// Cancelled can be used to signify that the user cancelled the external operation
        /// at some point. Failure should be returned if the application is unable to proceed with
        /// the operation.</returns>
        public virtual Result Execute(ExternalCommandData commandData
                                      , ref string message, ElementSet elements)
        {
            try
            {
                Document doc = commandData.Application.ActiveUIDocument.Document;
                if (doc == null)
                {
                    return(Result.Failed);
                }

                //Fetch a RebarBarType element to be used in Rebar creation.
                FilteredElementCollector fec = new FilteredElementCollector(doc).OfClass(typeof(RebarBarType));
                if (fec.GetElementCount() <= 0)
                {
                    return(Result.Failed);
                }
                RebarBarType barType   = fec.FirstElement() as RebarBarType;
                Rebar        rebar     = null;
                CurveElement curveElem = null;
                using (Transaction tran = new Transaction(doc, "Create Rebar"))
                {
                    Element   host = null;
                    Selection sel  = commandData.Application.ActiveUIDocument.Selection;
                    try
                    {
                        //Select structural Host.
                        Reference hostRef = sel.PickObject(ObjectType.Element, "Select Host");
                        host = doc.GetElement(hostRef.ElementId);
                        if (host == null)
                        {
                            return(Result.Failed);
                        }
                    }
                    catch (Exception e)
                    {
                        message = e.Message;
                        return(Result.Failed);
                    }

                    try
                    {
                        //Select curve element
                        Reference lineRef = sel.PickObject(ObjectType.Element, "Select Model curve");
                        curveElem = doc.GetElement(lineRef.ElementId) as CurveElement;
                    }
                    catch (Exception)
                    {
                        curveElem = null;
                    }

                    tran.Start();

                    // Create Rebar Free Form by specifying the GUID defining the custom external server.
                    // The Rebar element returned needs to receive constraints, so that regeneration can
                    // call the custom geometry calculations and create the bars
                    rebar = Rebar.CreateFreeForm(doc, RebarUpdateServer.SampleGuid, barType, host);
                    // Get all bar handles to set constraints to them, so that the bar can generate its geometry
                    RebarConstraintsManager        rManager = rebar.GetRebarConstraintsManager();
                    IList <RebarConstrainedHandle> handles  = rManager.GetAllHandles();

                    // if bar has no handles then the server can't generate rebar geometry
                    if (handles.Count <= 0)
                    {
                        tran.RollBack();
                        return(Result.Failed);
                    }

                    // iterate through the rebar handles and prompt for face selection for each of them, to get user input
                    foreach (RebarConstrainedHandle handle in handles)
                    {
                        if (handle.GetHandleType() == RebarHandleType.StartOfBar ||
                            handle.GetHandleType() == RebarHandleType.EndOfBar)
                        {
                            continue;// Start handle and end handle will receive constraints from the custom external server execution
                        }
                        try
                        {
                            Reference reference = sel.PickObject(ObjectType.Face, "Select face for " + handle.GetHandleName());
                            if (reference == null)
                            {
                                continue;
                            }
                            // create constraint using the picked faces and set it to the associated handle
                            List <Reference> refs = new List <Reference>();
                            refs.Add(reference);
                            RebarConstraint constraint = RebarConstraint.Create(handle, refs, true, 0.0);
                            rManager.SetPreferredConstraintForHandle(handle, constraint);
                        }
                        catch (Exception e)
                        {
                            message = e.Message;
                            tran.RollBack();
                            return(Result.Cancelled);
                        }
                    }

                    try
                    {
                        //here we add a value to the shared parameter and add it to the regeneration dependencies
                        Parameter newSharedParam  = rebar.LookupParameter(AddSharedParams.m_paramName);
                        Parameter newSharedParam2 = rebar.LookupParameter(AddSharedParams.m_CurveIdName);
                        if (newSharedParam != null && newSharedParam2 != null)
                        {
                            newSharedParam.Set(0);
                            newSharedParam2.Set(curveElem == null ? -1 : curveElem.Id.IntegerValue);

                            RebarFreeFormAccessor accesRebar = rebar.GetFreeFormAccessor();
                            accesRebar.AddUpdatingSharedParameter(newSharedParam.Id);
                            accesRebar.AddUpdatingSharedParameter(newSharedParam2.Id);
                        }
                        else
                        {
                            // The AddSharedParams command should be executed to create and bind these parameters to rebar.
                        }
                    }
                    catch (Exception ex)
                    {
                        message = ex.Message;
                        tran.RollBack();
                        return(Result.Cancelled);
                    }
                    tran.Commit();
                    return(Result.Succeeded);
                }
            }
            catch (Exception ex)
            {
                message = ex.Message;
                return(Result.Failed);
            }
        }