Create Gable Wall

I discussed creating a wall with a sloped profile using Revit 2009. Now Saikat Bhattacharya created a similar command to answer a similar question in Revit 2012:

Question: Using the Revit user interface, I can create walls that consist of more then four edges, i.e. non-rectangular. Usually they would represent some sort of gable wall in a building. How can I achieve this using the API, please?

Answer: To answer your question, I wrote some quick code which creates a gable wall with seven faces, instead of the usual six faces of a rectangular wall. It creates the following wall:

Jeremy adds: Many thanks to Saikat for setting this up!

I created a new Building Coder sample command CmdCreateGableWall based on Saikat's code. It is similar to the existing external command CmdSlopedWall, updated to use new Revit API functionality to use manual transaction mode and filtered element collectors and LINQ to determine a suitable wall type and level:

[Transaction( TransactionMode.Manual )]
class CmdCreateGableWall : IExternalCommand
{
  public Result Execute(
    ExternalCommandData commandData,
    ref string message,
    ElementSet elements )
  {
    UIApplication uiapp = commandData.Application;
    UIDocument uidoc = uiapp.ActiveUIDocument;
    Application app = uiapp.Application;
    Document doc = uidoc.Document;
 
    // Build a wall profile for the wall creation 
 
    XYZ [] pts = new XYZ[] {
      XYZ.Zero,
      new XYZ( 20, 0, 0 ),
      new XYZ( 20, 0, 15 ),
      new XYZ( 10, 0, 30 ),
      new XYZ( 0, 0, 15 )
    };
 
    // Get application creation object 
 
    Autodesk.Revit.Creation.Application appCreation 
      = app.Create;
 
    // Create wall profile
 
    CurveArray profile = new CurveArray();
 
    XYZ q = pts[ pts.Length - 1 ];
 
    foreach( XYZ p in pts )
    {
      profile.Append( appCreation.NewLineBound( 
        q, p ) );
 
      q = p;
    }
 
    XYZ normal = XYZ.BasisY;
 
    //WallType wallType 
    //  = new FilteredElementCollector( doc )
    //    .OfClass( typeof( WallType ) )
    //    .First<Element>( e 
    //      => e.Name.Contains( "Generic" ) ) 
    //    as WallType;
 
    WallType wallType
      = new FilteredElementCollector( doc )
        .OfClass( typeof( WallType ) )
        .First<Element>()
          as WallType;
 
    Level level 
      = new FilteredElementCollector( doc )
        .OfClass( typeof( Level ) )
        .First<Element>( e 
          => e.Name.Equals( "Level 1" ) ) 
        as Level;
 
    Transaction trans = new Transaction( doc );
 
    trans.Start( "Create Gable Wall" );
 
    Wall wall = doc.Create.NewWall( 
      profile, wallType, level, true, normal );
 
    trans.Commit();
 
    return Result.Succeeded;
  }
}

Here is version 2012.0.88.0 of The Building Coder samples including the new command CmdCreateGableWall as well as the existing simpler CmdSlopedWall one.