Understanding the structure of streams from Revit

Speckle Help Help (Legacy V2)
4

Hi @henkon, just had some fun today hacking a quick Flatten function + some LINQ filtering. I’ve posted the full spiel in our docs right over here (we try to document valid questions and responses!)

Long story short, add this extension method somewhere to your project:

public static class Extensions
{
  // Flattens a base object into all its constituent parts.
  public static IEnumerable<Base> Flatten(this Base obj)
  {
    yield return obj;

    var props = obj.GetDynamicMemberNames();
    foreach (var prop in props)
    {
      var value = obj[prop];
      if (value == null) continue;

      if (value is Base b)
      {
        var nested = b.Flatten();
        foreach (var child in nested) yield return child;
      }

      if (value is IDictionary dict)
      {
        foreach (var dictValue in dict.Values)
        {
          if (dictValue is Base lb)
          {
            foreach (var lbChild in lb.Flatten()) yield return lbChild;
          }
        }
      }

      if (value is IEnumerable enumerable)
      {
        foreach (var listValue in enumerable)
        {
          if (listValue is Base lb)
          {
            foreach (var lbChild in lb.Flatten()) yield return lbChild;
          }
        }
      }
    }
  }
}

Afterwards, you’ll be able to do things such as:

      var data = Helpers.Receive("https://speckle.xyz/streams/0d3cb7cb52/commits/681cdd572c").Result;
      var flatData = data.Flatten().ToList();

      var windows = flatData.FindAll(obj => (string)obj["category"] == "Windows");
      var timberWalls = flatData.FindAll(obj => obj is Objects.BuiltElements.Revit.RevitWall wall && wall.type == "Wall - Timber Clad");
      var rooms = flatData.FindAll(obj => obj is Objects.BuiltElements.Room);
      var levels = flatData.FindAll(obj => obj is Objects.BuiltElements.Level).Cast<Objects.BuiltElements.Level>().GroupBy(level => level.name).Select(g => g.First()).ToList();

      Console.WriteLine($"Found {windows.Count} windows.");
      Console.WriteLine($"Found {timberWalls.Count} timber walls.");
      Console.WriteLine($"Found {rooms.Count} rooms.");
      Console.WriteLine($"Found {levels.Count} levels.");
      
      var elementsByLevel = flatData.FindAll(obj => obj["level"] != null).GroupBy(obj => ((Base)obj["level"])["name"]);
      foreach(var grouping in elementsByLevel) {
        Console.WriteLine($"On level {grouping.Key} there are {grouping.Count()} elements.");
      }

Have fun!

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