Exploding AEC objects after setting implied selection is behaving inconsistently

[nshupeFMPE3]

I was trying to add exploding AEC objects as a step in a larger command. 

So in my command class I simply have this

[CommandMethod(nameof(CleanupTest))]
public void CleanupTest()
{
    Cleanup.CleanupTool.Cleanup();
}

Then in the Cleanup method 

public static class CleanupTool
{
    private static Database _db = null;
    private static Editor _ed = null;
    private static List<ObjectId> _allEntities = new List<ObjectId>();

    public static void Cleanup()
    {
        Document doc = Application.DocumentManager.MdiActiveDocument;
        _db = doc.Database;
        _ed = doc.Editor;
        _allEntities.Clear();

        _db.UnlockTurnOnThawAllLayers();
        
        GetAllEntities(_ed);
        if (!_allEntities.Any()) return;

        ExplodeAEC();

        

        bool moreBlocks = true;

        while (moreBlocks)
        {
            moreBlocks = ExplodeBlocks();
        }
      ///the rest of my code

   }
}

I get a selection so I know what entities the user wants to operate with, and then I try to explode the AEC objects which requires sending the EXPLODE command instead of exploding using the API

private static void GetAllEntities(Editor ed)
{
    var totalSelection = ed.GetSelection(new PromptSelectionOptions
    {
        MessageForAdding = $"\nSelect the FLOOR plan to clean:"
    });
    if (totalSelection.Status != PromptStatus.OK) return;

    _allEntities = totalSelection.Value.GetObjectIds().ToList();
}

private static void ExplodeAEC()
{
    var aec = _allEntities
        .Where(id => id.ObjectClass.DxfName.Contains("AEC"))
        .ToList();

    if (!aec.Any()) return;

    _ed.SetImpliedSelection(aec.ToArray());

    //_ed.Document.SendStringToExecute("._EXPLODE", true, false, false);
    _ed.Command("._EXPLODE", "P");
}

Neither using Editor.Command() or Document.SendStringToExecute() work in this context. The terminal says this

Select the FLOOR plan to clean:
._EXPLODE
Select object: P
*Invalid selection*
Expects a point or Last/ALL/Group

But If I instead extract the AEC portion into its own command then it works

[CommandMethod(nameof(CleanAEC))]
public void CleanAEC()
{
    var _ed = Active.Editor;

    var selection = _ed.GetSelection();

    if (selection.Status != PromptStatus.OK) return;

    var aec = selection.Value.GetObjectIds()
        .Where(id => id.ObjectClass.DxfName.Contains("AEC"))
        .ToList();

    if (!aec.Any()) return;

    _ed.SetImpliedSelection(aec.ToArray());

    _ed.Document.SendStringToExecute("._EXPLODE P", true, false, false);
}

I have tried commenting out the rest of the Cleanup method code to see if something that happens after ExploeAEC is causing the problem. Unfortunately it did not seem to help.

[ActivistInvestor · Accepted solution]

Try it like this:

private static void ExplodeAEC()
{
   var aec = _allEntities
         .Where(id => id.ObjectClass.DxfName.Contains("AEC"))
         .ToArray();

   if(!aec.Any()) return;

   var ss = SelectionSet.FromObjectIds(aec);
   ed.InitCommandVersion(2);
   ed.Command("._EXPLODE", ss, "");
}

[nshupeFMPE3]

Of course that worked. As always thank you very much. Is there any documentation regarding Editor.InitCommandVersion()? I like to learn more about these obscure "tools" so I might be ready next time.

[ActivistInvestor · Accepted solution]

InitCommandVersion() tells the next command to be issued to use the same prompting sequence in scripted commands that it uses when the command is used interactively by the user.

A command will always use the legacy prompting sequence (if there is one) when it is being scripted, to avoid breaking script compatibility. InitCommandVersion() allows you to override that, to have a command use the same prompting sequence in scripted input that's used when the command is used interactively.

The EXPLODE command originally accepted only a single entity. At some point, it was changed to allow multiple objects to be selected, which involves a different prompting sequence. So in this case, InitCommandVersion() is telling EXPLODE to allow multiple objects to be supplied when it is being scripted, which it would otherwise not do.