Read STEP Instance ID's from Shapes

[flolu]

I'm using the following code to read a STEP file:

oc.FS.createDataFile('/', fileName, fileText, true, true, true)

const reader = new oc.STEPControl_Reader_1()
const readSuccess = reader.ReadFile(fileName) === oc.IFSelect_ReturnStatus.IFSelect_RetDone

if (!readSuccess) {
  throw 'Failed to convert STEP file to OCCT shape'
}

reader.TransferRoots(new oc.Message_ProgressRange_1())
const shape = reader.OneShape()
oc.FS.unlink(fileName)

const faceExplorer = new oc.TopExp_Explorer_1()

for (
  // @ts-ignore
  faceExplorer.Init(shape, oc.TopAbs_ShapeEnum.TopAbs_FACE, oc.TopAbs_ShapeEnum.TopAbs_SHAPE);
  faceExplorer.More();
  faceExplorer.Next()
) {
  const currentShape = faceExplorer.Current()
  const face = oc.TopoDS.Face_1(currentShape)
  // How to get the STEP instance ID of `face`?
}

And let's suppose this data is inside my STEP file:

#417=ADVANCED_FACE('face_1',(#112),#405,.F.);
#418=ADVANCED_FACE('face_2',(#113),#406,.F.);
#419=ADVANCED_FACE('face_3',(#114),#407,.F.);

How can I read the ID's of the ADVANCED_FACE instances? (#417, #418 and #419)

---

Maybe it is possible with a XSControl_TransferReader (reader.WS().get().TransferReader().get()), but I couldn't make it work.

[flolu]

Solution: https://github.com/tpaviot/pythonocc-core/issues/1119#issuecomment-1231562360

[gabrielgriesser]

Hello, how did you do ?

I can't find an Opencascade.js code working for this one :(, only pythonocc-core

[flolu]

Hey @gabrielgriesser. I'm sorry. I only used this with pythonocc-core and I have never checked if it is also available in Opencascade.js. I recommend you to create a new issue in this repository. Maybe someone from the creators know how to access the IdentLabel

[gabrielgriesser]

Thank you for your answer @flolu

I used your code with the opencascade.js library, but the function DownCast in line item = StepRepr_RepresentationItem.DownCast(item) cannot be found in this library.

I presume that this function has not been imported yet.

Here is my code

let anExplorer = new oc.TopExp_Explorer_2(shape, oc.TopAbs_ShapeEnum.TopAbs_FACE, oc.TopAbs_ShapeEnum.TopAbs_SHAPE);

  for (anExplorer.Init(shape, oc.TopAbs_ShapeEnum.TopAbs_FACE, oc.TopAbs_ShapeEnum.TopAbs_FACE); anExplorer.More(); anExplorer.Next()) {
    let item = transferReader.EntityFromShapeResult(anExplorer.Current(), 4);
    console.log("ITEM : " + model.get().IdentLabel(item));
    // print only 0
  }

@donalffons have you some tips on it ?