[Bug] Attributes duplicated when a component is created from a body

[JeromeBriot]

Hello,

It seems that attributes are duplicated when a component is created from a body. But the parent reference is lost.

Here is a small code:

import adsk.core, adsk.fusion, adsk.cam, traceback # pylint: disable=import-error

def run(context):
    ui = None
    try:
        app = adsk.core.Application.get()
        ui = app.userInterface

        product = app.activeProduct
        design = adsk.fusion.Design.cast(product)

        rootComp = design.rootComponent
        sketches = rootComp.sketches
        sketch1 = sketches.add(rootComp.yZConstructionPlane)
        sketchLines = sketch1.sketchCurves.sketchLines
        startPoint = adsk.core.Point3D.create(0, 0, 0)
        endPoint = adsk.core.Point3D.create(5.0, 5.0, 0)
        sketchLines.addTwoPointRectangle(startPoint, endPoint)
        prof = sketch1.profiles.item(0)
        extrudes = rootComp.features.extrudeFeatures
        extInput = extrudes.createInput(prof, adsk.fusion.FeatureOperations.NewBodyFeatureOperation)
        distance = adsk.core.ValueInput.createByReal(5.0)
        extInput.setDistanceExtent(False, distance)
        extInput.isSolid = True
        ext = extrudes.add(extInput)
        brepBody = ext.bodies.item(0)

        brepBody.attributes.add('BugAttributesComponentFromBody', 'test', 'test')

        attributes = design.findAttributes('BugAttributesComponentFromBody', 'test')

        msg = 'Before component\n'
        for idx, attribute in enumerate(attributes):
            if attribute.parent:
                msg += '{} - {} - OK\n'.format(idx, attribute.name)
            else:
                msg += '{} - {} - PB\n'.format(idx, attribute.name)

        brepBody.createComponent()

        attributes = design.findAttributes('BugAttributesComponentFromBody', 'test')

        msg += '\nAfter component\n'
        for idx, attribute in enumerate(attributes):
            if attribute.parent:
                msg += '{} - {} - OK\n'.format(idx, attribute.name)
            else:
                msg += '{} - {} - PB\n'.format(idx, attribute.name)

        ui.messageBox(msg)

    except:
        if ui:
            ui.messageBox('Failed:\n{}'.format(traceback.format_exc()))

Here is the result:

Thank you.

[BrianEkins · Accepted solution]

This is actually as expected.  Attributes are typically not automatically deleted when the entity they're associated with no longer exists.  In your case, you have a body and add an attribute to it.  The body is then moved into another component.  Essentially, a new body is created and the old one deleted.  The attribute to the old body still exists even though the body is gone.  This is because it's possible that the body will come back.  I can roll the timeline back to a time before the body was copied, then the attribute on the old body will have a parent and the newer attribute on the copied body will fail to get its parent.

This is briefly discussed in the User Manual in the topic on Attributes in the section titled "Getting the Associated Entity".

[JeromeBriot]

Thank you @BrianEkins 

After a good sleep, I remembered that I replied the exact same answer in a previous discussion: Orphan Attributes!

I guess this discussion deserves a high rank in the forum blooper. 🤣