Automatic naming of linked bodies (instance naming vs source naming)

[gntech]

Is it possible to get automatic naming of linked bodies so that the name of the links follow the source in some way?

For example, I have made a part that I call "Beam" and then I create a link to that part using alt+drag method. I would then like that the links get a name that shows the connection with the source part like "Instance name (Beam)". And if I chose to rename the source part to Truss then the linked instance will change its name to "Instance name (Truss)"

OS: KDE neon User Edition 5.17 (KDE//usr/share/xsessions/plasma)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.18714 (Git) AppImage
Build type: Release
Branch: master
Hash: a7ad04ba4aefb486fbc5e7c68da3dd488443b08c
Python version: 3.7.3
Qt version: 5.12.5
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: Swedish/Sweden (sv_SE)

[chrisb]

The label is aware of Expressions. I succeeded in referencing another label, and I can even double it with an expression such as
Box.Label + Box.Label, which seemed to have worked well. However, this has three drawbacks:
- I didn't manage to add a constant string
- The label didn't update automatically
- A recompute crashed FreeCAD
Perhaps you can use a spreadsheet for this.

[gntech]

Below is a mockup of what I am looking for.

The parts are named:

Code: Select all

Instance name (partname)

Instance name is what is changed on a rename. The source partname information is sort of already available, see the red ring.

freecad_name_link.png (58.71 KiB) Viewed 1978 times

[vocx]

...
The parts are named:

Code: Select all

Instance name (partname)

...

I think this was like this some commits ago. Since the App::Link was merged quite a few changes have occurred. I think at some point Links did have the sentence "Link to something" in the tree view. It's after all a stylistic change, because as you notice, the real object is mentioned in the LinkedObject property.

[gntech]

I think it gives a nice overview to be able to see what each part really is directly in the tree. But I realise it is a matter of personal preference.

[Zolko]

Instance name is what is changed on a rename.

No: a FreeCAD object has a Name and a Label. The Name is set at creation time and cannot, ever, be modified. The Label is set identical to Name at creation time, but can be modified later. This is also true for App::Link. If you create an App::Link and then assign a linked object to it, the name of the App::Link — the instance — will be Link, and subsequent links will be called Link001, Link002 .... Whatever the object you assign to it later, you can only change the link's Label. The Label is what appears in the tree, the Name is what is used to access an object (with getObject(obj.Name) )

If you want to set the Name of the App::Link instance, you first have to select the object you want to link and then create the link to that object with the Name of the link instance set to the object's Name.

[gntech]

Thanks for the clarification! So the name can be considered an unique identifier of the part or link. And the label is the user given "name".

[vocx]

Thanks for the clarification! So the name can be considered an unique identifier of the part or link. And the label is the user given "name".

Yes. Every "DocumentObject", objects that you see in the tree view, must have a unique Name. If you try to name another object with that same name, its name will be incremented by a counter, like Solid and Sollid001. Names only support alphanumeric characters and the underscore.

The Label is the user defined name, and can use special unicode characters, like spaces and accented letters. There is a preference that controls whether the label can be repeated or not. By default labels cannot be repeated, so they are also incremented numerically if the same Label is used.