Amazing 'built-in' FC/Sketcher Capability - Try to understand 'mechanism' Copying Sketch recognising edge.Tag !?

[paullee]

Not sure this should just go into Python Script or Here, just feel free to move if found better elsewhere!

I am learning / experimenting with SketchObjectPython. After testing following steps, I am amazed by what FC / Sketcher do without me writing any codes for it - just wonder what supposed to happen and understand FC / Sketcher's behaviour without having to learn C++ etc. to read FC code

Preparation - No.1 - 2 screencaptures below

1. I make 2 SketchObjectPython
2. 1st (ArchSketch_Master) with a Rectangle
3. 2nd (ArchSketch_Dependent) has No geometry
4. 2nd SketchObjectPython has 2 properties

   Code: Select all

         fp.addProperty("App::PropertyStringList","MasterSketchEdgeGroupsAndEdges","ArchSketch Properties","MasterSketch's Edges ")
         obj.addProperty("App::PropertyLink","MasterSketch","Referenced Sketches ","Master Sketch")
   

5. In the PropertyStringList, I copy in Tag of 2 edges in 1st object (ArchSketch_Master)
6. In the PropertyLink, it is linked to the 1st object (ArchSketch_Dependent)

Copying Sketches - No.3 screencaptures below

1. Now, I select the 1st object (ArchSketch_Dependent) ... press Ctrl-C to copy
2. FC ask if I want to copy the dependency...(the 1st ArchSketch_Master)
3. Answer yes, supposedly FC would copy the both SketchObjectPython ...

Amazing Result FC 'tracing' edge.Tag information!? - No.4 screencaptures below

1. Not only a copy of both Objects ... it also make the Copy of 'ArchSketch_Dependent' PropertyLink point to the Copy of 'ArchSketch_Master.'.. that's terrific!
2. ... But MORE! In the Copy of 'ArchSketch_Dependent' PropertyStringList - just thought these string of tags are 'meaningless' to FC - FC 'update' these tags by replacing with the corresponding edges' tag in the 'Copy' of ArchSketch_Master. The 'new' tags are different! .

Just wonder If I mistake myself with observations above? Or I miss something simple? Hope to understand more how FC works here.

Attached the file with simply the 2 SketchObjectPython for testing.

Thanks in advance.

Maybe @abdullah can give some quick insight?

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