How to reach the stroke information via .jsx

Hi ALL.
Do you have any idea how to reach the stroke information?

I know, the basic stroke attributes are stored in the executeActionGet(r).getString(stringIDToTypeID('layerSVGdata'), but the advanced attributes, like stroke-linecap or dash, and the others are not.
When I use Layer menu / copy SVG, than there are all these informations, and I figured how to reach that menu with JSX, but it is impossible to reach the clipboard via jsx scripting.
So I need to find another solution, but I did not yet.

Do you or anyone has any idea?
Thanks a lot