Hi,
do we have a function to show all sorting icon including attach header by default after init?
For now, grid can show only one sorting icon at the time, it is by design
you can use setSortImgState API for that
https://docs.dhtmlx.com/api__link__dhtmlxtreegrid_setsortimgstate.html
We are plan to make this functionality more flexible in future.
You can assign a css class to grid, which will add an background image with sorting icon for all cells in the column, though.