How to set indent to 4 spaces in nxml-mode?

Question

I wanted to indent my XML files with 4 spaces.
I tried to google it, and found this and this one.
But they seem pretty old and/or didn't help me.

This post is great about how to pretty print XML files, but gives no hint how to set indent to a specific value. How can I do that?

Answer 1

I finally found it in this issue.

(setq nxml-child-indent 4 nxml-attribute-indent 4)