Vim NERDTree: show only .txt files?

Question

Using NERDTree plugin, I want to view only *.txt files. There is a NERDTreeIgnore variable, but I want something like NERDTreeWhitelistFilter.

Is there a way to whitelist what I see?

Answer 1

I've been playing around with this — it's an interesting problem. Maybe you could try out this regular expression for ignoring files?

Edit: talked with my co-worker. Here's the correct regular expression (my original one matched "txt" at the beginning of a file name, too).

^(?!.*\.txt$).*

Answer 2

This is what you want:

:let NERDTreeIgnore += ['\(\.txt\)\@<!$[[file]]']