vim / NERDtree / folding - can it remember the state of folds?

Question

Is there a way to make NERDtree remember the state of folds when switching from buffer to buffer?

Here the my complete .vimrc:

set ignorecase
set scs
let perl_fold=1
hi Folded cterm=bold ctermfg=yellow ctermbg=lightblue
set modeline

cabbr N NERDTree

Here is what I am observing:

• start NERDTree
• select a file and use spacebar to open it in a new buffer (all folds are closed)
• open some folds in the buffer
• C-w w back to NERDTree
• select a different file, use spacebar to open it
• C-w w back to NERDTree
• select the first file, hit spacebar

The folds I had opened originally are now closed. I am editing perl files,so the perl_fold=1 is in force. I'd like the state of the folds to be remembered as I bounce around from file to file.

Answer 1

Are you sure about the <Space> mapping? I don't see it listed in NERDTree's help.

Anyway, NERDTree has nothing to do with your buffers content or state, it's only a file explorer.

Without some mechanism to keep state of your buffers your folds are lost when you open a new file. Luckily you can add set hidden to your .vimrc.

With it buffers are kept around until you explicitly delete them with :bd. This means that you still have your folds when going back to your previous file, either by using NERDTree or by using :b <Tab>.

The Vim wiki has nice pages about buffers.