Nerdtree is a file explorer for Vim/Neovim. After install, it will generate file navigation windows just like an IDE. We can operate on files easily in the nerdtree window. In this post, I will summarize some of its configurations and usages.

Install

We can use vim-plug to install nerdtree:

Plug 'scrooloose/nerdtree'

Then install this plugin in Nvim using:PlugInstall.

Configuration

In normal mode of Neovim, you can use :NerdTreeToggle to open the nerdtree widows. Nerdtree does not provide a shortcut for this command by default. In order to quickly open or close the file navigation window, we can add a shorcut to this command. For example, imitating the way Sublime Text opens the side bar, we can use this setting:

nnoremap <silent> <C-k><C-B> :NERDTreeToggle<CR>

If you want to open the nerdtree window when opening up Nvim, but put the cursor in the file-editing window, you can use the following setting:

autocmd VimEnter * NERDTree | wincmd p

For more info, see here.

Directory operation

Create child file or dir under a directory

First, move the cursor to the directory, press m(stand for menu), then press a to create a childnode which can be a file or a directory. To create a directory, you need to append / behind the node name. See here for more info.

How to exit a menu?

When you press m to open the file operation menu for a directory, if you do not want to perform any operation, you can press <ESC> or Ctrl-C to exit this menu. See here.

go up one level of directory

To show parent directory of current node, press u.

Change root to the directory where the cursor is

To change the root directory to where the cursor resides, use C.

Open/close child directory of current directory recursively

  • Open recursively:O
  • Close recursively:X

Move the cursor to the first/last node which has the same level with current node

  • Move to first node of same level:K
  • Move to last node of same level: J

A node can be a file or directory.

Move the cursor to the previous/next node which has the same level with current node

  • Move to previous node of same level:Ctrl + k
  • Move to next node of same level:Ctrl + j

File node operations

How to open a file in new Nvim window?

To open file in a new window in vertical direction, use i. To open file in a new window in horizontal direction, use s.

We can also use gi or gs. The function is the same except that the cursor is still in the nerdtree file navigation window. See reference here.

How to rename or move files?

In the nerdtree window, move the cursor to the node which you want rename, then press m. In the opened up menu, press m again. In Neovim window below, you will see prompt to give the path of the new file. Just change the file name.

If you want to move the file, the operation is the same: just input a new path for this file (including the file name).

How to reveal or show current file in nerdtree window

In normal mode, use :NerdTreeFind command to reveal the postion of current file in the file tree. There is no shortcut for this command. According to solution provided here, we can use the following mappings:

nmap <leader>nf :NERDTreeFind<CR>

What is <leader>,see here for an explanation.

Miscellaneous

How to yank the path of a node in nerdtree window

When we are navigating through the nerdtree window, we may want to copy the full path or the relative path of current node. Nerdtree provide a custom function NERDTreeAddKeyMap to achieve what we want.

First, we need to create a file, e.g., mymapping.vim, under the nerdtree install directory. If you are using Neovim and use vim-plug to manage your plugin, the directory is likely ~/.local/share/nvim/plugged/nerdtree/nerdtree_plugin/ or something similar. Anyway, create file mymapping.vim under this directory and edit it.

To yank the full path of node using shortcut yy, we can use the following settings:

call NERDTreeAddKeyMap({
        \ 'key': 'yy',
        \ 'callback': 'NERDTreeYankFullPath',
        \ 'quickhelpText': 'put full path of current node into the default register' })

function! NERDTreeYankFullPath()
    let n = g:NERDTreeFileNode.GetSelected()
    if n != {}
        call setreg('"', n.path.str())
    endif
    call nerdtree#echo("Node full path yanked!")
endfunction

Similarly, to yank the relative path (relative to current root) of current code using yr, we can use the following settings:

call NERDTreeAddKeyMap({
        \ 'key': 'yr',
        \ 'callback': 'NERDTreeYankRelativePath',
        \ 'quickhelpText': 'put relative path of current node into the default register' })


function! NERDTreeYankRelativePath()
    let n = g:NERDTreeFileNode.GetSelected()
    if n != {}
        call setreg('"', fnamemodify(n.path.str(), ':.'))
    endif
    call nerdtree#echo("Node relative path yanked!")
endfunction

For the meaning of fnamemodify(), see here.

Ok, that is all the settings. Then you can use yy/yr to copy the full/relatvie path of node under the cursor when you are in the nerdtree file explorer window.

How ignore files and folders

Nerdtree shows all the files and directories under current root by default. If you want to ignore certain files and folder, e.g., *.pyc file and __pycache__ directory, you can use the following settings:

" the ignore patterns are regular expression strings and seprated by comma
let NERDTreeIgnore = ['\.pyc$', '^__pycache__$']

You can use regular expression for the ignore pattern and separate several pattern by comma.

How to show current root as relative path from $HOME in status bar?

Nerdtree has a setting NERDTreeStatusline for statuslines. Use the following setting in your Nvim config:

let NERDTreeStatusline="%{exists('b:NERDTree')?fnamemodify(b:NERDTree.root.path.str(), ':~'):''}"

I got my inspiration from here, here and also the nerdtree documentation.

References