🌿 vim-fern

Split windows (netrw style)
^{nerdfont.vim / glyph-palette.vim / fern-renderer-nerdfont.vim / fern-git-status.vim}

Project drawer (NERDTree style)
^{nerdfont.vim / glyph-palette.vim / fern-renderer-nerdfont.vim / fern-git-status.vim}

^{See Screenshots for more screenshots.}

Fern (furn) is a general purpose asynchronous tree viewer written in pure Vim script.

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🔍 Click here to find fern plugins 🔍

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Concept

• Supports both Vim and Neovim without any external dependencies
• Support split windows and project drawer explained in this article
• Provide features as actions so that user don't have to remember mappings
• Make operation asynchronous as much as possible to keep latency
• User experience is more important than simplicity (maintainability)
• Customizability is less important than simplicity (maintainability)
• Easy to create 3rd party plugins to support any kind of trees

Installation

vim-fern has no extra dependencies so use your favorite Vim plugin manager or see How to install page for detail.

• If you use Neovim < 0.8, you SHOULD add antoinemadec/FixCursorHold.nvim (See #120)

Usage

Command (Split windows)

Open fern on a current working directory by:

:Fern .

Or open fern on a parent directory of a current buffer by:

:Fern %:h

Or open fern on a current working directory with a current buffer focused by:

:Fern . -reveal=%

The following options are available for fern viewer.

Option	Default	Description
-opener	edit	An opener to open the buffer. See :help fern-opener for detail.
-reveal		Recursively expand branches and focus the node. See :help fern-reveal for detail.
-stay		Stay focus on the window where the command has called.
-wait		Wait synchronously until the fern viewer become ready.

:Fern {url} [-opener={opener}] [-reveal={reveal}] [-stay] [-wait]

Command (Project drawer)

All usage above open fern as split windows style. To open fern as project drawer style, use -drawer option like:

:Fern . -drawer

A fern window with project drawer style always appeared to the most left side of Vim and behaviors of some mappings/actions are slightly modified (e.g. a buffer in the next window will be used as an anchor buffer in a project drawer style to open a new buffer.)

Note that additional to the all options available for split windows style, project drawer style enables the following options:

Option	Default	Description
-width	30	The width of the project drawer window
-keep		Disable to quit Vim when there is only one project drawer buffer
-toggle		Close existing project drawer rather than focus

:Fern {url} -drawer [-opener={opener}] [-reveal={reveal}] [-stay] [-wait] [-width=30] [-keep] [-toggle]

Actions

To execute actions, hit a on a fern buffer and input an action to perform. To see all actions available, hit ? or execute help action then all available actions will be listed.

Window selector

The open:select action open a prompt to visually select window to open a node. This feature is strongly inspired by t9md/vim-choosewin.

Renamer action (A.k.a exrename)

The rename action open a new buffer with path of selected nodes. Users can edit that buffer and :w applies the changes. This feature is strongly inspired by shougo/vimfiler.vim.

Plugins

Users

Most of functionalities are provided as plugins in fern. So visit Github topics of fern-vim-plugin or Plugins page to find fern plugins to satisfy your wants.

For example, following features are provided as official plugins

• Netrw hijack (Use fern as a default file explorer)
• Nerd Fonts integration
• Git integration (show status, touch index, ...)
• Bookmark feature

And lot more!

Developers

Please add fern-vim-plugin topic to your fern plugin. The topic is used to list up 3rd party fern plugins.

Then please add a following badge to indicate that your plugin is for fern.

[![fern plugin](https://img.shields.io/badge/🌿%20fern-plugin-yellowgreen)](https://github.com/lambdalisue/vim-fern)

Customize

Use FileType fern autocmd to execute initialization scripts for fern buffer like:

function! s:init_fern() abort
  " Use 'select' instead of 'edit' for default 'open' action
  nmap <buffer> <Plug>(fern-action-open) <Plug>(fern-action-open:select)
endfunction

augroup fern-custom
  autocmd! *
  autocmd FileType fern call s:init_fern()
augroup END

The FileType autocmd will be invoked AFTER a fern buffer has initialized but BEFORE contents of a buffer become ready. So avoid accessing actual contents in the above function.

See Tips pages to find tips, or write pages to share your tips ;-)

Contribution

Any contribution including documentations are welcome.

Contributors who change codes should install thinca/vim-themis to run tests before complete a PR. PRs which does not pass tests won't be accepted.

License

The code in vim-fern follows MIT license texted in LICENSE. Contributors need to agree that any modifications sent in this repository follow the license.