Lazy load when VimEnter or edit file

[eeeXun]

I lazy-load nvim-tree with following

use({
    "nvim-tree/nvim-tree.lua",
    cmd = { "NvimTreeOpen", "NvimTreeToggle" },
})

I want load it when enter a directory, ex. nvim ~/

local fn = vim.fn
local autocmd = vim.api.nvim_create_autocmd
autocmd("VimEnter", {
    callback = function()
        if fn.argc() == 1 and fn.isdirectory(fn.argv()[1]) ~= 0 then
            vim.cmd.NvimTreeOpen(fn.argv()[1])
            return true
        end
    end,
})

The above works for me.

I also want load it when edit a directory, ex. :e ~/

local fn = vim.fn
local autocmd = vim.api.nvim_create_autocmd
autocmd("BufAdd", {
    callback = function(data)
        if fn.isdirectory(data.file) ~= 0 then
            vim.cmd.NvimTreeOpen(data.file)
            return true
        end
    end,
})

It works when entering vim with argument (ex. nvim some_file), then :e ~/. nvim-tree open as expected.
But when entering vim without any argument (ex. nvim), so only one buffer ([No Name]) . Then :e ~/, nvim-tree doesn't open.

[alex-courtis]

RE: :e ~/ have you seen :help hijack_directories.enable ? That will open the tree whenever you open a new directory buffer. Of course that will only function after nvim-tree setup has been called.

Honestly, I don't think lazy loading the tree is viable: there will be "race conditions" around events and their ordering.

If you are not lazy loading, you can use the API e.g. require("nvim-tree.api").tree.toggle({ focus = false }) and rely on behaviour like hijack_directories.

[eeeXun]

I somehow get it works by replacing BufAdd with BufEnter.

local fn = vim.fn
local autocmd = vim.api.nvim_create_autocmd
autocmd("VimEnter", {
    callback = function()
        if fn.argc() == 1 and fn.isdirectory(fn.argv()[1]) ~= 0 then
            vim.cmd.NvimTreeOpen(fn.argv()[1])
            return true
        end
    end,
})
autocmd("BufEnter", {
    callback = function(data)
        if fn.isdirectory(data.file) ~= 0 then
            vim.cmd.NvimTreeOpen(data.file)
            return true
        end
    end,
})

[alex-courtis]

I somehow get it works by replacing BufAdd with BufEnter.

That's not surprising; event ordering is practically nondeterministic.

What is you use case for lazy loading on command? nvim-tree does nothing at startup except for loading configuration and registering events - it's very cheap.

[eeeXun]

What is you use case for lazy loading on command? nvim-tree does nothing at startup except for loading configuration and registering events - it's very cheap.

I just do it for cool. I don't have any meaningful reason. packer provide it, and I use it.

[alex-courtis]

Take a look at Open At Startup for some interesting recipes for startup.