So you want to write a neovim plugin with lua
April 6, 2024
I’ve recently been messing around with writing neovim plugins. When I initially got going I found it a little tricky to know how to get started. There’s the official neovim docs which are great; but in my beginner experience exhaustive to the point of slight impenetrability. Beyond that, the thing I found most useful was simply reading the source of some popular plugins to get an idea of how things worked. I would recommend sticking to plugins with a smaller scope though.
As a demostrative MVP (minimal viable plugin) jumping-off-point, I’m going to make a very simple note-taking plugin. It will provide a command to neovim which when run opens a file titled with the date and time in a specific notes directory. Vamos.
This is what you will want your directory structure to look like.
├── lua
│ └── note
│ └── init.lua
└── plugin
└── note.vim
The plugin/note.vim file will look like this.
command! Note lua require("note").main()
This creates a custom command Note which when run will call a lua function.
Now on to where that function and the meat of the plugin logic will live: the lua/note/init.lua file.
With more complex plugins this section will often be split into many files but we’ve just got one here as it’s so simple.
First things first we create a plugin object.
local note = {}
Then we will define some default options for the plugin in a table. These are variables you want the user to be able to change when they call the setup function.
local defaults = {
note_directory = "~/notes/",
date_format = "%Y-%m-%d %H:%M",
file_extension = ".md",
}
Next we need the setup function. This takes the user’s options and merges them with our default options.
function note.setup(user_options)
options = vim.tbl_deep_extend("force", defaults, user_options or {})
end
This is the main function where the magic happens.
function note.main()
local dir = options.note_directory
local name = os.date(options.date_format)
local ext = options.file_extension
local filename = string.format("%s%s%s", dir, name, ext)
local command = string.format("edit %s", filename)
vim.api.nvim_command(command)
end
Finally we return the plugin obect.
return note
At this point you should have a working plugin :) As a little coda, this is how you can use your fancy new plugin using lazy.nvim.
require("lazy").setup({
{
-- local
dir = "~/neovim-note-plugin",
-- github
-- "me/neovim-note-plugin",
-- alternative non github hosting
-- url = "https://git.example.com/me/neovim note-plugin",
config = fucntion()
require("note").setup({
file_extension = ".org",
})
end,
}
})
Hope you’ve enjoyed.