# Adding Plugins {#sec-additional-plugins}

To add a new Neovim plugin, use `npins`

Use:

`nix-shell -p npins` or `nix shell nixpkgs#npins`

Then run:

`npins add --name <plugin name> github <owner> <repo> -b <branch>`

Be sure to replace any non-alphanumeric characters with `-` for `--name`

For example 

`npins add --name lazydev-nvim github folke lazydev.nvim -b main`

You can now reference this plugin as a **string**.

```nix
config.vim.startPlugins = ["lazydev-nvim"];
```

## Modular setup options {#sec-modular-setup-options}

Most plugins is initialized with a call to `require('plugin').setup({...})`.

We use a special function that lets you easily add support for such setup
options in a modular way: `mkPluginSetupOption`.

Once you have added the source of the plugin as shown above, you can define the
setup options like this:

```nix
# in modules/.../your-plugin/your-plugin.nix

{lib, ...}:
let
  inherit (lib.types) bool int;
  inherit (lib.nvim.types) mkPluginSetupOption;
in {
  options.vim.your-plugin = {
    setupOpts = mkPluginSetupOption "plugin name" {
      enable_feature_a = mkOption {
        type = bool;
        default = false;
        # ...
      };

      number_option = mkOption {
        type = int;
        default = 3;
        # ...
      };
    };
  };
}
```

```nix
# in modules/.../your-plugin/config.nix
{lib, config, ...}:
let
  cfg = config.vim.your-plugin;
in {
  vim.luaConfigRC = lib.nvim.dag.entryAnywhere ''
    require('plugin-name').setup(${lib.nvim.lua.toLuaObject cfg.setupOpts})
  '';
}
```

This above config will result in this lua script:

```lua
require('plugin-name').setup({
  enable_feature_a = false,
  number_option = 3,
})
```

Now users can set any of the pre-defined option field, and can also add their
own fields!

```nix
# in user's config
{
  vim.your-plugin.setupOpts = {
    enable_feature_a = true;
    number_option = 4;
    another_field = "hello";
    size = { # nested fields work as well
      top = 10;
    };
  };
}
```

## Details of toLuaObject {#sec-details-of-toluaobject}

As you've seen above, `toLuaObject` is used to convert our nix attrSet
`cfg.setupOpts`, into a lua table. Here are some rules of the conversion:

1. nix `null` converts to lua `nil`
2. number and strings convert to their lua counterparts
3. nix attrSet/list convert into lua tables
4. you can write raw lua code using `lib.generators.mkLuaInline`. This function
   is part of nixpkgs.

Example:

```nix
vim.your-plugin.setupOpts = {
  on_init = lib.generators.mkLuaInline ''
    function()
      print('we can write lua!')
    end
  '';
}
```

## Lazy plugins {#sec-lazy-plugins}

If the plugin can be lazy-loaded, `vim.lazy.plugins` should be used to add it.
Lazy plugins are managed by `lz.n`.

```nix
# in modules/.../your-plugin/config.nix
{lib, config, ...}:
let
  cfg = config.vim.your-plugin;
in {
  vim.lazy.plugins.your-plugin = {
    # instead of vim.startPlugins, use this:
    package = "your-plugin";

    # if your plugin uses the `require('your-plugin').setup{...}` pattern
    setupModule = "your-plugin";
    inherit (cfg) setupOpts;

    # events that trigger this plugin to be loaded
    event = ["DirChanged"];
    cmd = ["YourPluginCommand"];

    # keymaps
    keys = [
      # we'll cover this in detail in the keymaps section
      {
        key = "<leader>d";
        mode = "n";
        action = ":YourPluginCommand";
      }
    ];
  };
;
}
```

This results in the following lua code:

```lua
require('lz.n').load({
  {
    "name-of-your-plugin",
    after = function()
      require('your-plugin').setup({--[[ your setupOpts ]]})
    end,

    event = {"DirChanged"},
    cmd = {"YourPluginCommand"},
    keys = {
      {"<leader>d", ":YourPluginCommand", mode = {"n"}},
    },
  }
})
```

A full list of options can be found
[here](https://notashelf.github.io/nvf/options.html#opt-vim.lazy.plugins