feature: filetype-specific Lazy-key-mappings

[chrisgrieser]

Did you check the docs?

• [X] I have read all the lazy.nvim docs

Is your feature request related to a problem? Please describe.

The keys from lazy's plugin spec allows for a very concise definition of keymappings with lazy-loading. However, when it comes to filetype-specific keymaps, there is quite a bit of boilerplate:

{
    "iamcco/markdown-preview.nvim",
    lazy = true,
    init = function()
        vim.api.nvim_create_autocmd("FileType", {
            pattern = "markdown",
            callback = function()
                vim.keymap.set("n", "<C-r>", "<Plug>MarkdownPreview", { buffer = true })
            end,
        })
    end,
},

Describe the solution you'd like

Adding a ft key to the Lazy Key Mappings would remove the boilerplate and result in a much cleaner config. It should fit well with lazy's style of configuring things:

{
    "iamcco/markdown-preview.nvim",
    keys = {
        { "<D-r>", "<Plug>MarkdownPreview", ft = "markdown" },
    },
},

Describe alternatives you've considered

As a workaround, I basically created my own small utility function. reduces boilerplate a bit, but still not a great solution, I guess.

Additional context

No response

[folke]

Good idea. Just added this.

[dpetka2001]

I really like this feature. I have a sidenote question. How can you make which-key aware of the new prefix name. Example I currently have in my config

  {
    "toppair/peek.nvim",
    build = "deno task --quiet build:fast",
    keys = {
      {
        "<leader>pp",
        function()
          local peek = require("peek")
          if peek.is_open() then
            peek.close()
          else
            peek.open()
          end
        end,
        desc = "Peek (Markdown Preview)",
        ft = "markdown",
      },
    },
    opts = { theme = "dark" },
  },
  {
    "folke/which-key.nvim",
    opts = {
      defaults = {
        ["<leader>p"] = { name = "+peek" },
      },
    },
  },

which without the ft = "markdown it correctly registers the <leader>p prefix name correctly, but when ft is present in the keys section, then which-key shows when I press <leader> the following: p -> +prefix and it doesn't register correctly the which-key prefix name. Is there any work around to this?

[folke]

@dpetka2001 that's a bug in which-key. I think there's a PR open to fix that (by reverting another PR). Need to look at it :)

[dpetka2001]

For the moment, as a work around, I added ft = "markdown for the plugin itself and then added in the init function the following

    init = function()
      require("lazyvim.util").on_load("which-key.nvim", function()
        require("which-key").register({
          ["<leader>p"] = { name = "+peek" },
        })
      end)
    end,

which seems to do the trick for the time being, while maintaining the ft also in the keys section to only register the key when in Markdown files.

Edit: of course that snippet is Lazyvim specific, in case anyone tries to incorporate it in his own custom config with only lazy.nvim and which-key.

[MarcoBuess]

@folke Was the which-key bug ever adressed? I'm still seeing this issue.

[dpetka2001]

As far as I'm aware, it hasn't been addressed yet. But there's a workaround for it in this issue comment until it gets resolved.

[MarcoBuess]

Lets put the reference here in case anyone else comes across this: folke/which-key.nvim#514