How to use Hydra without define keymap in `head`

[bangedorrunt]

I'm migrating to hydra from which-key. With the later, I just need define key name and description inside which-key module without having to defining keybinding inside. Is it possible with hydra. Put nil in head's rhs doesn't work because keymap is not activated :(

[haolian9]

seems you just need to bind a no-op to the body. this config might help

      invoke_on_body = true,
      on_enter = function() end,

well, i misread, and now i really dont know what do you want. if you dont want to bind a head, what makes you think you need a hydra?

[anuvyklack]

@babygau can you please provide what particular you want to do with an example? Because now I don't really get what's the problem.

[bangedorrunt]

@haolian9 and @anuvyklack thank you for your response. I'm very sorry if my question is not clear enough. Let's say I wanna make a Telescope keybinding to find files with <Leader>ff. If I use Hydra, this should be:

Hydra({
   name = 'Telescope',
   config = {
      color = 'teal',
      invoke_on_body = true,
   },
   mode = 'n',
   body = '<Leader>f',
   heads = {
      { 'f', cmd 'Telescope find_files' },
      { '<Enter>', cmd 'Telescope', { exit = true, desc = 'list all pickers' } },
      { '<Esc>', nil, { exit = true, nowait = true } },
   }
})

However, I don't want to define keybinding inside Hydra but in other module, so I want something like

Hydra({
   name = 'Telescope',
   config = {
      color = 'teal',
      invoke_on_body = true,
   },
   mode = 'n',
   body = '<Leader>f',
   heads = {
      { 'f', nil },
      { '<Enter>', cmd 'Telescope', { exit = true, desc = 'list all pickers' } },
      { '<Esc>', nil, { exit = true, nowait = true } },
   }
})

-- In `telescope.lua` module

vim.keymap.set({"n"}, "<Leader>ff", "<Cmd>Telescope find_files<CR>", {noremap = true, nowait = true, silent = true})

But if I do as the above example, press <Leader>ff do nothing.

[anuvyklack]

You can consider hydra is a one big keybinding, that's bonded to <Leader>f. You also have another <Leader>ff keymap that invoke Telescope file-finder. So when you press <Leader>f Vim will wait timeoutlen (see :help timeoutlen) seconds for continuation (since you have another longer keymap with the same prefix) and activate hydra. The hydra binds its heads something like (for f head): <Plug>(Hydra2)f and it has nothing in common with <Leader>ff>. The <Leader>f is another keymap, that only activates the hydra. But you can bind one keymap to another using remap keymap option:

Hydra({
   ...
   mode = 'n',
   body = '<Leader>f',
   heads = {
      { 'f', '<Leader>ff', { remap = true } },
      ...
   }
})

-- In `telescope.lua` module

-- No need for `noremap = true` here, since it is the default.
vim.keymap.set({"n"}, "<Leader>ff", "<Cmd>Telescope find_files<CR>")