Conversion in Lua: How to display multiple changed files on disk in Vim?

Question

Related to this post How to display multiple changed files on disk in Vim?,

I want to implement this feature in Lua. Some help would be appreciated.

set autoread
autocmd FocusGained,BufEnter,CursorHold,CursorHoldI *
  \ if mode() !~ '\v(c|r.?|!|t)' && getcmdwintype() == '' | checktime | endif

let g:filechanged_timer = 0
let g:filechanged = ""

function! FileChangedCallback(timer)
  echohl WarningMsg
  echo "File " . g:filechanged . " changed on disk. Buffer reloaded."
  echohl None

  " Reset the timer and the list of files:
  let g:filechanged_timer = 0
  let g:filechanged = ""
endfunction

function! FileChanged(path)
  if g:filechanged_timer == 0
    " First change detected
    let g:filechanged = a:path
    " Wait 0.1 seconds for a new changes to come:
    let g:filechanged_timer = timer_start(100, 'FileChangedCallback')
  else
    " Some more change detected
    " Add the file path to the list:
    let g:filechanged = g:filechanged .. ', ' .. a:path
  endif
endfunction

autocmd! FileChangedShellPost * call FileChanged(expand('<afile>'))

Answer 1

Here is a lua version of the same:

vim.g.filechanged = ""

function FileChangedCallback()
    vim.api.nvim_command([[
        echohl WarningMsg
        echom "File " . g:filechanged . " changed on disk. Buffer reloaded."
        echohl None
        ]])
end

function FileChanged(path)
    if vim.g.filechanged == "" then
        vim.g.filechanged = path
        vim.defer_fn(FileChangedCallback, 100)
    else
        vim.g.filechanged = vim.g.filechanged .. ' ' .. path
    end
end

vim.o.autoread = 1

vim.api.nvim_create_autocmd({'FocusGained', 'BufEnter', 'CursorHold', 'CursorHoldI'}, { callback = function()
    if not string.match(vim.fn.mode(), '^(c|r.?|!|t)') and vim.api.nvim_eval('getcmdwintype()') == '' then
        vim.cmd([[checktime]])
    end
end
})

vim.api.nvim_create_autocmd({'FileChangedShellPost'}, { callback = function()
    FileChanged(vim.fn.expand('<afile>'))
end
})