How can folds persist after a session?

[FIREBAT-66]

Feature description

Hello @kevinhwang91 , nvim-ufo folds don't seem to persist after exiting an nvim session. I wanted to ask if you might know how this can be done, because some cursory research led me to attempt to make autocommands in nvim, and this is all I could come up with:

`vim.api.nvim_create_autocmd({ "BufWinLeave" }, {
pattern = { "*" },
desc = "save folds on exit",
command = "mkview",
})

vim.api.nvim_create_autocmd({ "BufWinEnter" }, {
pattern = { "*" },
desc = "load folds on entry",
command = "silent! loadview",
})
`

However, I keep getting errors and am unable to open files after starting nvim:

Describe the solution you'd like

I would like to know if nvim-ufo has a abuilt-in way to save the state of every file with folds so that the next time I open a file, it is folded to the last folded state

Additional context

No response

[c-y-p-e]

AFAIK nvim-ufo does not support saving folds.

Using views is probably the correct way, but saving these automatically requires some finetuning.

I use the following configuration to only save folds for actual file buffers:

local augroup                = vim.api.nvim_create_augroup("config.folds", { clear = true })

-- Only save folds and cursor position in view file
vim.opt.viewoptions          = { "folds", "cursor" }
-- Initialize list of manually excluded filetypes (set in corresponding ftplugin)
vim.g.ignored_view_filetypes = {}

-- Save views automatically
vim.api.nvim_create_autocmd("BufWinLeave", {
  group = augroup,
  pattern = "?*",
  desc = "Save view",
  callback = function(args)
    local buftype = vim.api.nvim_get_option_value("buftype", { buf = args.buf })
    local filetype = vim.api.nvim_get_option_value("filetype", { buf = args.buf })
    if buftype == "" and filetype ~= ""                                       -- check if real file buffer
        and not string.match(vim.api.nvim_buf_get_name(args.buf), "^/tmp")    -- check if not a temp file
        and not vim.tbl_contains(vim.g.ignored_view_filetypes, filetype) then -- check if not explicitly excluded
      vim.cmd.mkview({ mods = { emsg_silent = true } })
    end
  end
})

-- Restore views automatically
vim.api.nvim_create_autocmd("BufWinEnter", {
  group = augroup,
  pattern = "?*",
  desc = "Restore view",
  command = "silent! loadview"
})

[GasparVardanyan]

I store sessions with mksession and I have autocmd to load sessions when I cd to a directory.
ufo doesn't recognize the folds loaded from the session. neither K works on folds nor fold_virt_text_handler is being used.