Dynamic node with user input

[uyha]

I'm trying to follow https://github.com/L3MON4D3/LuaSnip/wiki/Misc#dynamicnode-with-user-input to create an expansible snippet. Here is what I have

local ls = require("luasnip")
local c = ls.choice_node
local d = ls.dynamic_node
local f = ls.function_node
local i = ls.insert_node
local r = ls.restore_node
local s = ls.snippet
local sn = ls.snippet_node
local t = ls.text_node
local fmt = function(format, args, opts)
  opts = vim.tbl_extend("force", { repeat_duplicates = true }, opts or {})
  return require("luasnip.extras.fmt").fmt(format, args, opts)
end
local lambda = require("luasnip.extras").l
---@diagnostic disable-next-line: unused-local
local rp = require("luasnip.extras").rep
local postfix = require("luasnip.extras.postfix").postfix

vim.keymap.set(
  { "i", "s" },
  "<C-e>",
  function()
        local current_node = ls.session.current_nodes[vim.api.nvim_get_current_buf()]
        local dynamic_node = current_node
        while not dynamic_node.dynamicNode do
          dynamic_node = dynamic_node.parent
        end
        dynamic_node = dynamic_node.dynamicNode

        local func = dynamic_node.user_args.callback
        if func then func() end

        dynamic_node.last_args = nil
        dynamic_node:update()
  end
)

ls.add_snippets("text", {
  s(
    "recurse",
    fmt(
      [[
      command({})
      ]],
      {
        d(1, function(_, _, old_state, _)
          local nodes = old_state and old_state.nodes or {}
          local pos = #nodes + 1
          table.insert(nodes, i(pos, pos == 1 and "here" or ", here"))

          local node = sn(nil, nodes)
          node.old_state = { nodes = nodes }

          return node
        end, nil, { user_args = { callback = function() end } }),
      }
    )
  ),
})

I stripped the out the part that's responsible for restoring mode and cursor position since I haven't gotten to it. I would like to make the recurse snippet when expaded, more nodes can be inserted inside the parentheses after <C-e> is pressed. However, with the above snippet, this error occurs luasnip/nodes/insertNode.lua:283: attempt to index field 'mark' (a nil value). What am I doing wrong here?

[L3MON4D3]

Oh, I think adding a node to multiple snippets, like that function is doing via old_state is not supported at all, at least I haven't paid any mind to that possibility when implementing.

Better use restoreNode for conserving input across updates

[L3MON4D3]

https://github.com/L3MON4D3/Dotfiles/blob/505d92fe9092443f8ceeeaec58b08a8bede9b246/.config/nvim/luasnippets/tex.lua#L99-L109
and https://github.com/L3MON4D3/Dotfiles/blob/505d92fe9092443f8ceeeaec58b08a8bede9b246/.config/nvim/luasnippets/tex.lua#L16-L36

[uyha]

so this is what I have now

vim.keymap.set(
  { "i", "s" },
  "<C-e>",
  function()
      local current_node = ls.session.current_nodes[vim.api.nvim_get_current_buf()]
      local dyn_node = current_node
      while not dyn_node.dynamicNode do
        dyn_node = dyn_node.parent
      end
      dyn_node = dyn_node.dynamicNode

      local fn = dyn_node.user_args[1]
      fn(dyn_node.parent.user_state)
      dyn_node.last_args = nil
      dyn_node:update()
  end
)

ls.add_snippets("text", {
  s(
    "recurse",
    fmt(
      [[
      command({})
      ]],
      {
        d(
          1,
          function(_, parent)
            local count = parent.user_state and parent.user_state.count or 1

            local nodes = {}
            for index = 1, count do
              table.insert(nodes, i(index, index == 1 and "here" or ", here"))
            end

            parent.user_state = { count = count }

            return sn(nil, nodes)
          end,
          nil,
          {
            user_args = {
              function(user_state) user_state.count = user_state.count + 1 end,
            },
          }
        ),
      }
    )
  ),
})

It works when I press <C-e> the first time, but the second time, it reports dyn_node being nil on while not dyn_node.dynamicNode line. Both times the cursor is at the first insert node.

[L3MON4D3]

Ah, you also have to set the current node again, check the last few lines of the function in the wiki

[uyha]

awesome, so the minial snippet to have expand dynamic node with user input is

vim.keymap.set(
  { "i", "s" },
  "<C-e>",
  function()
      local current_node = ls.session.current_nodes[vim.api.nvim_get_current_buf()]
      local dyn_node = current_node
      while not dyn_node.dynamicNode do
        dyn_node = dyn_node.parent
      end
      dyn_node = dyn_node.dynamicNode

      local fn = dyn_node.user_args[1]
      fn(dyn_node.parent.user_state)
      dyn_node.last_args = nil
      dyn_node:update()
      ls.session.current_nodes[vim.api.nvim_get_current_buf()] = dyn_node.snip:jump_into(1)
  end
)

ls.add_snippets("text", {
  s(
    "recurse",
    fmt(
      [[
      command({})
      ]],
      {
        d(
          1,
          function(_, parent)
            local count = parent.user_state and parent.user_state.count or 1

            local nodes = {}
            for index = 1, count do
              table.insert(nodes, i(index, index == 1 and "here" or ", here"))
            end

            parent.user_state = { count = count }

            return sn(nil, nodes)
          end,
          nil,
          {
            user_args = {
              function(user_state) user_state.count = user_state.count + 1 end,
            },
          }
        ),
      }
    )
  ),
})

[L3MON4D3]

If it works👌 :D
But staying at the same position is pretty cool, consider amending it

[uyha]

oh no, I just want a minimal example to start playing around with it. That’s why I didn’t do anything about cursor position and stuff. But thank you for your help.

[L3MON4D3]

Ahh alright that makes sense👍