epic_score/add_score.lua

local update_formspec = function(meta)
	local amount = meta:get_int("amount")
	meta:set_string("infotext", "Add score block: " .. amount .. " points")

	meta:set_string("formspec", "size[8,2;]" ..
		-- col 1
		"field[0.2,0.5;8,1;amount;Amount;" .. amount .. "]" ..

		-- col 2
		"button_exit[0.1,1.5;8,1;save;Save]" ..
		"")
end

minetest.register_node("epic_score:add", {
	description = "Epic score add block",
	tiles = {
		"epic_node_bg.png",
		"epic_node_bg.png",
		"epic_node_bg.png",
		"epic_node_bg.png",
		"epic_node_bg.png",
		"epic_node_bg.png^epic_dollar.png",
	},
	paramtype2 = "facedir",
	groups = {cracky=3,oddly_breakable_by_hand=3,epic=1},
	on_rotate = screwdriver.rotate_simple,

	on_construct = function(pos)
    local meta = minetest.get_meta(pos)
		meta:set_int("amount", 1)
    update_formspec(meta, pos)
  end,

  on_receive_fields = function(pos, _, fields, sender)
    local meta = minetest.get_meta(pos);

		if not sender or minetest.is_protected(pos, sender:get_player_name()) then
			-- not allowed
			return
		end

    if fields.save then
      local amount = tonumber(fields.amount or "1")
			meta:set_int("amount", amount)
			update_formspec(meta, pos)
    end

  end,

	epic = {
    on_enter = function(_, meta, player, ctx)
      local player_meta = player:get_meta()
      local add_amount = meta:get_int("amount")
      local score = player_meta:get_int("epic_score")
      score = score + add_amount
      player_meta:set_int("epic_score", score)

      ctx.next()
    end
  }
})