Minetest Mod: Add written book on join

local my_title = "I'm some kind of demonstation text"
local my_contents = [[This is a demonstration
for multiline contents
the end.]]

-- For testing
--minetest.register_on_joinplayer(function(player)

minetest.register_on_newplayer(function(player)
    local inv = player:get_inventory()
    local book = ItemStack("default:book_written")
    book:get_meta():from_table({
        title = my_title,
        description = my_title,
        owner = "#!SERVER!#",
        text = my_contents,
        page = 1,
        page_max = math.ceil((#my_contents:gsub("[^\n]", "") + 1) / 14)
    })
    inv:add_item("main", book)
end)