Lua recursive scrolling menu not working? - recursion

Question

Hey guys, just wondering why ain't my menu working, I've been coding it for like 8 hours now and just can't figure out what's wrong.
Menu = {
label = "Mahin Menu",
current = current or true,
open = open or true,
subMenus = {}
}
function Menu.newSubMenu()
return {
setup = Menu.setup,
print = Menu.print,
toggleOpen = Menu.toggleOpen,
getCurrentMenu = Menu.getCurrentMenu,
getLastMenu = Menu.getLastMenu,
getNextMenu = Menu.getNextMenu,
getPrevMenu = Menu.getPrevMenu
}
end
function Menu:setup(m_parent, m_label, m_action)
self.parent = m_parent
self.label = m_label
self.action = m_action
self.subMenus = {}
self.current = false
self.open = false
table.insert(m_parent.subMenus, self)
end
function Menu:print(indent)
io.write(string.rep(" ", indent))
if #self.subMenus>0 then
if self.open == true then
io.write("[-]")
else
io.write("[+]")
end
else
io.write(" ")
end
if self.current == true then
io.write("<" .. self.label .. ">")
else
io.write(" " .. self.label)
end
io.write("\n")
if #self.subMenus>0 and self.open == true then
for i=1,#self.subMenus do
self.subMenus[i]:print(indent+1)
end
end
end
function Menu:toggleOpen()
if self.open == true then
self.open = false
else
self.open = true
end
end
function Menu:getCurrentMenu()
if self.current == true then
return self
else
for k=1,#self.subMenus do
local v = self.subMenus[k]:getCurrentMenu()
if v ~= nil then
return v
end
end
end
end
function Menu:getLastMenu()
if self.open == true and #self.subMenus > 0 then
return self.subMenus[#self.subMenus]:getLastMenu()
else
return self
end
end
function Menu:getNextMenu(bool)
bool = bool or false
if bool == false then
if #self.subMenus > 0 and self.open == true then
return self.subMenus[1]
end
end
if self.parent then
if self.parent.subMenus[#self.parent.subMenus] == self then
self.parent:getNextMenu(true)
else
for i=1,#self.parent.subMenus do
if self.parent.subMenus[i] == self then
print(self.parent.subMenus[i+1].label)
return self.parent.subMenus[i+1]
end
end
end
else
return self
end
end
function Menu:getPrevMenu()
if self.parent then
for k=1,#self.parent.subMenus do
if self.parent.subMenus[k] == self then
if k == 1 then
return self.parent
elseif #self.parent.subMenus[k-1].subMenus > 0 and self.parent.subMenus[k-1].open == true then
local x = self.parent.subMenus[k-1]
while #x.subMenus > 0 and x.open == true do
x = x.subMenus[#x.subMenus]
end
return x
else
return self.parent.subMenus[k-1]
end
end
end
else
return self
end
end
Test = Menu.newSubMenu()
Test:setup(Menu, "Test item")
Mahi = Menu.newSubMenu()
Mahi:setup(Menu, "Mahi item")
Mahi.open = true
Testx = Menu.newSubMenu()
Testx:setup(Mahi, "Lalall")
Testx.open= true
Sadmad = Menu.newSubMenu()
Sadmad:setup(Testx, "Woot")
Asd = Menu.newSubMenu()
Asd:setup(Menu, "Asd menu")
Asd.current = true
Menu.current = false
repeat
print(string.rep("\n",2))
Menu:print(0)
x=io.read()
if x == "z" then
x = Menu:getCurrentMenu()
print(Menu:getCurrentMenu().label)
print(Menu:getCurrentMenu():getNextMenu().label)
y = Menu:getCurrentMenu():getNextMenu()
x.current = false
y.current = true
elseif x == "a" then
x = Menu:getCurrentMenu()
y = Menu:getCurrentMenu():getPrevMenu()
x.current = false
y.current = true
end
until x == "sad"
"
there's the code, and when ever i try to move my current from "Asd menu" downwards, it'll error:
menu.lua:150: attempt to index a nil value
which doesn't make any sense, it's clearly declared, and I've tried adding prints and they always give me Asd menu O.o
Same goes for if I'll try to move from Woot to Asd menu, same exact error, and I have no idea why, since I added those prints
print(Menu:getCurrentMenu().label)
print(Menu:getCurrentMenu():getNextMenu().label)
and they do give me Asd menu, but then it says that trying to index a nil value at the second print line, but it sill does print? I'm out of ideas, any help out here?

Answer 1

You are missing a return statement in line 92.
Note that this line does not actually return anything, so the function is returning nil.
After changing it to return self.parent:getNextMenu(true) it seems to be working.