Glua error "attempt to call method 'GetPlayerVisible' (a nil value)" - lua

I personally don't know how a built in function can be indexed as "nil" butthis error appeared and it haulted my nextbot's movement. heres my code that is causing this
if (!self:GetPlayerVisible() and chasing_timer > chasing_time) then
self.stopchasing = true
self.enraged = false
print("Chase stopped")
print("Increasing escaped chases count, new:", self.escapedchases)
self.escapedchases = self.escapedchases + 1
end
I tried replacing the "!" with "not" but it did nothing.

I don't know what self is but that table does not contain an element GetPlayerVisible. Hece you may not call it. Calling nil values doesn't make sense.
Ask yourself why you think this function exists. Typical reasons are typos, indexing the wrong table or not having implemented a function yet.
To avoid this error you basically have two options. Make sure you call something that exists, or don't call it.

Related

roblox LUA Expected 'end' (to close 'than' at line 3), got '='

function teleportTo(placeCFrame)
local plyr = game.Players.LocalPlayer;
if plyr.Character then
return plyr.Character.HumanoidRootPart.CFrame = placeCFrame;
end
end
teleportTo(game:GetService("Workspace").game:GetService("Workspace").Zeppelin.FuelTank1.Tank.CFrame)
my code is here, idk much about coding thanks for helping
and if you told me how to make the player teleport to a moving object it would be so super
The error is telling you what is going on.
When the code was being interpreted line by line, it expected the next symbol to be end, but instead it got =.
That means that something about how you're using the equals sign is incorrect. So when we look at the line :
return plyr.Character.HumanoidRootPart.CFrame = placeCFrame
You cannot assign a value on the same line as a return command. return is used to pipe a value out of a function so it can be used where the function was called.
But I'm pretty sure that isn't what you intended, you just want to set a player's position. So to fix your issue, remove the return.
if plyr.Character then
plyr.Character.HumanoidRootPart.CFrame = placeCFrame
end
The reason you are getting an error is because = is usually defined as setting a value, and no code can be executed after a return or it will error
If you wanted to, you could add return after all the code is done executing

How to determine if sysdig field exists or handle error if it doesn't

I'm using Sysdig to capture some events and have a small chisel (LUA script) to capture and format the events as necessary. On the on_init() I'm requesting fields like so :
f_field = chisel.request_field("<field>")
My question is how can I check if a field exists before requesting it? I'm going to use a new field only just released on 0.24.1 but ideally I'd like my chisel to continue to work on older versions of sysdig without this field. I've tried wrapping the call to chisel.request_field in a pcall() like so :
ok, f_field = pcall(chisel.request_field("<field>"))
and even implementing my own "get_field" function :
function get_field(field)
ok, f = pcall(chisel.request_field(field))
if ok then return f else return nil end
end
f_field = get_field("<field>")
if f_field ~= nil then
-- do something
end
but the error ("chisel requesting nonexistent field <field>") persists.
I can't see a way to check if a field exists but I can't seem to handle the error either. I really don't want multiple versions of my scripts if possible.
Thanks
Steve H
You're almost there. Your issue is in how you're using pcall. Pcall takes a function value and any arguments you wish to call that function with. In your example you're passing the result of the request_field function call to pcall. Try this instead..
ok, f = pcall(chisel.request_field, "field")
pcall will call the chisel method with your args in a protected mode and catch any subsequent errors.

gmod GameMode Lua. IsPlayer retuning nill value

I'm trying to make a gmod gamemode. In my init.lua I wanted it so that way team members can't hurt each other. So I used this code
function GM:EntityTakeDamage( target, dmginfo )
if ( target:IsPlayer() and dmginfo:IsPlayer() ) then
if (dmginfo:Team() == target:Team()) then
dmginfo:ScaleDamage( 0.0 ) // Sets damage to 0
end
end
end
However it's giving me the error telling me that IsPlayer() is a nil value even though it should be returning a boolean. It points to no other lines other then the line with IsPlayer() and it's saying it is IsPlayer()
you have a typo in line 3. dminfo
You should narrow down which of your multiple IsPlayer() calls actually is nil
dmgInfo is a CTakeDamageInfo which has no function IsPlayer()
single line Lua comments are opened with --, not //
https://wiki.garrysmod.com/page/Category:CTakeDamageInfo
If you call a function and it says its nil, then check if it even exists. Or even better, check this befor you use the function in the first place.
And to prevent you from coming back in a minute, CTtakeDamageInfo also does not have a function Team() as well.
Check out CTDamageInfo:GetAttacker()

attempt to call a nil value

for i = 1, groupA:getNumChildren() do
local sprite = groupA:getChildAt(i)
if cute.anim[1]:collidesWith(sprite) then
youLoose()
end
end
local function youLoose()
local font3 = TTFont.new("billo.ttf", 20, " 1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ,?")
local text7 = TextField.new(font2, "gameover")
text7:setPosition(200, 100)
stage:addChild(text7)
GameLost = Bitmap.new(Texture.new("gameover.jpg"))
Background : removeFromParent()
groupA : removeFromParent()
stage: addChild(GameLost)
alert()
end
It gives an error that says 'attempt to call global youLoose (a nil value), where am I doing it wrong?
Note that collideswith is not the same as collidesWith; if that error you posted is correct, then you posted code that is different from what you are using. It could be that the method really is called collidesWith (it appears to be if it is the one from sprite1), but you used collideswith. Alternatively, if the code posted is what you used, then the error is likely attempt to call collideswith(a nil value), so cute.anim[1] is not a sprite1 object, but it is not nil either otherwise the error would be different.
Once you have fixed this, you'll notice that youLoose is defined after that for loop, when you call youLoose() it is not yet defined. You're going to have to move the local function youLoose() function to before the loop. Because the loop is not itself in a function, but is at module level, it gets executed before any following code, so any functions (local or global) that are used in the loop must be defined before the loop.
Note that "loose" does not mean the same as "lose". Check Grammar-monster to see difference. Probably everywhere you have the word "loose" you should change to "lose".

Lua arguments passed to function in table are nil

I'm trying to get a handle on how OOP is done in Lua, and I thought I had a simple way to do it but it isn't working and I'm just not seeing the reason. Here's what I'm trying:
Person = { };
function Person:newPerson(inName)
print(inName);
p = { };
p.myName = inName;
function p:sayHello()
print ("Hello, my name is " .. self.myName);
end
return p;
end
Frank = Person.newPerson("Frank");
Frank:sayHello();
FYI, I'm working with the Corona SDK, although I am assuming that doesn't make a difference (except that's where print() comes from I believe). In any case, the part that's killing me is that inName is nil as reported by print(inName)... therefore, myName is obviously set to nil so calls to sayHello() fail (although they work fine if I hardcode a value for myName, which leads me to think the basic structure I'm trying is sound, but I've got to be missing something simple). It looks, as far as I can tell, like the value of inName is not being set when newPerson() is called, but I can't for the life of me figure out why; I don't see why it's not just like any other function call.
Any help would be appreciated. Thanks!
Remember that this:
function Person:newPerson(inName)
Is equivalent to this:
function Person.newPerson(self, inName)
Therefore, when you do this:
Person.newPerson("Frank");
You are passing one parameter to a function that expects two. You probably don't want newPerson to be created with :.
Try
Frank = Person:newPerson("Frank");

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