RegisterServerEvent('XD')
AddEventHandler('XD', function()
print(source)
end)
TriggerServerEvent("XD")
is there a way to spoof your source from the server when you trigger an event.
i though of doing this when you trigger
TriggerServerEvent("XD", source = '200' -- [[this is the source the server will think you are]])
Lua is a language of reference. If Lua cannot see something, it cannot use it.
Typically, as a rule of thumb: if you do not define the variable, you cannot use it. There are exceptions to this, which are the functions that the global variable provides to you, like print.
We also see another issue: you try to define source like a table, but you don't give it a table to rest in.
There are two ways to solve this problem.
#1. Give source it's own argument
Remove source and add source as a argument to function(...)
Server:
RegisterServerEvent('XD')
AddEventHandler('XD', function(source)
print(source)
end)
Client:
TriggerServerEvent("XD", '200')
#2. Create a table for source to hang out in
To start with, give the TriggerServerEvent a nice cozy table.
TriggerServerEvent("XD", {} )
Then put source into it.
TriggerServerEvent("XD", { source = '200' })
Now, on the server, we need an argument for the table:
RegisterServerEvent('XD')
AddEventHandler('XD', function(args)
print(args)
end)
However, since args is a table, and we want source, we have to index it.
RegisterServerEvent('XD')
AddEventHandler('XD', function(args)
print(args.source) -- or args["source"]
end)
Related
Actually I am writting a programming language in Lua. It was quite fun. I've wrote a bit of standard library (stack op and simple io). Then I've thought about labels. It would look like in assembly. While and for loop aren't funny in any bit so programming in that language can be quite challenging. Here are some requirements for this system:
Label stack (or array, dictionary) must be accessible from global context.
Jump instruction handler will be in separate file.
This is how my label-handling function look like:
function handleLabel(name,currentLine)
end
I have no idea how to implement this kind of magic. First I've thought about that:
LabelLineIDS = {}
Labels = {}
Labelamount = 1;
function handleLabel(name,currentLine)
LabelLineIDS[Labelamount]=currentline
Labels[Labelamount]=name
Labelamount=Labelamount+1
end
-- In file "jump.lua":
local function has_value (tab, val)
for index, value in ipairs(tab) do
if value == val then
return index
end
end
print ("Error: Label not defined.") -- Bail out.
os.exit(1)
end
local function _onlabel()
local labelName = globalparams --Globalparams variable contain parameters to each function, at the moment
--this will contain label name. It _can_ be nil.
return LabelLineIDS[has_value(Labels, labelName)]
end
CurrLine = _onlabel() --Currline - current line that get's parsed.
--1 command per one line.
But I'm unsure is this well written or even work. Can you give me idea how to parse labels in my programming language (and write jump functions)? Or if my code is pretty ok at the moment, can you help me to improve it?
Using line counter in my parser I've decided to implement gotos like we can see in BASIC. Thanks everyone for help.
I want to call another lua script from my main script say like
session:execute("lua","/path/somefile.lua "..somearg1.." "..somearg2..)
its working fine and somefile.lua is executing but suppose i also want to use session there i.e. i am accessing a database in somefile.lua and want to speak a query result in somefile.lua by using session. (session:speak(queryResult)).
i also tried sending session as one of argument
session:execute("lua","/path/somefile.lua "..session)
but it gives a error "attempt to concatenate global 'session' (a userdata value)"
any advise..??
code of first lua file
session:answer();
session:setAutoHangup(false);
session:set_tts_params("flite","kal");
callerId = session:getVariable("caller_id_number");
session:execute("lua ","/etc/freeswitch/scripts/checkbal.lua "..callerId.." "..session);
session:destroy();
code for 2nd lua file
callerId=argv[1];
session=argv[2];
luasql = require "luasql.postgres";
env=assert(luasql:postgres());
con=assert(env:connect("mydb","postgres","password","127.0.0.1","5432"));
cur=assert(con:execute("select balance from bal where number='"..callerId.."'"));
session:set_tts_params("flite","kal");
row=cur:fetch({},"a");
res=row.balance;
session:speak(res);
Rig your second file to be a module that returns a function or a table of functions. Here is an example that has second file return a "speak" function that you can then re-use as many times as desired:
Code of first Lua file:
session:answer()
session:setAutoHangup(false)
session:set_tts_params("flite","kal")
callerId = session:getVariable("caller_id_number")
speak = require 'checkbal'
speak(session, callerId)
-- session:execute("lua ","/etc/freeswitch/scripts/checkbal.lua "..callerId.." "..session)
session:destroy()
Code for 2nd Lua file:
luasql = require "luasql.postgres"
local env=assert(luasql:postgres())
local con=assert(env:connect("mydb","postgres","password","127.0.0.1","5432"))
local function speak(session, callerId)
local cur = assert(con:execute("select balance from bal where number='"..callerId.."'"))
session:set_tts_params("flite","kal")
row=cur:fetch({},"a")
res=row.balance
session:speak(res)
end
return speak
Note: this is Lua: no need for semicolons.
I would consider making "session" an object (table with methods) with a "speak" method, but this is going beyond scope of this question and is not necessary, may just lead to more maintainable code later.
It is my understanding that in Lua 5.2 that environments are stored in upvalues named _ENV. This has made it really confusing for me to modify the environment of a chunk before running it, but after loading it.
I would like to load a file with some functions and use the chunk to inject those functions into various environments. Example:
chunk = loadfile( "file" )
-- Inject chunk's definitions
chunk._ENV = someTable -- imaginary syntax
chunk( )
chunk._ENV = someOtherTable
chunk( )
Is this possible from within Lua? The only examples I can find of modifying this upvalue are with the C api (another example from C api), but I am trying to do this from within Lua. Is this possible?
Edit: I'm unsure of accepting answers using the debug library. The docs state that the functions may be slow. I'm doing this for efficiency so that entire chunks don't have to be parsed from strings (or a file, even worse) just to inject variable definitions into various environments.
Edit: Looks like this is impossible: Recreating setfenv() in Lua 5.2
Edit: I suppose the best way for me to do this is to bind a C function that can modify the environment. Though this is a much more annoying way of going about it.
Edit: I believe a more natural way to do this would be to load all chunks into separate environments. These can be "inherited" by any other environment by setting a metatable that refers to a global copy of a chunk. This does not require any upvalue modification post-load, but still allows for multiple environments with those function definitions.
The simplest way to allow a chunk to be run in different environments is to make this explicit and have it receive an environment. Adding this line at the top of the chunk achieves this:
_ENV=...
Now you can call chunk(env1) and later chunk(env2) at your pleasure.
There, no debug magic with upvalues.
Although it will be clear if your chunk contains that line, you can add it at load time, by writing a suitable reader function that first sends that line and then the contents of the file.
I do not understand why you want to avoid using the debug library, while you are happy to use a C function (neither is possible in a sandbox.)
It can be done using debug.upvaluejoin:
function newEnvForChunk(chunk, index)
local newEnv = {}
local function source() return newEnv end
debug.upvaluejoin(chunk, 1, source, 1)
if index then setmetatable(newEnv, {__index=index}) end
return newEnv
end
Now load any chunk like this:
local myChunk = load "print(x)"
It will initially inherit the enclosing _ENV. Now give it a new one:
local newEnv = newEnvForChunk(myChunk, _ENV)
and insert a value for 'x':
newEnv.x = 99
Now when you run the chunk, it should see the value for x:
myChunk()
=> 99
If you don't want to modify your chunk (per LHF's great answer) here are two alternatives:
Set up a blank environment, then dynamically change its environment to yours
function compile(code)
local meta = {}
local env = setmetatable({},meta)
return {meta=meta, f=load('return '..code, nil, nil, env)}
end
function eval(block, scope)
block.meta.__index=scope
return block.f()
end
local block = compile('a + b * c')
print(eval(block, {a=1, b=2, c=3})) --> 7
print(eval(block, {a=2, b=3, c=4})) --> 14
Set up a blank environment, and re-set its values with your own each time
function compile(code)
local env = {}
return {env=env, f=load('return '..code, nil, nil, env)}
end
function eval(block, scope)
for k,_ in pairs(block.env) do block.env[k]=nil end
for k,v in pairs(scope) do block.env[k]=v end
return block.f()
end
local block = compile('a + b * c')
print(eval(block, {a=1, b=2, c=3})) --> 7
print(eval(block, {a=2, b=3, c=4})) --> 14
Note that if micro-optimizations matter, the first option is about 2✕ as slow as the _ENV=... answer, while the second options is about 8–9✕ as slow.
I have a WoW/LUA script that I am attempting to start, but it seems to conflict with the Stubby addon, which is a part of the Auctioneer addon, I believe. Here is the message I receive:
Error occured in: Stubby Count: 1 Message: Error: Original call failed
after running hooks for: ChatFrame_OnEvent Usage:
SendChatMessage(text [,type] [,language] [,targetPlayer]) Debug:
(tail call): ? [string ":OnEvent"]:1:
[string ":OnEvent"]:1
Now, the only thing that's happening in the conflicting addon is:
ChatFrame_AddMessageEventFilter("CHAT_MSG_PARTY", partyMsg)
The code within partyMsg is very simple as well:
local function partyMsg(msg,author,language,lineID,senderGUID)
if (store ~= msg) then
SendChatMessage(msg,"SAY",nil,nil);
end
store = msg;
end
Is this error due to two addons both trying to filter the chat frame? If so, how can this be done? It seems odd to me that Blizzard would have such a simple and yet important concept limited to one addon.
I think I see what happened here.
The reference you were using, Events/Communication, shows only the specific parameters for a particular event, regardless of context.
The context is usually an OnEvent handler.
The ChatFrame_AddMessageEventFilter function lets you use the chat frame's OnEvent handler instead of your own for chat frame events, and has well defined parameters for filters you add.
An OnEvent handler might look like:
function Foo_OnEvent(self, event, ...)
A 'ChatFrame' filter must look like this, for the first two parameters:
function Foo_ChatFrameFilter(self, event, msg, ...)
The ChatFrame filter is specific. For OnEvent however, you can make a Lua 'handler' that doesnt care about what frame it came from:
<OnEvent>
MyEventHandler(event, ...)
</OnEvent>
For the sake of completion, I will include the entire source of this addon:
local function partyMsg(someTable,msgType,msg,user,language,...)
if (store ~= msg) then
SendChatMessage(user .. " just said: ".. msg .. " using that sneaky " .. language .. " language.");
end
store = msg;
return false;
end
ChatFrame_AddMessageEventFilter("CHAT_MSG_PARTY", partyMsg)
ChatFrame_AddMessageEventFilter("CHAT_MSG_PARTY_LEADER",partyMsg)
There were a couple issues with the original code:
1) I was using WoWWiki to get my information, and first, I read it incorrectly. lineID and senderGUID are not the 4th and 5th arguments. Then, beyond this, WoWWiki is incorrect on this page in general. The correct arguments are listed above in the source. The first argument, a table, I am unsure of its purpose. In any case, this code now works fully.
I have a function :it's load a file data and build a table.
I want to load the file only once , everytime call the function and get return table in memory,don't load file again(you know io operation repeat is bad).
the goal is just like static field in java,only build once , and use it .
how to do ?
You can do this in one of several ways. For example:
local myInternalLocal = nil
function FuncName(...)
if(not myInternalLocal) then
myInternalLocal = --Do stuff that builds the table.
end
return myInternalLocal
end
Alternatively, you can do it by replacement, which better hides the internal variable, and is (very slightly) faster:
function FuncName(...)
local myInternalLocal = --Do stuff that builds the table.
FuncName = function()
return myInternalLocal
end
end
The downside here has to do with modules. If this is inside of a module, then you may need to change how it rebinds the function. And of course, if someone stores the old function before calling it, they can keep calling the original version.
I think you want to use require to load the file.