lua : passing parameter to other function problem - function

not sure did anyone ever face this kind of problem. here is my code
in main.lua :
local highScore = require("highScore")
local username = "myName"
local finishedTime = 12345
highScore:InsertHighScore(userName, finishedTime)
in highScore.lua
function InsertHighScore(name,time)
print(name)
print(time)
-- other code
end
it look simple and shouldn't be wrong, but in my console out put it show :
table: 0x19e6340
myName
after a day of testing, i found that before the 2 parameter that i pass, it actually passing another table to me, so do these changes on highScore.lua:
function InsertHighScore(table,name,time)
print(table)
print(name)
print(time)
-- other code
end
so now my "other code" can work nicely, but why it pass me a table before my parameter ?

In Lua, a call to an object/table with a colon instead of a dot indicates that the object/table should be passed into the function as the first parameter (e.g, as a self). If you don't care about that, then call the function with a dot instead:
highScore.InsertHighScore(userName, finishedTime)

Related

Retrieving A Function From A WebhookScript Global Variable

In WebhookScript, I can store a function in a variable with:
sub = function(a, b) {
return a - b
}
I'd like to store a function in a Global Variable so that I can use it in multiple Custom Actions. But if I've saved the above function as $sub$ then
sub2 = var('$sub$')
subX = sub(1,2)
causes an error:
Trying to invoke a non-function 'string' # line...
And
function subX(a,b){
var('$sub$')
}
when sub only contains return a - b, doesn't work either.
Obviously I need to convert the string to a function but I'm not sure whether that's possible.
I know this is a bit of an obscure language but if anyone knows how this can be done in similar languages like JavaScript and PHP, I'm happy to test out any guesses...
The solution here is to remove the function section and just enter the script, which inherits the execution scope so if my global variable $script$ is:
return 'hello ' + a
Then I can execute the function with:
a = 'world'
value = exec(var('$script$'))
echo(value)
(credit to Webhook.Site's support team for explaining this)

How to implement a basic Lua function in Conky?

I am trying to add a function to my Conky which prints the length of a string for debug purposes. The code, inside a file called test.lua, is pretty trivial:
function test(word)
return string.len(word)
end
...and I load it like this. In my conky.config section I have:
lua_load = '/home/xvlaze/test.lua',
lua_draw_hook_pre = 'test'
...in the conky.text section I have:
${lua test "fooo"}
...where test is the name of the function and fooo the string to test.
The expected result should be a printed 4 in Conky, but instead of that I get:
conky: llua_do_call: function conky_test execution failed: /home/xvlaze/test.lua:2: attempt to index a nil value (local 'string')
conky: llua_getstring: function conky_test didn't return a string, result discarded
I have browsed through the documentation, but I can't find anything. Does anybody know where the failure is?
Several guidances on how to implement functions in Conky:
First of all: YOU MUST USE conky_ BEFORE YOUR FUNCTION'S NAME.
Otherwise, you will get the following error when running your Conky:
attempt to call a nil value
Secondly: YOU MUST ALWAYS RETURN A VALUE.
I don't mind repeating it - it is crucial. Otherwise, you will get:
function foobar didn't return a string, result discarded
function_result
...in your terminal, and your Conky will be left empty of values related to your extra code. Nothing will be printed regarding your function.
Last but not least: YOU MUST ALWAYS CALL YOUR FUNCTION LIKE:
lua_load = '/path/to/function.lua',
-- Whatever content...
${lua function_name function_parameter1 function_parameterN} -- In case you use more than one parameter.
In summary, a dummy function template could be:
MAIN FILE (conky.conf):
conky.config = {
-- Whatever content... Lua styled comments.
lua_load = '/path/to/function.lua',
}
conky.text = [[
# Whatever content... In this section comments are started with '#'!
${lua function_name parameter}
]]
FUNCTION FILE:
function conky_function_name(parameter)
-- Whatever content... Remember this is Lua, not conky.text syntax. Always use '--' comments!
return whatever -- No return, no party. A function MUST always return something!
end

Lua Naming a table from function input

If I do something wrong with the formatting or anything else, sorry, I don't use this site often.
I'm trying to make a function in lua that with take a name I give it, and create a subtable with that name, and when I tried something like this it just made the absolute name I put in the function's code.
NewSubtable =
function(SubtableName)
Table.SubtableName = {} --Creates a subtable called SubtableName
end
How can I make this create a subtable that is called by the name I give in the function when I use it? Is there an indicator or something to let the code know not to use the name given, but to use the variable assigned when I use the function?
EDIT: So whenever I try this, I get the the result "table index is nil" and it points to the error on line 4
I went and tested this but with a different input type, and it was just my fault. I didn't think that strings would the the value type you'd need for what I'm doing. My problem is solved.
Complete code:
Items = {}
NewWeapon = function(id, name, desc, minDMG, maxDMG)
Items[id] = {}
Items[id].Name = name
Items[id].Desc = desc
Items[id].MinDMG = minDMG
Items[id].MaxDMG = maxDMG
end
NewWeapon(Test, "test", "test", 1, 1)
Table.SubtableName is actually a syntactic sugar for Table['SubtableName']. To use the contents of variable SubtableName use the idom Table[SubtableName].

How to use Transactions in cakephp

I write this code, but its not working, it gives this error
Call to a member function commit() on a non-object
Hear is my code
$datasource = $this->Arrear->getDataSource();
$datasource->begin();
if($this->Customar->saveField("total_bake",$amount) && $this->Arrear->save()){
$dataSource->commit();
return $this->redirect(array('action'=>'index'));
}else{
$dataSource->rollback();
$this->Session->setFlash('Data insert Failed','failure');
}
Variables in php(and hence in cakephp as well) are case-sensitive
http://php.net/manual/en/language.variables.basics.php
you have in your first line
$datasource = $this->Arrear->getDataSource();
but you are committing like
$dataSource->commit();
you have the data source assigned to $datasource, but not to $dataSource. The last variable even is not defined, that is why it is showing that error. So, you have to be sure you are using exactly the same variable (with same capitalization) in all places.

Calling the function name

As a beginner in Lua, I am sorry if the answer on this is easy.
I was trying to call a function within a code, yet after 2 hours of searching I couldn't find the wanted results. (Maybe I use the wrong search query's?)
Example code
function Test123 ()
SayTest = True
if SayTest = True then
-- This Is where I want to call the function name Test123,
-- yet I can't seem to succeed in this since it is just
-- starting a new function
SystemNotice ( role, function)
end
end
This should be the result:
function Test123 ()
SayTest = True
if SayTest = True then
SystemNotice ( role, 'Test123')
end
end
If anyone can help me out, I would be thankful. If I am still being unclear, just tell me and I will try to describe it better. My excuses for my limited English.
In Lua functions are actually values. That means they do not really have a name, you can only assign them to a variable or table field, but since the value itself has no concept of its name, you can't retrieve it.
That said, with the debug library, you can do this:
function getfname()
return debug.traceback("", 2):match("in function '(.-)'");
end
function bar()
print(getfname())
end
bar(); -- prints bar
foo = bar;
foo() -- prints foo
knerf = {rab = bar};
knerf.rab() -- prints rab
Note that this only works with the default Lua error handler or one that returns the same or very similar output, however you can obviously modify the pattern to suit what you need.
Read this: I would not advise this solution for performance-intensive tasks. Both string matching and the traceback are not really suited for this. Also, obviously the debug library must be enabled so you can actually use the traceback function.
Your function declaration lacks anend.
function Test123 ()
end
Read the functions chapter from the Lua manual. Just for the record, your if will also need an end.
This is a construct that just goes against the Lua philosophy that functions are first class citizens:
a function is just another value, and as such it has no name.
A variable can be assigned a value, thus binding a function to a name.
But that name can change. or a function can have multiple names. Which one to pick?
A better solution would be creating an anonymous function with an upvalue (a closure) instead:
function genTest(name)
return function()
SayTest = true
if SayTest == true then
print ( 'role', name)
end
end
end
Test123 = genTest('Test123')
Test123()
foobar = Test123
foobar()
This creates a function with a bound local variable name (see PiL 6.1 ).