Re: Validate parameters to Lua functions

[Sean Conner <sean@...>]

It was thus said that the Great C++ RTMP Server once stated:
> 
> On Apr 8, 2011, at 12:11 PM, Sean Conner wrote:
> 
> >  Nope.  All you can really do is see if the function exists.  It's up to
> > the function itself to check the paramters it gets.  

> My scenario is the other way around. I let the user define a lua callback
> function. I know the if he defines myHandlerForMyCustomEvent function, I
> should call it from the C++ when MyCustomEvent is triggered. Now, before
> calling it from C/C++, what I would like is to see if, at least, has the
> proper number of arguments (if determining the type is not possible).
> Otherwise, the user is bound to make mistakes. If C/C++ expects
> myHandlerForMyCustomEvent function to have 3 params and the user defines
> that function with only 1 parameter, I would like to warn him/her before
> continuing:
> 
> "Hey, myHandlerForMyCustomEvent function is not defined properly for C/C++
> needs! It will definitely not do the job because you missed 2 params"

  Unless you parse the submitted Lua script you can't obtain that
information.  Short of that, all you can do is trust the user to write a
function that accepts the proper number of arguments.

  -spc