[sr-dev] trouble with testing $var

[Andrei Pelinescu-Onciul]

On Nov 09, 2009 at 22:58, Juha Heinanen <jh at tutpro.com> wrote:
> Andrei Pelinescu-Onciul writes:
> 
>  > >    $var(tmp) = $(ru{uri.param,alias});
>  > >    xlog("L_INFO", "Alias param is <$var(tmp)>\n");
>  > >    if ($var(tmp)) {
>  > > 	    xlog("L_INFO", "Alias param is <$var(tmp)>\n");
>  > > 	    $du = $var(tmp);
>  >         ^^^^^^^^
>  >         shouldn't it be $du = "sip:" + $var(tmp) ?
> 
> andrei,
> 
> yes, it should have been like that.  now handle_alias() takes care of
> it.
> 
>  > > why does the test
>  > > 
>  > >    if ($var(tmp)) {
>  > > 
>  > > fail to figure out that $var(tmp) has value?
>  > 
>  > You should use if ($var(tmp)!="").
>  > if ($var(tmp)) works only for integers. If $var(tmp) is not integer and
>  > not a string of the form "1234", it will evaluate to 0 in an integer
>  > context. The if() it's an integer context (no boolean context in sr).
> 
> thanks for the explanation.  i have to say though that as a normal
> programmer, i'm not used to such behavior.
> 
> in order to avoid programming mistakes like that, could it be possible
> to produce a error message if such a test is attempted, i.e., test on
> string valued pvar?

We could generate an error message, but only at runtime (because we
don't know the type of $var(tmp) at script compile time).


Andrei