Re: [Module::Build] ask() and you will receive

[Randy W. S. <ml...@th...>]

Ken Williams wrote:
> 
> On Apr 14, 2006, at 4:44 AM, Randy W. Sims wrote:
> 
>> +
>> +=item default   [required]
>> +
>> +This is the default value that will be used if the user presses
>> +E<lt>enterE<gt> or if running an unattended build.
>> +
>> +The value assigned to C<default> may be different from the options
>> +listed in the C<options> argument.
> 
> I think I'm about to blaspheme, but I think sometimes we shouldn't 
> require there to be a default.
> 
> /me ducks
> 
> Sometimes there's simply no way to build & test & install a module 
> without user intervention.  For example, Inline::Java asks you to tell 
> it where the J2SDK installation is, and there's no default.
> 
> If we changed the error message to something appropriate, I think we 
> could handle this case gracefully, both here and in y_n().  Something like:
> 
>   if ( $ENV{PERL_MM_USE_DEFAULT} && !$def ) {
>     die <<EOF;
> ERROR: PERL_MM_USE_DEFAULT is in effect, but there is no default value.  
> Aborting.
> EOF
>   }
> 
> It might be nice to note this fact in the META.yml file, using a flag 
> like 'interactive_install' or something, so that automated testers don't 
> even try to download & build the distro.
> 
> For a distro that really requires interaction like this, the author 
> could work around our proposed required 'default' by setting 'default' 
> to undef and then die()ing with their own error message if prompt() or 
> y_n() or ask() returned undef, but why not provide them with the 
> appropriate sugar?

Here's a rough rough patch to implement something along those lines, I 
think. Rough day, my brains not working well, and somehow this simple 
little input routine has become one of the largest routines in M::B, so 
I'd appreciate feedback. All names, behaviors, and every last byte 
subject to change.

Randy.