From: darren kirby <bulliver@...>
Date: 2006-06-11T04:53:50+09:00
Subject: Re: Global not evaluated properly in 'if' statement modifier

--nextPart1865943.BM6gAlK0ee
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline

quoth the Esteban Manchado Vel=E1zquez:
> Hi Darren,

Hi,=20
I did get it sorted but I wanted to respond to your comments...

<snip>
>
>     Some suggestions:
>
>     1) I would calculate the method name dinamically with $outtype, inste=
ad
> of having 4 if constructions. Something like:
>
>     song.send "wavTo#{$outtype.capitalize}"

Hey, that's pretty neat. I wondered if there was a way to run the method ba=
sed=20
on "variable variables". This is certainly more elegant.

>     2) I wouldn't use a global variable anyway. I think it's better sendi=
ng
> the out type as a parameter.

I have tried this. I guess I don't fully understand Ruby namespaces, but=20
$outtype gets it's value from a command line option, and if I don't assign =
it=20
to a global then I get:
undefined local variable or method `outtype' for main:Object (NameError)

It is assigned thusly:

opts.each do |opt, arg|
  $outtype =3D arg if ( opt =3D=3D '--out' )
[etc...]
end

If I assign to a regular variable 'outtype' and then pass it to=20
dispatchFile():

files.each { |file| dispatchFile(file, outtype) }

I get the undefined variable error, so I guess vars in the do loop are=20
private, and I don't know how to use them outside of the loop if they are n=
ot=20
globals.

>     3) What is "type", a method? It should probably also be a parameter f=
or
> dispatchFile, but I don't know if that's a function or a method.

'type' is a simple variable that holds the type of infile. So if the infile=
 is=20
an ogg, type will be 'ogg'. It's value is actually assigned in dispatchFile=
=20
(the method I posted), I just removed a few housekeeping lines to keep the=
=20
code I posted short.=20

>     4) Wouldn't it be better having dispatchFile as a Convert method?
> Perhaps with other name, but...

I don't know if this is feasible. It would certainly be a lot of rewriting =
to=20
do it. Convert only accepts 1 file at a time. The way my script works is to=
=20
create an array of files from the command line arguments, then feed one by=
=20
one to dispatchFile, where the proper Convert methods will be run depending=
=20
on the input and output formats. This allows me to just send any file to=20
Convert and it will Do The Right Thing.

>
>     I made a quick test and it worked for me, but I don't know the rest of
> your code. This is the example that worked:
>
> ------------------------------------- 8<
> ------------------------------------- class Convert
>     def initialize(file); end
>
>     def oggToWav;  puts "oggToWav"; end
>     def wavToOgg;  puts "wavToOgg"; end
>     def wavToMp3;  puts "wavToMp3"; end
>     def wavToM4b;  puts "wavToM4b"; end
>     def wavToFlac; puts "wavToFlac"; end
> end
>
> def type; "ogg"; end
>
> $outtype =3D 'mp3'
>
> def dispatchFile(file)
>   song =3D Convert.new(file)
>   case type
>   when 'ogg'
>     song.oggToWav
>     song.wavToOgg  if $outtype =3D=3D 'ogg'
>     song.wavToMp3  if $outtype =3D=3D 'mp3'
>     song.wavToM4b  if $outtype =3D=3D 'm4b'
>     song.wavToFlac if $outtype =3D=3D 'flac'
>   when 'mp3'
>     puts "mp3 nsbb"
>   end
> end
>
>
> dispatchFile('foo')
> ------------------------------------- >8
> -------------------------------------
>
> It printed "oggToWav" and "wavToMp3".  It probably has nothing to do with
> global variables not evaluating, but I can't tell without seeing the rest
> of the code.
>
>     Regards,

Thanks a lot for your help,
=2Dd
=2D-=20
darren kirby :: Part of the problem since 1976 :: http://badcomputer.org
"...the number of UNIX installations has grown to 10, with more expected..."
=2D Dennis Ritchie and Ken Thompson, June 1972

--nextPart1865943.BM6gAlK0ee
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.3 (GNU/Linux)

iD8DBQBEiyMswPD5Cr/3CJgRAplGAJ4lPQYjNnGEpUgPmf419Ji1szgflQCeNbsR
o+vkb2l2t6rG/kzYrHovMDM=
=BkW7
-----END PGP SIGNATURE-----

--nextPart1865943.BM6gAlK0ee--