From: darren kirby <bulliver@...>
Date: 2006-06-07T05:25:04+09:00
Subject: Attributes not populated until called?

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Hello all,

Pretty much new to Ruby, and I think I am not grasping something fundamenta=
l=20
here. I've written some classes that grab meta tags from various audio file=
=20
formats, and overrode 'to_s" to dump the tags to the console, and "to_a" to=
=20
dump the tags to an array for use elsewhere in my program.

I am not sure how to explain my problem, so I will just paste in a session=
=20
from irb that shows it:

irb> require 'sneetchalizer'  # my class definitions...
irb> x =3DOggMetaTags.new('/home/music/e/elliottSmith-shootingStar.ogg')
=3D> #<OggMetaTags:0xa7cc1ac8 [...rest omitted...]
irb> x.to_a
=3D> ["", "", "", "", "", "", ""]
irb> x.title
=3D> "Shooting Star"
irb> x.to_a
=3D> ["Shooting Star", "", "", "", "", "", ""]
irb> x.artist
=3D> "Elliott Smith"
irb> x.to_a
=3D> ["Shooting Star", "Elliott Smith", "", "", "", "", ""]

So you can see I need to explicitly call each attribute before my array get=
s=20
the value. How can I change this so the array is populated automatically wh=
en=20
called?

Here is the class:

class OggMetaTags < MetaTags
  def initialize(filename)
    @filename =3D filename
    require 'ogginfo'
    @tags =3D OggInfo.new(@filename)
  end
  def title
    @title =3D @tags.tag['title']
  end
  def artist
    @artist =3D @tags.tag['artist']
  end
  def album
    @album =3D @tags.tag['album']
  end
  def genre
    @genre =3D @tags.tag['genre']
  end
  def year
    @year =3D @tags.tag['date']
  end
  def comment
    @comment =3D super
  end
  def tracknum
    @tracknum =3D @tags.tag['tracknumber']
  end

  def to_a
    ["#@title", "#@artist", "#@album", "#@genre", "#@year", "#@comment",=20
"#@tracknum"]
  end
end

If you need more info or want to see all the code please just ask. Thanks f=
or=20
consideration,
=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

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