use Perl

• accessors (Score:1)

  by Dom2 (2981) <{dom} {at} {happygiraffe.net}> on 2002.08.15 12:12 (#11800) Homepage Journal

  Hmmm, I've been caught out by using accessors like that before. This is a more general code issue, and it's probably fine for your small code, but what happens if you want to store undef in your accessor?
  
  This is the reason I am leaning more and more towards Class::Accessor and similiar. I note that you'd have to override set() to return $self that way, however.
  
  -Dom

  Reply to This

  • Re:accessors (Score:1)

    by james (1129)

    > Hmmm, I've been caught out by using accessors like
    > that before. This is a more general code issue,
    > and it's probably fine for your small code, but
    > what happens if you want to store undef in your
    > accessor?
    
    Generally I work very hard to make sure I never need to have an undef in any given state :-)
    
    The object in question will always be in one of two states:

    1. Usable - there is a valid LWP::UserAgent object
    2. Unusable - there is no valid LWP::UserAgent object

    Cases can be made for wanting to
  • Re:accessors (Score:2)

    by wickline (135)

    > what happens if you want to store undef
    
    I usually write something like

    sub foo {
        my $self = shift;
        return   @_  ? $self->{foo}=$_[0]  : $self->{foo};
    }

    which gives you the ability to set something to undef but doesn't let you chain method calls. If you wanted to chain method calls, you could instead write it this way

    sub foo {
        my $self = shift;
        if (@_) {
            $self->{foo} = shift;
         
    • Now I'm just being silly... (Score:2)

      by wickline (135)

      Put these two subroutines somewhere

      sub non_chaining_accessor {
          my $name = (caller 1)[3];
          $name = substr $name, rindex($name,':')+1;
          $#_  ? $_[0]->{$name}=$_[1]  : $_[0]->{$name}
      }
      sub chaining_accessor {
          my $name = (caller 1)[3];
          $name = substr $name, rindex($name,':')+1;
          if ($#_) {
              $_[0]->{$name} = $_[1];
              return $_[0];
          } else {