Hello Brothers,

Lately I've really been getting into OO Perl (and OO programming in general) and I'm kindof having a hard time deciding, sometimes, what should go into my "new" method. Should it be a barebones outline of the object? Should it contain useful data per se?

I decided to consult some random cpan modules on my machine. For example, Archive::New:

sub new {
    my $class = shift;
    my $self  = bless(
        {
            'diskNumber'                            => 0,
            'diskNumberWithStartOfCentralDirectory' => 0,
            'numberOfCentralDirectoriesOnThisDisk'  => 0, # shld be # 
+of members
            'numberOfCentralDirectories'            => 0, # shld be # 
+of members
            'centralDirectorySize' => 0,    # must re-compute on write
            'centralDirectoryOffsetWRTStartingDiskNumber' =>
              0,                            # must re-compute
            'writeEOCDOffset'             => 0,
            'writeCentralDirectoryOffset' => 0,
            'zipfileComment'              => '',
            'eocdOffset'                  => 0,
            'fileName'                    => ''
        },
        $class
    );
    $self->{'members'} = [];
    my $fileName = ( ref( $_[0] ) eq 'HASH' ) ? shift->{filename} : sh
+ift;
    if ($fileName) {
        my $status = $self->read($fileName);
        return $status == AZ_OK ? $self : undef;
    }
    return $self;
}
[download]

and that seems pretty reasonable, sets up kindof a basic structure with a few checks to see if an object is possible. Fair enough. But then I see a lot of like what HTML::Parser does:

sub new
{
    my $class = shift;
    my $self = bless {}, $class;
    return $self->init(@_);
}


sub init
{
    my $self = shift;
    $self->_alloc_pstate;

    my %arg = @_;
    my $api_version = delete $arg{api_version} || (@_ ? 3 : 2);
    if ($api_version >= 4) {
        require Carp;
...
[download]

so here we just get a very basic blessing of an empty hashref into the class, and then a sub "init" does some more heavy lifting of actually defining a unique sort of object. But I find myself writing "new" methods much like REST::Google here:

sub new {
        my $class = shift;

        my $args = $class->_get_args(@_);

        croak "attempting to perform request without setting a service
+ URL"
                unless ( defined $class->service );

        my $uri = URI->new( $class->service );
        $uri->query_form( $args );

        unless ( defined $class->http_referer ) {
                carp "attempting to search without setting a valid htt
+p referer header";
                $class->http_referer( DEFAULT_REFERER );
        }

        my $request = HTTP::Request->new( GET => $uri, [ 'Referer', $c
+lass->http_referer ] );

        my $ua = LWP::UserAgent->new();
        $ua->env_proxy;

        my $response = $ua->request( $request );

        croak sprintf qq/HTTP request failed: %s/, $response->status_l
+ine
                unless $response->is_success;

        my $content = $response->content;

        my $json = JSON::Any->new();
        my $self = $json->decode($content);

        return bless $self, $class;
}
sub new {
        my $class = shift;

        my $args = $class->_get_args(@_);

        croak "attempting to perform request without setting a service
+ URL"
                unless ( defined $class->service );

        my $uri = URI->new( $class->service );
        $uri->query_form( $args );

        unless ( defined $class->http_referer ) {
                carp "attempting to search without setting a valid htt
+p referer header";
                $class->http_referer( DEFAULT_REFERER );
        }

        my $request = HTTP::Request->new( GET => $uri, [ 'Referer', $c
+lass->http_referer ] );

        my $ua = LWP::UserAgent->new();
        $ua->env_proxy;

        my $response = $ua->request( $request );

        croak sprintf qq/HTTP request failed: %s/, $response->status_l
+ine
                unless $response->is_success;

        my $content = $response->content;

        my $json = JSON::Any->new();
        my $self = $json->decode($content);

        return bless $self, $class;
}
[download]

I mean, they do all kinds of stuff in there, really kindof clearing the decks for action right off the bat.

So...which way is right? (if any of these are)?

---

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