I'm curious about a technique I've been using for a few months (successfully), which nonetheless seems as if it might not be quite kosher. Basically, in the middle of a constructor, I leave it to run a different program, never to return. This is regular and expected behavior, not an exception.

A simplified version of what I'm trying to do looks more or less like this: 

sub new {
  my ($class, %arg) = @_;
  my $self = { table => $arg{table} || 'test',
           message => $arg{message},
           dbh => MyDatabase::DBManager::connect(),
           cookie_name => $cookie_name,
           # other similar stuff here
         };
  _login_user($self);
  return bless $self, $class;
}

sub _login_user {
  my $self = shift;

  # do something to log the user in based on $self->{cookie_name},
  # returning $sess_ref as a reference to a db-stored session; then:

  if (!defined($sess_ref)) {
    print CGI::redirect(-uri=>'login.cgi');
  }
  # i.e. if there's no session, bounce the user straight to a
  # login page, thus leaving in the middle of the constructor,
  # before hitting the "bless"
  else { # $sess_ref is defined, store some session info into
    # $self and get on with life, returning to "new" and to the
    # original program that called this module
  }
}

[download]

It's been working fine, but I wonder if there's something wrong with doing this as a regular procedure; yet I didn't find anything specifically about it in Camel, Conway, the perltoot & related docs I checked, etc.

So is this safe, or not? If not, what's a good solution, given that the whole point of modularizing this login process is to keep identical code all together?

In reply to OO: Leaving a constructor midway? by jest

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