Problem initializing an object as an instant variable

lightbringer has asked for the wisdom of the Perl Monks concerning the following question:

Hi, I'm trying to create an object instant variable inside the constructor of another class, but the instant variable is not recognized after initialized. Could anyone help me on this one, please.

use Net::Telnet();
package L_Switch;

sub new {
    my $class = shift;
    my $location = shift;
    my $ip = shift;
    my $self = {};
    $self -> {'ip'} = $ip;
    $self -> {'location'} = $location;
    $self -> {'full_info'} = "asd";
    $self -> {'fault'} = "";
    $self -> {'time_out'} = "";
    $self -> {'telnetConn'} => new Net::Telnet(
            Timeout => 10,
            errmode =>                     # if connection is unsucces
+sful
            (
                sub {
                    $self -> {'full_info'} = CLIENT . ",," . $ip . ",T
+IMEOUT";
                    $self -> {'fault'} = "-No Response";
                    $self -> {'time_out'} = 1;
                }
            )
        );
    bless $self, $class;
    return $self;
}

sub login {
    my $self = shift;
    $self -> {'telnetConn'} -> open($self -> {ip});
    $self -> {'telnetConn'} -> login(USERNAME, PASSWORD);
}

1;
[download]

telnetConn is the instant variable that has problems. I tried to use it in Login method, but the error returned is

Can't call method "open" on an undefined value at L_Switch.pm.

Comment on Problem initializing an object as an instant variable Download Code

Replies are listed 'Best First'.
Re: Problem initializing an object as an instant variable by McA (Priest) on Jun 27, 2012 at 02:31 UTC
Hi, IMHO it's a simple typo. Look at: `$self -> {'telnetConn'} => new Net::Telnet( Timeout => 10, errmode => # if connection is unsuccessful ( sub { $self -> {'full_info'} = CLIENT . ",," . $ip . ",TIMEO +UT"; $self -> {'fault'} = "-No Response"; $self -> {'time_out'} = 1; } ) );` [download] You don't have an assignment. You used '=>'. Please get used to the more correct object instantitation idiom `Net::Telnet->new`. There are articles out there explaining the subtle differences and pitfalls. Best regards McA	[reply] [d/l] [select]
Re: Problem initializing an object as an instant variable by muba (Priest) on Jun 27, 2012 at 02:21 UTC
Do you get any other error messages? What do they tell you? Do you `use strict;` and `use warnings;`? Are their complaints in any way helpful? What is `CLIENT` in `$self -> {'full_info'} = CLIENT . ",," . $ip . ",TIMEOUT";`? Does the Net::Telnet constructor take `errmode` as an argument? The documentation says `Errmode` (mind the capital initial). How flexible is the module about that sort of things? Were there no error messages complaining about this? Have you tried to rewrite it as `$self -> {'telnetConn'} => Net::Telnet->new(...);`?	[reply] [d/l] [select]