Hi Monks , I Had a task like below.

The task is to put together a little web robot, using our module Webrobot.pm, login to a Facebook account and using the regex commands in the Webrobot, get the number of friends the Facebook user has and print it out to the screen.

I worked with Basic Perl.

Can you tell me What could be the difficulties involved in it? is it related to CGI and Webrelated Programming using Perl for the above task

Please find the Webrobot.pm here

package Webrobot;
 
use strict;
use warnings;

use English;
use XML::Parser;
use XML::SimpleObject;
use LWP::UserAgent;
use HTTP::Cookies;
use HTTP::Request::Common;
use Storable;
use DateTime;

use base qw(
    Webrobot::Base
    Webrobot::Command::Auto
    Webrobot::Command::Exec
    Webrobot::Command::Match
    Webrobot::Command::Set
    Webrobot::Command::Form
    Webrobot::Command::Input
    Webrobot::Command::Filter
    Webrobot::Command::Method
    Webrobot::Command::Default
    Webrobot::Command::HTML
    Webrobot::Command::Push
    Webrobot::Command::Foreach
);

use constant DEBUG => 1;

sub new {
    my $class = shift;
    my $self = {};
    %$self = @_;
    my $script = $self->{script};
    $self->{keep_alive} = 1 unless defined $self->{keep_alive};
    die "No script specified" unless defined $script;
    $self->{xmlfile} = $script . '.xml';
    die "$self->{xmlfile} is not a plain file" unless -f $self->{xmlfi
+le};
    DEBUG && print "Webrobot keep_alive : $self->{keep_alive}\n";
    $self->{ua} = LWP::UserAgent->new(
        agent => 'Mozilla/5.0 (Macintosh; U; Intel Mac OS X; sv-SE; rv
+:1.8.1.9) Gecko/20071025 Firefox/2.0.0.9',
        keep_alive => $self->{keep_alive}
    );

    if( $self->{debug} ) {
        $self->{ua}->default_header('Accept-Encoding' => scalar HTTP::
+Message::decodable());
        $self->{ua}->add_handler("request_send",  sub { shift->dump; r
+eturn });
        $self->{ua}->add_handler("response_done", sub { shift->dump; r
+eturn });
    }

    my $jarfile = 'var/gluepay/webrobot.jar';
    $self->{jarfile} = $jarfile;
    unlink($jarfile) unless defined($self->{persistent}) && $self->{pe
+rsistent} == 1;
    $self->{jar} = HTTP::Cookies->new(
        file       => $jarfile,
        ignore_discard => 1,
        autosave       => 1
    );
    $self->{ua}->cookie_jar($self->{jar});

    my $stashfile = 'var/gluepay/webrobot.stash';
    if( -f $stashfile && $self->{persistent} ) {
        open FP, '<' . $stashfile;
         my $bin = do { local $/; <FP> };
        close FP;
        ($self->{stash}) = Storable::thaw($bin);
    }

    bless($self,$class);
    return $self;
}
sub store_stash {
    my $self = shift;
    open FP, '>var/gluepay/webrobot.stash';
    print FP Storable::freeze($self->{stash});
    close FP;
}
sub flushcookies {
    my $self = shift;
    $self->{stash} = {};
    undef($self->{referer});
    $self->{ua} = LWP::UserAgent->new(
        agent => 'Mozilla/5.0 (Macintosh; U; Intel Mac OS X; sv-SE; rv
+:1.8.1.9) Gecko/20071025 Firefox/2.0.0.9',
        keep_alive => $self->{keep_alive}
    );
    if( $self->{debug} ) {
        $self->{ua}->default_header('Accept-Encoding' => scalar HTTP::
+Message::decodable());
        $self->{ua}->add_handler("request_send",  sub { shift->dump; r
+eturn });
        $self->{ua}->add_handler("response_done", sub { shift->dump; r
+eturn });
    }
    my $jarfile = $self->{jarfile};
    unlink($jarfile);
    $self->{jar} = HTTP::Cookies->new(
        file       => $jarfile,
        ignore_discard => 1,
        autosave       => 1
    );
    $self->{ua}->cookie_jar($self->{jar});
    return 1;
}
sub run {
    my $self = shift;
    my $xml = $self->_readfile($self->{xmlfile});
    my $parser = XML::Parser->new( ErrorContext => 2, Style => 'Tree' 
+);
    my $script;
    eval { $script = XML::SimpleObject->new( $parser->parse($xml) )->c
+hild('webrobot'); };
    die "Invalid XML file ($EVAL_ERROR)" if( $EVAL_ERROR );
    eval {
        $self->_process($script);
    };
    if( $EVAL_ERROR ) {
        DEBUG && print "FAILED : $EVAL_ERROR\n";
        return undef;
    }
    return $self;
}

sub new_session {
    my $self = shift;
    my $id   = shift;
    $self->{filecounter} = 0;
    $self->{session_id} = $id;
    my $date = DateTime->now()->ymd;
    my $dir = "var/gluepay/webrobot/$date/$id/";
    `mkdir -p $dir`;
    $self->{session_dir} = $dir;
}

sub end_session {
    my $self = shift;
    $self->{filecounter} = 0;
    undef($self->{session_id});
    undef($self->{session_dir});
}

sub _readfile {
    my $self = shift;
    my $filename = shift;
    return undef unless defined $filename;
    open FP, "<$filename";
    my $data = do { local $INPUT_RECORD_SEPARATOR; <FP> };
    close FP;
    return $data;
}

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