package XHR; # Analog zu JavaScript XHR

use strict;
use warnings;
use HTTP::Request;
use LWP::UserAgent;

sub new{
    my $class = shift;
    my $callback = shift;
    bless { ua => LWP::UserAgent->new(), cb => $callback }, $class;
}
sub request{
    my $self = shift;
    my %par = (
        method  => 'GET',
        uri     => '',
        content => '',
        header  => [],
        @_    
    );
    my $r = HTTP::Request->new( @par{qw(method uri header content)} );
    my $res = $self->{ua}->request($r);
    $self->{cb}->($res);
}
###########################################################################
package main;

use strict;
use warnings;

sub callback{
    my $self = shift; # Response Objekt
    print $self->as_string;
}

my $xhr = new XHR(*callback);
$xhr->request(
    uri => 'https://www.rationalgalerie.de/',
);