in reply to Re: Tie::SecureHash and AUTOLOAD'ing
in thread Tie::SecureHash and AUTOLOAD'ing

arh yes, but I can also do this 
package main;

my $id = DogTag->new(name=>"Smith",rank=>"private",serial=>'1234567');

print $id->name();

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which somewhat defeats the purpose of Tie::SecureHash. What I really need is an autoloader that correctly enforces the same rules as Tie::SecureHash

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Re: Re: Re: Tie::SecureHash and AUTOLOAD'ing
by TheDamian (Vicar) on Apr 11, 2003 at 22:52 UTC
    Okay, but first notice that the AUTOLOAD is enforcing encapsulation. You can call attribute accessors, but only ever to retrieve the current values, not to set new ones.

    Remember: encapsulation is not about preventing access to attributes; it's about controlling access to attributes.

    If you want the control that the AUTOLOAD enforces to be identical to the control that Tie::SecureHash enforces (which is a perfectly reasonable thing to want), just code AUTOLOAD accordingly: 

    sub AUTOLOAD {
    my ($self, $newval) = @_;
    $AUTOLOAD =~ s/.*:://;
    my $attr;
    if (exists $self->{$attr=$AUTOLOAD}) {
        # public attribute always accessible
    }
    elsif (exists $self->{$attr="_$AUTOLOAD"}) {
        croak "Cannot access protected attribute '$attr'"
            unless caller().isa(ref $self);
    }
    elsif (exists $self->{$attr="__$AUTOLOAD"}) {
        croak "Cannot access private attribute '$attr'"
            unless caller() eq ref $self;
    }
    else {
        croak "No such attribute ($AUTOLOAD) for object"
    }
    $self->{$attr} = $newval if @_ > 1;
    return $self->{$attr};
}

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