NAME

Netscape::Bookmarks::AcceptVisitor - a base class to accept Visitor object

SYNOPSIS

Any Netscape bookmarks object can accept a visitor object. Call the visitor() method on the object with the Vistor object as the argument.

$object->visitor( $visitor );

Although all of the classes in Netscape::Bookmarks currently use Netscape::Bookmarks::AcceptVisitor, that may not always be the case if I decide that a particular object needs a different visitor() method. Always can the visitor() method on the object rather than something else (which I do not tell you about so you won't do it).

DESCRIPTION

The Visitor must define a visit() method which accepts the visited object as an argument. The visitor() method returns undef if the visitor object does not have a visit() method. Inside the visit() method you can do whatever you like. The return value of visitor() is the return value of visit.

Example Visitor class

This example shows the bare minimum of a Visitor for Netscape::Bookmarks. This example increments a count for each object it encounters, which you might want to do to measure the granularity of link categorization (i.e. category to bookmark ratio). The new() method does whatever has to be done to create the Visitor object.

package MyVisitor;

use vars qw( %Class_count );

sub new { ... }

sub visit
	{
	my( $self, $object ) = @_;

	my $class = ref $object;

	$Class_count{$class}++
	}

__END__

I use this visitor in as I traverse the Bookmarks tree:

use MyVisitor;

my $visitor = MyVisitor->new();

my $netscape = Netscape::Bookmarks->new( 'bookmarks.html');

# introduce() traverses for us
$netscape->introduce( $visitor );

EXAMPLES

Some examples come with the Netscape::Bookmarks distribution. See examples/Visitor.pm, for instance.

AUTHOR

brian d foy <bdfoy@cpan.org>

COPYRIGHT AND LICENSE

Copyright © 2002-2016, brian d foy <bdfoy@cpan.org>. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

Netscape::Bookmarks