/ 
hub-standard-04.00.043
/ Hub::Knots::TiedObject

NAME

Hub::Knots::TiedObject - Tied object

SYNOPSIS

In your class:

package __Package_Name__;
use Hub qw(:lib);
sub new {
  my $self = shift;
  my $class = ref( $self ) || $self;
  my $obj = bless {}, $class;
  tie %$obj, 'Hub::Knots::TiedObject', '__Tie_Package__';
  return $obj;
}#new

DESCRIPTION

Perl5 does not let one implement tie methods for a normal blessed package. To get around this, the above constructor ties the blessed reference to this package, providing '__Tie_Package__' as the package which should implement the tie methods.

Intention

To transparently provide `tie' methods inline with an existing class. For example, one may have a User class which supports several methods, such as `print', and we wish to update the database on the fly...

my $user = new User( $conn, 'mary', 'alzxjVT8kR.aU' );
$user->{'lname'} = "Lopez";
$user->print();

Implementation

TiedObject simply provides two hashes for the object: `public' and `private'. When data members are accessed, the 'public' hash is acted upon. If the index begins with an asterisk (*) then the private hash is used. The only values currently in the private hash are:

$self->{'*tied'};         # Points to the reference returned by tie-ing 
                          # '__Tie_Package__' to the public hash.

$self->{'*public'};       # Points to the public hash

INTERNAL METHODS

_key

Determine which key (public or private) to use

TIEHASH

Tie interface method
Usage: TIEHASH 'Hub::Knots::TiedObject', $PACKAGE

FETCH

Return a value

STORE

Store a value

DELETE

Remove a value

CLEAR

Remove all public values

EXISTS

Boolean test for value

FIRSTKEY

Tie interface method

NEXTKEY

Tie interface method

SCALAR

Scalar representation

UNTIE

Tie interface method

AUTHOR

Ryan Gies (ryangies@livesite.net)

COPYRIGHT

Copyright (C) 2006-2007 by Livesite Networks, LLC. All rights reserved.

Copyright (C) 2000-2005 by Ryan Gies. All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

* The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.

* Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.

* The name of the author may not be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

To the best of our knowledge, no patented algorithms have been used. However, we do not have the resources to carry out a patent search, and therefore cannot give any guarantee of the above statement.

UPDATED

08/02/2007