NAME

Tie::HashObject - Perl extension for changing object methods into a limited set of allowed hash keys. Returns a tied hash with keyed access to the defined methods. The original object is accessed through a specially named key.

SYNOPSIS

  #.. example ..

  use Tie::HashObject;

  my $some_object = Bla::Bla->new;
  my %tied_hash;
  tie %tied_hash, 'Tie::HashMethods', { object => $some_object, keys => [qw(method1 method2 etc)] };

  #...or...

  $tied = Tie::HashObject->new(
        object => $someobject,
        keys => [qw(method1 method2 etc)],
  );

  #...generally, you will want to inherit from Tie::HashObject and call it's new...

  package TieThisObject;
  use vars qw(Tie::HashObject);

  sub method1 {$_[0]->{method1} = $_[1]}
  sub method2 {$_[0]->{method2} = $_[1]}

  #...then in the main program you would...
  my $outside = TieThisObject->new(keys => [qw(method1 method2)]);
  
  # Now, from the 'main' program, you will only have access to...
  my $outside = TieThis::Object->new;
  $outside->{method1};
  $outside->{method2};

  # Also, calling these keys from outside the object will actually call the related method, so...
  $outside->{method1} = 5;
  # ...will actually call...
  $self->method1(5);
  # ...from inside the TieThis::Object object.

  # try this for fun...
  @{$outside}{method1 method2} = qw(jelly booba);

  # don't try this...
  $outside->{random_key};
  # ...since you didn't declare this as valid it will return an error warning and not store anything.

  # However, within the class, you will have direct access to the full range of the hash...
  $self->{cgi} = CGI->new; 
  # This would work inside TieThis::Object for example.. (as well as any super class)

DESCRIPTION

This method allows you to quickly create protection for an Object by using a tied hash instead of the standard hash ref. Simply, provide a list of allowed keys and a reference to the original object type.

Note: All calls to the set/retrieve keys from the tied hash object will actually call the internal methods of the same name. So consider this for mostly get/set methods or methods that do a small amount of work. This generally isn't a problem since it is bad practice to call/set blessed reference internals directly.

Reason: I like using hashes and wanted to be able to use object data as a hash without violating direct calls to the object internals. I also wanted to be able to access the object methods.

Pros: It will probably make your module much more safe and convenient to use. Cons: This is will slow things down and use more memory.

I hope this module makes it easy enough for others to begin tying up their module references.

Best luck.

Tie::HashObject

METHODS

new() Can be called as a class or object method. Allows for the following parameters:

  keys
    An arrayref of method names which list the accessible method names. 
    Defaults to the keys already available within the object (but don't do that).
    I may update this to allow a hashref where key names are mapped to methods of 
    a different name.

Tie::HashMethods

TIEHASH()

  keys 
    An arrayref of method names which list the accessible method names. 
    Defaults to the keys already available within the object (but don't do that). 
    I may update this to allow a hashref where key names are mapped to methods of 
    a different name.

object()

    sets the internally stored object. Call this first! Or inherit Tie::HashObject 
    and call it's new() method to do this automatically.

AUTHOR

Jeffrey B Anderson jeff@pvrcanada.com

SEE ALSO

perltie(1). Tie::Hash