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NAME

Class::Dot::Type - Base class for type constraints.

VERSION

This document describes Class::Dot version 2.0.0_15

SYNOPSIS

     # You probably want to get this information from your instance's __meta__
     # attriute.
 
     package MyClass;
     use Class::Dot2;
 
     property 'name' => (isa => 'Str', default => 'Mr. Fox Quick Brown');
 
     sub play_with_attribute_meta {
         my ($self) = @_;
 
         my $name_meta = $self->__meta__('name');
 
         # Get the name of the type for attribute name.
         my $type = $name_meta->type;
 
         # Find out what kind of accessor this is. (default: Overridable)
         my $accessor_type = $name_meta->accessor_type;
 
         # Get a subroutine ref to the constraint check for this type.
         my $check_constraint = $name_meta->constraint;
 
         my $current_value = $self->name;
         if (! $check_constraint->($current_value)) {
             croak "Value of name does not pass the constraint check for $type"
         }
 
 
         # Get the getter and setter name.
         my $getter_name   = $name_meta->getter_name;
         my $setter_name   = $name_meta->setter_name;
 
         # get the value by calling name():
         $current_value = $self->$getter_name;
 
         # set the value by calling set_name($value)
         $self->$setter_name('new value');
 
         # Get the list of parents for this type.
         my @isa_for_type = $meta->linear_isa; 
 
         # Get the privacy option for this type (default: public (rw)).
         my $privacy_type = $meta->privacy;
 
         # Get the privacy rules for this privacy type.
         my $privacy_rules = $meta->privacy_rule;
 
         print $privacy_rules->{has_getter};
         print $privacy_rules->{has_setter};
 
         return;
     }

DESCRIPTION

This is the base class for all Class::Dot type constraints.

It ensures easy access to type metadata.

SUBROUTINES/METHODS

CLASS CONSTRUCTOR

new($options_ref)

Create a new type instance.

ATTRIBUTES

type()

Get the name of this attributes type.

accessor_type()

Get the type of accessor this attribute has. Common types include: Overrideable, Chained or Constrained.

See the manual for the given type:

This is the default type. It is easy to override in many ways as long as the -override class/attribute option is set.

This accessor type always returns the instance itself when you set a value. This makes it possible to write code like this:

     my $person = Person->new
                     ->name('George Constanza')
                     ->address('Foo foo foo')
                     ->birthday(19720512);

Is the same as Overrideable except it will check if the values given conforms to the type constraint, if it doesn't it will die with an error.

constraint()

This is a subroutine reference to a function that checks wether a value conforms to the type constraint or not. It will return 1 if the value do, and undef otherwise.

Example:

     my $tyoe_meta        = $self->__meta__($attr);
     my $check_constraint = $type_meta->constraint();
 
     if (not $check_constraint->($value)) {
         croak "The value is not a valid " . $type_meta->type;
     }

getter_name()

The name of the get accessor for this attribute.

setter_name()

The name of the set accessor for this attribute.

linear_isa()

The list of parent types this type inherits from.

privacy()

The attributes privacy setting.

Common privacy types:

  • public (alias: rw)

The public can both read and write from this attribute.

  • readonly (alias: ro)

The public can only read from this attribute.

(You can still read the value with $self->__getattr__($attr_name)).

  • writeonly (alias: wo)

The public can only write to this attribute.

(You can still write to this attribute with ($self->__setattr__($attr_name, $value)).

  • private (alias: xx)

The attribute is private and has no autogenerated accessors. You can still set a value with __setattr__ and __getattr__ (see: Class::Dot::Object).

privacy_rule()

Get the privacy rules for this type instance.

Common rules include:

  • has_getter

Is true if the attribute is public, or readonly (rw or ro), but not true if the attribute is writeonly (wo).

  • has_setter

Is true if the attribute is public or writeonly (rw or wo), but not if the attribute is readonly (ro).

DIAGNOSTICS

This module has no error messages.

CONFIGURATION AND ENVIRONMENT

This module requires no configuration file or environment variables.

DEPENDENCIES

INCOMPATIBILITIES

None known.

BUGS AND LIMITATIONS

No bugs have been reported.

Please report any bugs or feature requests to bug-class-dot@rt.cpan.org, or through the web interface at CPAN Bug tracker.

SEE ALSO

Class::Dot::Manual

Class::Dot

Class::Dot::Typemap

AUTHOR

Ask Solem, asksh@cpan.org.

LICENSE AND COPYRIGHT

Copyright (c), 2007 Ask Solem ask@0x61736b.net.

Class::Dot is distributed under the Modified BSD License.

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

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

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

3. 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.

DISCLAIMER OF WARRANTY

BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENSE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

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