Class::Tiny::ConstrainedAccessor - Generate Class::Tiny accessors that apply type constraints

Class::Tiny uses custom accessors if they are defined before the use Class::Tiny statement in a package. This module creates custom accessors that behave as standard Class::Tiny accessors except that they apply type constraints (isa relationships). Type constraints can come from Type::Tiny, MooseX::Types, MooX::Types::MooseLike, MouseX::Types, or Specio.

Example of a class using this package:

package SampleClass;
use Scalar::Util qw(looks_like_number);

use Type::Tiny;

my $MediumInteger;
BEGIN {
    # Create the type constraint
    $MediumInteger = Type::Tiny->new(
        name => 'MediumInteger',
        constraint => sub { looks_like_number($_) and $_ >= 10 and $_ < 20 }
    );
}

use Class::Tiny::ConstrainedAccessor {
    medint => $MediumInteger,           # create accessor sub medint()
    med_with_default => $MediumInteger,
};

# After using ConstrainedAccessor, actually define the class attributes.
use Class::Tiny qw(medint regular), {
    med_with_default => 12,
};

SUBROUTINES

import

Creates the accessors you have requested. Basic usage:

use Class::Tiny::ConstrainedAccessor
    name => constraint
    [, name => constraint ...]; # ... any number of name=>constraint pairs

This also creates a BUILD() subroutine to check the constructor parameters, if a BUILD() doesn't already exist.

If a BUILD() does exist (e.g., you said use subs 'BUILD';), this package will create the same function, taking the same parameters as BUILD() would, but call it _check_all_constraints(). You can call this checker from your own BUILD() if you want to.

OPTIONS

To specify options, pass an arrayref as the first argument on the `use` line. This is to leave room for someday carrying attributes and constraints in a hashref. For example:

use Class::Tiny::ConstrainedAccessor [ OPTION=>value ],
    name => constraint ...;

Valid options are:

• NOBUILD

  If NOBUILD => 1 is given, the constructor-parameter-checker is created as _check_all_constraints regardless of whether BUILD() exists or not. Example:

    package MyClass;
    use Class::Tiny::ConstrainedAccessor
        [NOBUILD => 1],
        foo => SomeConstraint;
    # Now $object->_check_all_constraints($args) exists, but not BUILD().
  

AUTHORS

Created by Christopher White, <cxwembedded at gmail.com>. Thanks to Toby Inkster for code contributions.

BUGS

Please report any bugs or feature requests through the GitHub Issues interface at https://github.com/cxw42/Class-Tiny-ConstrainedAccessor/issues. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

perldoc Class::Tiny::ConstrainedAccessor

You can also look for information at:

• GitHub (report bugs here)

  https://github.com/cxw42/Class-Tiny-ConstrainedAccessor

• Search CPAN

  https://metacpan.org/release/Class-Tiny-ConstrainedAccessor

LICENSE

Copyright 2019 Christopher White.

This program is free software; you can redistribute it and/or modify it under the terms of the the Apache License (2.0). You may obtain a copy of the full license at:

https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.