Object::Declare(3)

NAME
Object::Declare - Declarative object constructor

VERSION
version 0.23

SYNOPSIS
    use Object::Declare ['MyApp::Column', 'MyApp::Param'];

    my %objects = declare {

    param foo =>
       !is global,
        is immutable,
        valid_values are qw( more values );

    column bar =>
        field1 is 'value',
        field2 is 'some_other_value',
        sub_params are param( is happy ), param ( is sad );

    };

    print $objects{foo}; # a MyApp::Param object
    print $objects{bar}; # a MyApp::Column object

    # Assuming that MyApp::Column::new simply blesses into a hash...
    print $objects{bar}{sub_params}[0]; # a MyApp::Param object
    print $objects{bar}{sub_params}[1]; # a MyApp::Param object

DESCRIPTION
This module exports one function, "declare", for building named objects with a declarative syntax, similar to how Jifty::DBI::Schema defines its columns.

In list context, "declare" returns a list of name/object pairs in the order of declaration (allowing duplicates), suitable for putting into a hash. In scalar context, "declare" returns a hash reference.

Using a flexible "import" interface, one can change exported helper functions names (declarator), words to link labels and values together (copula), and the table of named classes to declare (mapping):

    use Object::Declare
        declarator  => ['declare'],     # list of declarators
        copula      => {                # list of words, or a map
            is  => '',                  #  from copula to label prefixes,
            are => '',                  #  or to callback that e.g. turns
            has => sub { has => @_ },   #  "has X" to "has is X" and
                                        #  "X has 1" to "has is [X => 1]"
        },
        aliases     => {                # list of label aliases:
            more => 'less',             #  turns "is more" into "is less"
                                        #  and "more is 1" into "less is 1"
        },
        mapping     => {
            column => 'MyApp::Column',  # class name to call ->new to
            param  => sub {             # arbitrary coderef also works
                bless(\@_, 'MyApp::Param');
            },
        };

After the declarator block finishes execution, all helper functions are removed from the package. Same-named functions (such as &is and &are) that existed before the declarator's execution are restored correctly.

NOTES
If you export the declarator to another package via @EXPORT, be sure to export all mapping keys as well. For example, this will work for the example above:

    our @EXPORT = qw( declare column param );

But this will not:

    our @EXPORT = qw( declare );

The copula are not turned into functions, so there is no need to export them.

AUTHORS
Audrey Tang <cpan@audreyt.org>

COPYRIGHT
Copyright 2006, 2007 by Audrey Tang <cpan@audreyt.org>.

This software is released under the MIT license cited below.

  The "MIT" License
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

AUTHOR
Shlomi Fish <shlomif@cpan.org>

COPYRIGHT AND LICENSE
This software is Copyright (c) 2006 by Audrey Tang.

This is free software, licensed under:

  The MIT (X11) License

BUGS
Please report any bugs or feature requests on the bugtracker website http://rt.cpan.org/NoAuth/Bugs.html?Dist=Object-Declare or by email to bug-object-declare@rt.cpan.org.

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

SUPPORT

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

  perldoc Object::Declare

  Websites
The following websites have more information about this module, and may be of help to you. As always, in addition to those websites please use your favorite search engine to discover more resources.

•   MetaCPAN

    A modern, open-source CPAN search engine, useful to view POD in HTML format.

    <http://metacpan.org/release/Object-Declare>

•   Search CPAN

    The default CPAN search engine, useful to view POD in HTML format.

    <http://search.cpan.org/dist/Object-Declare>

•   RT: CPAN's Bug Tracker

    The RT ( Request Tracker ) website is the default bug/issue tracking system for CPAN.

    <https://rt.cpan.org/Public/Dist/Display.html?Name=Object-Declare>

•   AnnoCPAN

    The AnnoCPAN is a website that allows community annotations of Perl module documentation.

    <http://annocpan.org/dist/Object-Declare>

•   CPAN Ratings

    The CPAN Ratings is a website that allows community ratings and reviews of Perl modules.

    <http://cpanratings.perl.org/d/Object-Declare>

•   CPAN Forum

    The CPAN Forum is a web forum for discussing Perl modules.

    <http://cpanforum.com/dist/Object-Declare>

•   CPANTS

    The CPANTS is a website that analyzes the Kwalitee ( code metrics ) of a distribution.

    <http://cpants.cpanauthors.org/dist/Object-Declare>

•   CPAN Testers

    The CPAN Testers is a network of smokers who run automated tests on uploaded CPAN distributions.

    <http://www.cpantesters.org/distro/O/Object-Declare>

•   CPAN Testers Matrix

    The CPAN Testers Matrix is a website that provides a visual overview of the test results for a distribution on various Perls/platforms.

    <http://matrix.cpantesters.org/?dist=Object-Declare>

•   CPAN Testers Dependencies

    The CPAN Testers Dependencies is a website that shows a chart of the test results of all dependencies for a distribution.

    <http://deps.cpantesters.org/?module=Object::Declare>

  Bugs / Feature Requests
Please report any bugs or feature requests by email to "bug-object-declare at rt.cpan.org", or through the web interface at <https://rt.cpan.org/Public/Bug/Report.html?Queue=Object-Declare>. You will be automatically notified of any progress on the request by the system.

  Source Code
The code is open to the world, and available for you to hack on. Please feel free to browse it and play with it, or whatever. If you want to contribute patches, please send me a diff or prod me to pull from your repository :)

<https://github.com/shlomif/perl-Object-Declare>

  git clone git://github.com/shlomif/perl-Object-Declare.git