plucky (3) Class::Accessor::Grouped.3pm.gz

Provided by: libclass-accessor-grouped-perl_0.10014-2_all bug

NAME

       Class::Accessor::Grouped - Lets you build groups of accessors

SYNOPSIS

        use base 'Class::Accessor::Grouped';

        # make basic accessors for objects
        __PACKAGE__->mk_group_accessors(simple => qw(id name email));

        # make accessor that works for objects and classes
        __PACKAGE__->mk_group_accessors(inherited => 'awesome_level');

        # make an accessor which calls a custom pair of getters/setters
        sub get_column { ... this will be called when you do $obj->name() ... }
        sub set_column { ... this will be called when you do $obj->name('foo') ... }
        __PACKAGE__->mk_group_accessors(column => 'name');

DESCRIPTION

       This class lets you build groups of accessors that will call different getters and setters. The
       documentation of this module still requires a lot of work (volunteers welcome >.>), but in the meantime
       you can refer to this post <http://lo-f.at/glahn/2009/08/WritingPowerfulAccessorsForPerlClasses.html> for
       more information.

   Notes on accessor names
       In general method names in Perl are considered identifiers, and as such need to conform to the identifier
       specification of "qr/\A[A-Z_a-z][0-9A-Z_a-z]*\z/".  While it is rather easy to invoke methods with non-
       standard names ("$obj->${\"anything goes"}"), it is not possible to properly declare such methods without
       the use of Sub::Name. Since this module must be able to function identically with and without its
       optional dependencies, starting with version 0.10008 attempting to declare an accessor with a non-
       standard name is a fatal error (such operations would silently succeed since version 0.08004, as long as
       Sub::Name is present, or otherwise would result in a syntax error during a string eval).

       Unfortunately in the years since 0.08004 a rather large body of code accumulated in the wild that does
       attempt to declare accessors with funny names. One notable perpetrator is DBIx::Class::Schema::Loader,
       which under certain conditions could create accessors of the "column" group which start with numbers
       and/or some other punctuation (the proper way would be to declare columns with the "accessor" attribute
       set to "undef").

       Therefore an escape mechanism is provided via the environment variable "CAG_ILLEGAL_ACCESSOR_NAME_OK".
       When set to a true value, one warning is issued per class on attempts to declare an accessor with a non-
       conforming name, and as long as Sub::Name is available all accessors will be properly created. Regardless
       of this setting, accessor names containing nulls "\0" are disallowed, due to various deficiencies in perl
       itself.

       If your code base has too many instances of illegal accessor declarations, and a fix is not feasible due
       to time constraints, it is possible to disable the warnings altogether by setting
       $ENV{CAG_ILLEGAL_ACCESSOR_NAME_OK} to "DO_NOT_WARN" (observe capitalization).

METHODS

   mk_group_accessors
        __PACKAGE__->mk_group_accessors(simple => 'hair_length', [ hair_color => 'hc' ]);

       Arguments: $group, @fieldspec
           Returns: none

       Creates a set of accessors in a given group.

       $group is the name of the accessor group for the generated accessors; they will call get_$group($field)
       on get and set_$group($field, $value) on set.

       If you want to mimic Class::Accessor's mk_accessors $group has to be 'simple' to tell
       Class::Accessor::Grouped to use its own get_simple and set_simple methods.

       @fieldspec is a list of field/accessor names; if a fieldspec is a scalar this is used as both field and
       accessor name, if a listref it is expected to be of the form [ $accessor, $field ].

   mk_group_ro_accessors
        __PACKAGE__->mk_group_ro_accessors(simple => 'birthdate', [ social_security_number => 'ssn' ]);

       Arguments: $group, @fieldspec
           Returns: none

       Creates a set of read only accessors in a given group. Identical to "mk_group_accessors" but accessors
       will throw an error if passed a value rather than setting the value.

   mk_group_wo_accessors
        __PACKAGE__->mk_group_wo_accessors(simple => 'lie', [ subject => 'subj' ]);

       Arguments: $group, @fieldspec
           Returns: none

       Creates a set of write only accessors in a given group. Identical to "mk_group_accessors" but accessors
       will throw an error if not passed a value rather than getting the value.

   get_simple
       Arguments: $field
           Returns: $value

       Simple getter for hash-based objects which returns the value for the field name passed as an argument.

   set_simple
       Arguments: $field, $new_value
           Returns: $new_value

       Simple setter for hash-based objects which sets and then returns the value for the field name passed as
       an argument.

   get_inherited
       Arguments: $field
           Returns: $value

       Simple getter for Classes and hash-based objects which returns the value for the field name passed as an
       argument. This behaves much like Class::Data::Accessor where the field can be set in a base class,
       inherited and changed in subclasses, and inherited and changed for object instances.

   set_inherited
       Arguments: $field, $new_value
           Returns: $new_value

       Simple setter for Classes and hash-based objects which sets and then returns the value for the field name
       passed as an argument. When called on a hash-based object it will set the appropriate hash key value.
       When called on a class, it will set a class level variable.

       Note:: This method will die if you try to set an object variable on a non hash-based object.

   get_component_class
       Arguments: $field
           Returns: $value

       Gets the value of the specified component class.

        __PACKAGE__->mk_group_accessors('component_class' => 'result_class');

        $self->result_class->method();

        ## same as
        $self->get_component_class('result_class')->method();

   set_component_class
       Arguments: $field, $class
           Returns: $new_value

       Inherited accessor that automatically loads the specified class before setting it. This method will die
       if the specified class could not be loaded.

        __PACKAGE__->mk_group_accessors('component_class' => 'result_class');
        __PACKAGE__->result_class('MyClass');

        $self->result_class->method();

INTERNAL METHODS

       These methods are documented for clarity, but are never meant to be called directly, and are not really
       meant for overriding either.

   get_super_paths
       Returns a list of 'parent' or 'super' class names that the current class inherited from. This is what
       drives the traversal done by "get_inherited".

   make_group_accessor
        __PACKAGE__->make_group_accessor('simple', 'hair_length', 'hair_length');
        __PACKAGE__->make_group_accessor('simple', 'hc', 'hair_color');

       Arguments: $group, $field, $accessor
           Returns: \&accessor_coderef ?

       Called by mk_group_accessors for each entry in @fieldspec. Either returns a coderef which will be
       installed at "&__PACKAGE__::$accessor", or returns "undef" if it elects to install the coderef on its
       own.

   make_group_ro_accessor
        __PACKAGE__->make_group_ro_accessor('simple', 'birthdate', 'birthdate');
        __PACKAGE__->make_group_ro_accessor('simple', 'ssn', 'social_security_number');

       Arguments: $group, $field, $accessor
           Returns: \&accessor_coderef ?

       Called by mk_group_ro_accessors for each entry in @fieldspec. Either returns a coderef which will be
       installed at "&__PACKAGE__::$accessor", or returns "undef" if it elects to install the coderef on its
       own.

   make_group_wo_accessor
        __PACKAGE__->make_group_wo_accessor('simple', 'lie', 'lie');
        __PACKAGE__->make_group_wo_accessor('simple', 'subj', 'subject');

       Arguments: $group, $field, $accessor
           Returns: \&accessor_coderef ?

       Called by mk_group_wo_accessors for each entry in @fieldspec. Either returns a coderef which will be
       installed at "&__PACKAGE__::$accessor", or returns "undef" if it elects to install the coderef on its
       own.

PERFORMANCE

       To provide total flexibility Class::Accessor::Grouped calls methods internally while performing get/set
       actions, which makes it noticeably slower than similar modules. To compensate, this module will
       automatically use the insanely fast Class::XSAccessor to generate the "simple"-group accessors if this
       module is available on your system.

   Benchmark
       This is the benchmark of 200 get/get/set/get/set cycles on perl 5.16.2 with thread support, showcasing
       how this modules simple (CAG_S), inherited (CAG_INH) and inherited with parent-class data (CAG_INHP)
       accessors stack up against most popular accessor builders:  Moose, Moo, Mo, Mouse (both pure-perl and XS
       variant), Object::Tiny::RW (OTRW), Class::Accessor (CA), Class::Accessor::Lite (CAL),
       Class::Accessor::Fast (CAF), Class::Accessor::Fast::XS (CAF_XS) and Class::XSAccessor (XSA)

                             Rate CAG_INHP CAG_INH     CA  CAG_S    CAF  moOse   OTRW    CAL     mo  moUse HANDMADE    moo CAF_XS moUse_XS    XSA

        CAG_INHP  287.021+-0.02/s       --   -0.3% -10.0% -37.1% -53.1% -53.6% -53.7% -54.1% -56.9% -59.0%   -59.6% -59.8% -78.7%   -81.9% -83.5%

        CAG_INH  288.025+-0.031/s     0.3%      --  -9.7% -36.9% -52.9% -53.5% -53.5% -53.9% -56.7% -58.8%   -59.5% -59.7% -78.6%   -81.9% -83.5%

        CA       318.967+-0.047/s    11.1%   10.7%     -- -30.1% -47.9% -48.5% -48.5% -49.0% -52.1% -54.4%   -55.1% -55.3% -76.3%   -79.9% -81.7%

        CAG_S    456.107+-0.054/s    58.9%   58.4%  43.0%     -- -25.4% -26.3% -26.4% -27.0% -31.5% -34.8%   -35.8% -36.1% -66.1%   -71.3% -73.9%

        CAF      611.745+-0.099/s   113.1%  112.4%  91.8%  34.1%     --  -1.2%  -1.2%  -2.1%  -8.1% -12.6%   -14.0% -14.3% -54.5%   -61.5% -64.9%

        moOse    619.051+-0.059/s   115.7%  114.9%  94.1%  35.7%   1.2%     --  -0.1%  -1.0%  -7.0% -11.6%   -12.9% -13.3% -54.0%   -61.0% -64.5%

        OTRW       619.475+-0.1/s   115.8%  115.1%  94.2%  35.8%   1.3%   0.1%     --  -0.9%  -6.9% -11.5%   -12.9% -13.2% -54.0%   -61.0% -64.5%

        CAL      625.106+-0.085/s   117.8%  117.0%  96.0%  37.1%   2.2%   1.0%   0.9%     --  -6.1% -10.7%   -12.1% -12.5% -53.5%   -60.6% -64.2%

        mo         665.44+-0.12/s   131.8%  131.0% 108.6%  45.9%   8.8%   7.5%   7.4%   6.5%     --  -4.9%    -6.4%  -6.8% -50.5%   -58.1% -61.9%

        moUse       699.9+-0.15/s   143.9%  143.0% 119.4%  53.5%  14.4%  13.1%  13.0%  12.0%   5.2%     --    -1.6%  -2.0% -48.0%   -55.9% -59.9%

        HANDMADE   710.98+-0.16/s   147.7%  146.8% 122.9%  55.9%  16.2%  14.9%  14.8%  13.7%   6.8%   1.6%       --  -0.4% -47.2%   -55.2% -59.2%

        moo        714.04+-0.13/s   148.8%  147.9% 123.9%  56.6%  16.7%  15.3%  15.3%  14.2%   7.3%   2.0%     0.4%     -- -46.9%   -55.0% -59.1%

        CAF_XS   1345.55+-0.051/s   368.8%  367.2% 321.8% 195.0% 120.0% 117.4% 117.2% 115.3% 102.2%  92.2%    89.3%  88.4%     --   -15.3% -22.9%

        moUse_XS    1588+-0.036/s   453.3%  451.3% 397.9% 248.2% 159.6% 156.5% 156.3% 154.0% 138.6% 126.9%   123.4% 122.4%  18.0%       --  -9.0%

        XSA      1744.67+-0.052/s   507.9%  505.7% 447.0% 282.5% 185.2% 181.8% 181.6% 179.1% 162.2% 149.3%   145.4% 144.3%  29.7%     9.9%     --

       Benchmarking program is available in the root of the repository <http://search.cpan.org/dist/Class-
       Accessor-Grouped/>:

   Notes on Class::XSAccessor
       You can force (or disable) the use of Class::XSAccessor before creating a particular "simple" accessor by
       either manipulating the global variable $Class::Accessor::Grouped::USE_XS to true or false (preferably
       with localization, or you can do so before runtime via the "CAG_USE_XS" environment variable.

       Since Class::XSAccessor has no knowledge of "get_simple" and "set_simple" this module does its best to
       detect if you are overriding one of these methods and will fall back to using the perl version of the
       accessor in order to maintain consistency. However be aware that if you enable use of "Class::XSAccessor"
       (automatically or explicitly), create an object, invoke a simple accessor on that object, and then
       manipulate the symbol table to install a "get/set_simple" override - you get to keep all the pieces.

AUTHORS

       Matt S. Trout <mst@shadowcatsystems.co.uk>

       Christopher H. Laco <claco@chrislaco.com>

CONTRIBUTORS

       Caelum: Rafael Kitover <rkitover@cpan.org>

       frew: Arthur Axel "fREW" Schmidt <frioux@gmail.com>

       groditi: Guillermo Roditi <groditi@cpan.org>

       Jason Plum <jason.plum@bmmsi.com>

       ribasushi: Peter Rabbitson <ribasushi@cpan.org>

       Copyright (c) 2006-2010 Matt S. Trout <mst@shadowcatsystems.co.uk>

       This program is free software; you can redistribute it and/or modify it under the same terms as perl
       itself.