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Data-Transfigure-1.01
River stage zero No dependents
++
/ Data::Transfigure

NAME

Data::Transfigure - performs rule-based data transfigurations of arbitrary structures

SYNOPSIS

    use Data::Transfigure;

    my $d = Data::Transfigure->std();
    $d->add_transfigurators(qw(
      Data::Transfigure::Type::DateTime::Duration
      Data::Transfigure::HashKeys::CamelCase
    ), Data::Transfigure::Type->new(
      type    => 'Activity::Run'.
      handler => sub ($data) {
        {
          start    => $data->start_time, # DateTime
          time     => $data->time,       # DateTime::Duration
          distance => $data->distance,   # number
          pace     => $data->pace,       # DateTime::Duration
        }
      }
    ));

    my $list = [
      { user_id => 3, run  => Activity::Run->new(...) },
      { user_id => 4, ride => Activity::Ride->new(...) },
    ];

    $d->transfigure($list); # [
                          #   {
                          #     userID => 3
                          #     run    => {
                          #                 start    => "2023-05-15T074:11:14",
                          #                 time     => "PT30M5S",
                          #                 distance => "5",
                          #                 pace     => "PT9M30S",
                          #               }
                          #   },
                          #   {
                          #     userID => 4,
                          #     ride   => "Activity::Ride=HASH(0x2bbd7d16f640)",
                          #   },
                          # ]

DESCRIPTION

Data::Transfigure allows you to write reusable rules ('transfigurators') to modify parts (or all) of a data structure. There are many possible applications of this, but it was primarily written to handle converting object graphs of ORM objects into a structure that could be converted to JSON and delivered as an API endpoint response. One of the challenges of such a system is being able to reuse code because many different controllers could need to convert the an object type to the same structure, but then other controllers might need to convert that same type to a different structure.

A number of transfigurator roles and classes are included with this distribution:

CONSTRUCTORS

Data::Transfigure->new()

Constructs a new default instance that pre-adds Data::Transfigure::Default::ToString to stringify values that are not otherwise transfigured by user-provided transfigurators. Preserves (does not transfigure to empty string) undefined values.

Data::Transfigure->bare()

Returns a "bare-bones" instance that has no builtin data transfigurators.

Data::Transfigure->dbix()

Adds Data::Transfigure::DBIx::Recursive to to handle DBIx::Class result rows

METHODS

add_transfigurators( @list )

Registers one or more data transfigurators with the Data::Transfigure instance.

    $t->add_transfigurators(Data::Transfigure::Type->new(
      type    => 'DateTime',
      handler => sub ($data) {
        $data->strftime('%F')
      }
    ));

Each element of @list must implement the Data::Transfigure::Node role, though these can either be strings containing class names or object instances.

Data::Transfigure will automatically load class names passed in this list and construct an object instance from that class. This will fail if the class's new constructor does not exist or has required parameters.

    $t->add_transfigurators(qw(Data::Transfigure::Type::DateTime Data::Transfigure::Type::DBIx));

ArrayRefs passed in this list will be expanded and their contents will be treated the same as any item passed directly to this method.

    my $default = Data::Transfigure::Type::Default->new(
      handler => sub ($data) {
        "[$data]"
      }
    );
    my $bundle = [q(Data::Transfigure::Type::DateTime), $default];
    $t->add_transfigurators($bundle);

When transfiguring data, only one transfigurator will be applied to each data element, prioritizing the most-specific types of matches. Among transfigurators that have equal match types, those added later have priority over those added earlier.

add_transfigurator_at( $position => $transfigurator )

add_transfigurator_at is a convenience method for creating and adding a positional transfigurator (one that applies to a specific data-path within the given structure) in a single step.

See Data::Transfigure::Position for more on positional transfigurators.

transfigure( $data )

Transfigures the data according to the transfigurators added to the instance and returns it. The data structure passed to the method is unmodified.

AUTHOR

Mark Tyrrell <mark@tyrrminal.dev>

LICENSE

Copyright (c) 2024 Mark Tyrrell

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.