/ 
TableDataRoles-Standard-0.022
River stage two • 27 direct dependents • 42 total dependents
/ TableDataRole::Munge::GroupRows

NAME

TableDataRole::Munge::GroupRows - Role to group rows from another tabledata

VERSION

This document describes version 0.022 of TableDataRole::Munge::GroupRows (from Perl distribution TableDataRoles-Standard), released on 2024-01-15.

SYNOPSIS

To use this role and create a curried constructor:

package TableDataRole::Perl::CPAN::Release::Static::GroupedDaily;
use Role::Tiny;
with 'TableDataRole::Munge::GroupRows';
around new => sub {
    my $orig = shift;
    $orig->(@_,
        tabledata => 'Perl::CPAN::Release::Static',
        key => 'date',
        calc_key => sub {
            my $row = shift; # hashref
            $row->{date} =~ /\A(\d\d\d\d-\d\d-\d\d)/ or die; # extract YY-MM-DD from ISO8601 datetime
            $1;
        },
    );
};

package TableData::;Perl::CPAN::Release::Static::GroupedDaily;
use Role::Tiny::With;
with 'TableDataRole::Perl::CPAN::Release::Static::GroupedDaily';
1;

In code that uses your TableData class:

use TableData::Perl::CPAN::Release::GroupedDaily;

my $td = TableData::Perl::CPAN::Release::GroupedDaily->new;
...

DESCRIPTION

This role groups rows from another tabledata and returns a two-column table with these columns: $key, rows. The name of the key column can be customized via the constributor argument key, defaults to key if unspecified. The rows columns will contain the (arrayref of) original rows that are grouped under the single key value. You also need to provide calc_key to calculate the key value from a hashref row.

ROLES MIXED IN

TableDataRole::Spec::Basic

PROVIDED METHODS

new

Usage:

my $obj = $class->new(%args);

Constructor. Known arguments:

  • tabledata

    Required. Tabledata module name (without the TableData:: prefix) with optional arguments (see Module::Load::Util for more details).

  • key

    Name of key column. Default to key.

  • calc_key

    Required. Coderef to calculate key from hashref row. Codekey will be passed:

    ($row_hashref, $aoa)

    where $aoa is the grouped table data structure being constructed. This makes it possible to insert or delete rows as needed, e.g. when grouping by date, you can insert empty rows to close date gaps.

Note that if your class wants to wrap this constructor in its own, you need to create another role first, as shown in the example in Synopsis.

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/TableDataRoles-Standard.

SOURCE

Source repository is at https://github.com/perlancar/perl-TableDataRoles-Standard.

SEE ALSO

AUTHOR

perlancar <perlancar@cpan.org>

CONTRIBUTING

To contribute, you can send patches by email/via RT, or send pull requests on GitHub.

Most of the time, you don't need to build the distribution yourself. You can simply modify the code, then test via:

% prove -l

If you want to build the distribution (e.g. to try to install it locally on your system), you can install Dist::Zilla, Dist::Zilla::PluginBundle::Author::PERLANCAR, Pod::Weaver::PluginBundle::Author::PERLANCAR, and sometimes one or two other Dist::Zilla- and/or Pod::Weaver plugins. Any additional steps required beyond that are considered a bug and can be reported to me.

COPYRIGHT AND LICENSE

This software is copyright (c) 2024, 2023, 2022, 2021 by perlancar <perlancar@cpan.org>.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

BUGS

Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=TableDataRoles-Standard

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.