DBIx::Class::DynamicDefault - Automatically set and update fields

DBIx-Class-DynamicDefault documentation Contained in the DBIx-Class-DynamicDefault distribution.

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NAME

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DBIx::Class::DynamicDefault - Automatically set and update fields

SYNOPSIS

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  package My::Schema::SomeTable;

  __PACKAGE__->load_components(qw/DynamicDefault ... Core/);

  __PACKAGE__->add_columns(
          quux          => { data_type => 'integer' },
          quux_plus_one => { data_type => 'integer',
                             dynamic_default_on_create => \&quux_plus_one_default,
                             dynamic_default_on_update => 'quux_plus_one_default', },
          last_changed  => { data_type => 'integer',
                             dynamic_default_on_create => 'now',
                             dynamic_default_on_update => 'now, },
  );

  sub quux_plus_one_default {
      my ($self) = @_;
      return $self->quux + 1;
  }

  sub now {
      return DateTime->now->epoch;
  }

Now, any update or create actions will set the specified columns to the value returned by the callback you specified as a method name or code reference.

DESCRIPTION

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Automatically set and update fields with values calculated at runtime.

OPTIONS

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dynamic_default_on_create

  dynamic_default_on_create => sub { ... }

  dynamic_default_on_create => 'method_name'

When inserting a new row all columns with the dynamic_default_on_create option will be set to the return value of the specified callback unless the columns value has been explicitly set. The callback, that'll be invoked with the row object as its only argument, may be a code reference or a method name.

dynamic_default_on_update

  dynamic_default_on_update => sub { ... }

  dynamic_default_on_update => 'method_name'

When updating a row all columns with the dynamic_default_on_update option will be set to the return value of the specified callback unless the columns value has been explicitly set.

Columns will only be altered if other dirty columns exist. See always_update on how to change this.

always_update

  always_update => 1

When setting always_update to 1 dynamic_default_on_update callbacks will always be invoked, even if no other columns are dirty.

AUTHOR

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Florian Ragwitz <rafl@debian.org>

LICENSE

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This software is copyright (c) 2008 by Florian Ragwitz.

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

DBIx-Class-DynamicDefault documentation Contained in the DBIx-Class-DynamicDefault distribution. 
use strict;
use warnings;

package DBIx::Class::DynamicDefault;

use parent 'DBIx::Class';

our $VERSION = '0.03';

__PACKAGE__->mk_classdata(
    __column_dynamic_default_triggers => {
        on_update => [], on_create => [],
    },
);


sub add_columns {
    my $self = shift;

    $self->next::method(@_);

    my @update_columns;
    my @create_columns;

    for my $column ($self->columns) {
        my $info = $self->column_info($column);

        my $update_trigger = $info->{dynamic_default_on_update};
        push @update_columns, [$column => $update_trigger, $info->{always_update} || 0]
            if $update_trigger;

        my $create_trigger = $info->{dynamic_default_on_create};
        push @create_columns, [$column => $create_trigger]
            if $create_trigger;
    }

    if (@update_columns || @create_columns) {
        $self->__column_dynamic_default_triggers({
            on_update => [sort { $b->[2] <=> $a->[2] } @update_columns],
            on_create => \@create_columns,
        });
    }
}

sub insert {
    my $self = shift;

    my @columns = @{ $self->__column_dynamic_default_triggers->{on_create} };
    for my $column (@columns) {
        my $column_name = $column->[0];
        next if defined $self->get_column($column_name);

        my $meth = $column->[1];
        my $default_value = $self->$meth;

        my $accessor = $self->column_info($column_name)->{accessor} || $column_name;
        $self->$accessor($default_value);
    }

    return $self->next::method(@_);
}

sub update {
    my ($self, $upd) = @_;

    $self->set_inflated_columns($upd) if $upd;
    my %dirty = $self->get_dirty_columns;

    my @columns = @{ $self->__column_dynamic_default_triggers->{on_update} };
    for my $column (@columns) {
        my $column_name = $column->[0];
        next if !%dirty && !$column->[2];
        next if exists $dirty{$column_name};

        my $meth = $column->[1];
        my $default_value = $self->$meth;

        my $accessor = $self->column_info($column_name)->{accessor} || $column_name;
        $self->$accessor($default_value);

        $dirty{$column_name} = 1;
    }

    return $self->next::method;
}


1;