Types::DateTime, DateTimeUTC->plus_coercions( Format['ISO8601'] ), output format override question

Your Mother has asked for the wisdom of the Perl Monks concerning the following question:

This terrific stuff— Types::DateTime, tobyink—is going into something I’m working on. Out of the box it is parsing perfectly–

use 5.12.0;
package CowTime {
    use Moo;
    use Types::DateTime -all;
    has timestamp =>
        is => "ro",
        isa => DateTimeUTC->plus_coercions( Format['ISO8601'] ),
        coerce => 1;
    1;
};

my $original = "2019-12-07T00:07:40.587596283-05:00";
my $cowtime = CowTime->new( timestamp => $original );

say $original;
say $cowtime->timestamp->time_zone;
say $cowtime->timestamp->nanosecond;
say $cowtime->timestamp;

__END__
2019-12-07T00:07:40.587596283-05:00
2019-12-07T05:07:40
DateTime::TimeZone::UTC=HASH(0x7f9e85ba3cd0)
587596283
[download]

It’s pulling apart the input perfectly but the output is the standard format and I’m looking for the “extended” format of the input such that the stringification will roundtrip to the form with the offset and the nanoseconds. I was set to code dive and look for the formatting hooks but I thought this was a really interesting package and wanted to put it up here. Also, I am lazy.

Comment on Types::DateTime, DateTimeUTC->plus_coercions( Format['ISO8601'] ), output format override question Download Code

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Re: Types::DateTime, DateTimeUTC->plus_coercions( Format['ISO8601'] ), output format override question by tobyink (Canon) on Dec 24, 2019 at 22:03 UTC
As per ikegami's answer (Re: Types::DateTime, DateTimeUTC->plus_coercions( Format['ISO8601'] ), output format override question), you want to set a formatter on the DateTime object. `$cowtime->timestamp->set_formatter($formatter);` [download] But you probably want your CowTime class to be doing that automatically. You can do that with triggers: `use 5.12.0; package CowTime { use Moo; use Types::DateTime -all; has timestamp => is => "ro", isa => DateTimeUTC->plus_coercions( Format['ISO8601'] ), coerce => 1, trigger => sub { my ($self, $value) = @_; state $formatter = DateTime::Format::MyFormatter->new; $value->set_formatter($formatter); }; 1; };` [download] The trigger is a coderef which gets called any time you set the value of an attribute. (Though it's not set if the attribute is set by a default/builder.) toby döt ink	[reply] [d/l] [select]
Re^2: Types::DateTime, DateTimeUTC->plus_coercions( Format['ISO8601'] ), output format override question by ikegami (Patriarch) on Dec 26, 2019 at 09:04 UTC
Though it's not set if the attribute is set by a default/builder. That makes this a particularly bad solution, then.	[reply]
Re^3: Types::DateTime, DateTimeUTC->plus_coercions( Format['ISO8601'] ), output format override question by tobyink (Canon) on Dec 26, 2019 at 09:26 UTC
Why? OP isn't using a default or builder. (Not in the example anyway.) toby döt ink	[reply]
Re^4: Types::DateTime, DateTimeUTC->plus_coercions( Format['ISO8601'] ), output format override question by ikegami (Patriarch) on Dec 27, 2019 at 05:54 UTC
Re^5: Types::DateTime, DateTimeUTC->plus_coercions( Format['ISO8601'] ), output format override question by tobyink (Canon) on Dec 27, 2019 at 16:40 UTC
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Re: Types::DateTime, DateTimeUTC->plus_coercions( Format['ISO8601'] ), output format override question by ikegami (Patriarch) on Dec 24, 2019 at 14:39 UTC
`$cowtime->timestamp` is a DateTime object, so you could use the following: `$cowtime->timestamp->strftime("%Y-%m-%dT%H:%M:%S.%9N%z") =~ s/(?=..\z) +/:/sr` [download] I'm not aware of any DateTime::Format::* class that would produce the format you want. If there was you could set it as the default format (used for stringification) using the following: `use DateTime::Format::Foo qw( ); my $format = DateTime::Format::Foo->new(...); $cowtime->timestamp->set_formatter($format);` [download]	[reply] [d/l] [select]