I'd like to upvote for this request as it enables more refactoring possibility from the caller side, as well as reducing surprises.
It's not uncommon that in a Web CMS of some sort, a DateTime object needs to be formatted in both machine-readable formats and human-readable format, sometimes in the same output. One use case of such is to produce a HTML <time> tag:
<time datetime="2020-04-06T00:00:00+0800">Yesterday</time>
Where the "datetime" attribute and the "Yesterday" should refer to the same moment, but in different formats.
Having a `format_datetime` method in this module enables developers to pre-construct a formatter object in controller and pass it to template -- without having to do this in in template:
if ($wanted_format eq "iso8601") { ... }
else { ... }
Arguably this is also not difficult as there is already a `iso8601` method defined in DateTime class -- and this where reducing surprises kicks in :)
For new comers who are looking for "how to format DateTime as iso8601" in CPAN -- chances are they find DateTime::Format::ISO8601 before they read sufficient amount of documentation of DateTime. They may try to use DateTime::Format::ISO8601 first and be surprised that it cannot do the job.
Perhaps I'm blind and not seeing drawbacks of adding the `format_datetime` method. -- let's discuss though.
So that's my 2c.
RT for rt.cpan.org