fixing/breaking email::simple::creator

Email::Simple::Creator crams a create method into Email::Simple. It lets you provide an array of headers and a body, and it returns a new Email::Simple object.

I thought I’d have a quick run through Email::Simple::Creator to clean up some of its foibles. Here is another one that makes me wonder…

_add_to_header is called by the create method. A reference to a string is passed in, along with each name/value pair for the headers. _add_to_header appends a line to the string.

sub _add_to_header {
  my ($class, $header, $key, $value) = @_;
  return unless $value;
  ${$header} .= join(": ", $key, $value) . $CRLF;
}

That return unless $value is nuts! It means that you can’t create a message with “0” or “” as a header value. This is clearly a bug.

The problem is that unless a Date header is specified, one is generated and added. Currently if one specifies a false Date header, nothing is added, either the given (false) value or a generated value.

The code below creates a message with one header, Subject:

my $email = Email::Simple->create(
  header => [ Date => undef, Subject => 'foo' ],
  body   => "Hello sailor.",
);

If the bug is fixed in the way that seem obvious to me – use ‘’ for empty and undefined headers and 0 for literal zero headers – then people using constructs like the above will now have Date fields again – they’ll just be blank.

I don’t really like the idea of “undef is skipped but ‘’ is not.”

I am sort of leaning toward special-casing Date. It sucks, but it’s already a special case to begin with.

Written on February 26, 2007