Attachments and Body Resources

[manveru]

This allows adding Attachments when specifying an Email.

The fields of Carbon::Attachment were chosen based on the ones required in the SMTP library carbon_smtp_adapter uses: https://github.com/arcage/crystal-email/blob/master/src/email/message.cr#L353-L382

I'd imagine the same data may be used by all other adapters.

example usage:

class TestEmail < BaseEmail
  from Carbon::Address.new("My App Name", "support@myapp.com")
  to "fred@example.org"
  subject "Test Subject"
  templates text, html
  attachment hello

  def bye
    {
      io: IO::Memory.new("Bye"),
      cid: "unique_bar@myapp.com",
      file_name: "bye.txt",
      mime_type: "text/plain"
    }
  end
end

Please note that I did fold both attachments and body resources into a single Array, this is mostly to keep our API simple, the only difference being the presence of the cid property.

[jwoertink]

This looks pretty simple for a start. The only thing I worry about is somebody calling that method and duplicating the attachements

email = SendReceiptEmail.new
total = email.attachements.size
email.attachements.each do |a|
  puts a
end

I think this could give weird results on the iteration because it would append the attachment again, right?

[manveru]

Attachments can be duplicated according to the spec. Except when you set the Content-ID, but in that case the upstream message_resource method will raise an exception about duplicated entries.

I didn't expect this will be much of an issue in practice, so I opted for not using a Hash, which simplifies our implementation a lot, given that there's not really a foolproof way to decide on a key for said Hash, and it would be a runtime error either way.