Using this gem with Rails should be documented

[skalee]

This gem works with Rails nicely, however it requires a small additional step, which isn't obvious. A short README section is required at minimum.

For reference, the easiest way to use EnMail in Rails is to register an interceptor. Voilà:

class CryptoInterceptor
  def self.delivering_email(message)
    adapter = EnMail::Adapters::RNP
    EnMail.protect :sign, message, adapter: adapter
  end
end

ActionMailer::Base.register_interceptor(CryptoInterceptor)

[skalee]

Also for reference, some full example which works as expected if executed in EnMail's root directory, provided that keys have been generated with rake pgp_keys:generate:

$LOAD_PATH.unshift File.expand_path("lib", __dir__)
$PGP_HOME = File.expand_path("tmp/pgp_home", __dir__)

require "action_mailer"
require "enmail"

class ExampleMailer < ActionMailer::Base
  def carthage
    mail(
      to: "Roman Senate <senate@example.test>",
      from: "Cato Elder <cato.elder@example.test>",
      subject: "About Carthage",
      body: "Must be destroyed!",
    )
  end
end

class CryptoInterceptor
  def self.delivering_email(message)
    adapter = EnMail::Adapters::RNP
    EnMail.protect :sign, message, adapter: adapter, homedir: $PGP_HOME
  end
end

ActionMailer::Base.delivery_method = :test
ActionMailer::Base.register_interceptor(CryptoInterceptor)

ExampleMailer.carthage.deliver_now

puts ActionMailer::Base.deliveries.first.encoded