Action Mailer Parameterized

Provides the option to parameterize mailers in order to share instance variable setup, processing, and common headers.

Consider this example that does not use parameterization:

class InvitationsMailer < ApplicationMailer def account_invitation(inviter, invitee) @account = inviter.account @inviter = inviter @invitee = invitee subject = "#{@inviter.name} invited you to their Basecamp (#{@account.name})" mail \ subject: subject, to: invitee.email_address, from: common_address(inviter), reply_to: inviter.email_address_with_name end def project_invitation(project, inviter, invitee) @account = inviter.account @project = project @inviter = inviter @invitee = invitee @summarizer = ProjectInvitationSummarizer.new(@project.bucket) subject = "#{@inviter.name.familiar} added you to a project in Basecamp (#{@account.name})" mail \ subject: subject, to: invitee.email_address, from: common_address(inviter), reply_to: inviter.email_address_with_name end def bulk_project_invitation(projects, inviter, invitee) @account = inviter.account @projects = projects.sort_by(&:name) @inviter = inviter @invitee = invitee subject = "#{@inviter.name.familiar} added you to some new stuff in Basecamp (#{@account.name})" mail \ subject: subject, to: invitee.email_address, from: common_address(inviter), reply_to: inviter.email_address_with_name end end InvitationsMailer.account_invitation(person_a, person_b).deliver_later 

Using parameterized mailers, this can be rewritten as:

class InvitationsMailer < ApplicationMailer before_action { @inviter, @invitee = params[:inviter], params[:invitee] } before_action { @account = params[:inviter].account } default to: -> { @invitee.email_address }, from: -> { common_address(@inviter) }, reply_to: -> { @inviter.email_address_with_name } def account_invitation mail subject: "#{@inviter.name} invited you to their Basecamp (#{@account.name})" end def project_invitation @project = params[:project] @summarizer = ProjectInvitationSummarizer.new(@project.bucket) mail subject: "#{@inviter.name.familiar} added you to a project in Basecamp (#{@account.name})" end def bulk_project_invitation @projects = params[:projects].sort_by(&:name) mail subject: "#{@inviter.name.familiar} added you to some new stuff in Basecamp (#{@account.name})" end end InvitationsMailer.with(inviter: person_a, invitee: person_b).account_invitation.deliver_later