require "active_support/descendants_tracker" module ActionMailer module Previews #:nodoc: extend ActiveSupport::Concern included do # Set the location of mailer previews through app configuration: # # config.action_mailer.preview_path = "#{Rails.root}/lib/mailer_previews" # mattr_accessor :preview_path, instance_writer: false # Enable or disable mailer previews through app configuration: # # config.action_mailer.show_previews = true # # Defaults to true for development environment # mattr_accessor :show_previews, instance_writer: false # :nodoc: mattr_accessor :preview_interceptors, instance_writer: false self.preview_interceptors = [ActionMailer::InlinePreviewInterceptor] end module ClassMethods # Register one or more Interceptors which will be called before mail is previewed. def register_preview_interceptors(*interceptors) interceptors.flatten.compact.each { |interceptor| register_preview_interceptor(interceptor) } end # Register an Interceptor which will be called before mail is previewed. # Either a class or a string can be passed in as the Interceptor. If a # string is passed in it will be constantized. def register_preview_interceptor(interceptor) preview_interceptor = \ case interceptor when String, Symbol interceptor.to_s.camelize.constantize else interceptor end unless preview_interceptors.include?(preview_interceptor) preview_interceptors << preview_interceptor end end end end class Preview extend ActiveSupport::DescendantsTracker class << self # Returns all mailer preview classes. def all load_previews if descendants.empty? descendants end # Returns the mail object for the given email name. The registered preview # interceptors will be informed so that they can transform the message # as they would if the mail was actually being delivered. def call(email) preview = self.new message = preview.public_send(email) inform_preview_interceptors(message) message end # Returns all of the available email previews. def emails public_instance_methods(false).map(&:to_s).sort end # Returns true if the email exists. def email_exists?(email) emails.include?(email) end # Returns true if the preview exists. def exists?(preview) all.any? { |p| p.preview_name == preview } end # Find a mailer preview by its underscored class name. def find(preview) all.find { |p| p.preview_name == preview } end # Returns the underscored name of the mailer preview without the suffix. def preview_name name.sub(/Preview$/, "").underscore end private def load_previews if preview_path Dir["#{preview_path}/**/*_preview.rb"].each { |file| require_dependency file } end end def preview_path Base.preview_path end def show_previews Base.show_previews end def inform_preview_interceptors(message) Base.preview_interceptors.each do |interceptor| interceptor.previewing_email(message) end end end end end