Add mailer previews feature based on mail_view gem

actionmailer/CHANGELOG.md

@@ -1,3 +1,7 @@
*   Add mailer previews feature based on 37 Signals mail_view gem

    *Andrew White*

*   Calling `mail()` without arguments serves as getter for the current mail
    message and keeps previously set headers.

actionmailer/lib/action_mailer.rb

@@ -41,6 +41,8 @@ module ActionMailer
  autoload :Base
  autoload :DeliveryMethods
  autoload :MailHelper
  autoload :Preview
  autoload :Previews, 'action_mailer/preview'
  autoload :TestCase
  autoload :TestHelper
end

actionmailer/lib/action_mailer/base.rb

@@ -308,6 +308,25 @@ module ActionMailer
  # Note that unless you have a specific reason to do so, you should prefer using before_action
  # rather than after_action in your ActionMailer classes so that headers are parsed properly.
  #
  # = Previewing emails
  #
  # You can preview your email templates visually by adding a mailer preview file to the
  # <tt>ActionMailer::Base.preview_path</tt>. Since most emails do something interesting
  # with database data, you'll need to write some scenarios to load messages with fake data:
  #
  #   class NotifierPreview < ActionMailer::Preview
  #     def welcome
  #       Notifier.welcome(User.first)
  #     end
  #   end
  #
  # Methods must return a Mail::Message object which can be generated by calling the mailer
  # method without the additional <tt>deliver</tt>. The location of the mailer previews
  # directory can be configured using the <tt>preview_path</tt> option which has a default
  # of <tt>test/mailers/previews</tt>:
  #
  #     config.action_mailer.preview_path = "#{Rails.root}/lib/mailer_previews"
  #
  # = Configuration options
  #
  # These options are specified on the class level, like
@@ -362,6 +381,7 @@ module ActionMailer
  #   <tt>delivery_method :test</tt>. Most useful for unit and functional testing.
  class Base < AbstractController::Base
    include DeliveryMethods
    include Previews

    abstract!

actionmailer/lib/action_mailer/preview.rb

@@ -0,0 +1,67 @@
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"
      #
      class_attribute :preview_path, instance_writer: false
    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
      def call(email)
        preview = self.new
        preview.public_send(email)
      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

      protected
        def load_previews #:nodoc:
          Dir["#{preview_path}/**/*_preview.rb"].each{ |file| require_dependency file }
        end

        def preview_path #:nodoc:
          Base.preview_path
        end
    end
  end
end

actionmailer/lib/action_mailer/railtie.rb

@@ -40,5 +40,13 @@ class Railtie < Rails::Railtie # :nodoc:
        config.compile_methods! if config.respond_to?(:compile_methods!)
      end
    end

    initializer "action_mailer.configure_mailer_previews", before: :set_autoload_paths do |app|
      if Rails.env.development?
        options = app.config.action_mailer
        options.preview_path ||= defined?(Rails.root) ? "#{Rails.root}/test/mailers/previews" : nil
        app.config.autoload_paths << options.preview_path
      end
    end
  end
end

actionpack/lib/action_dispatch/routing/inspector.rb

@@ -69,7 +69,7 @@ def action
      end

      def internal?
        controller.to_s =~ %r{\Arails/(info|welcome)} || path =~ %r{\A#{Rails.application.config.assets.prefix}}
        controller.to_s =~ %r{\Arails/(info|mailers|welcome)} || path =~ %r{\A#{Rails.application.config.assets.prefix}}
      end

      def engine?

railties/lib/rails.rb

@@ -25,6 +25,7 @@ module Rails

  autoload :Info
  autoload :InfoController
  autoload :MailersController
  autoload :WelcomeController

  class << self

railties/lib/rails/application/finisher.rb

@@ -22,6 +22,8 @@ module Finisher
      initializer :add_builtin_route do |app|
        if Rails.env.development?
          app.routes.append do
            get '/rails/mailers'         => "rails/mailers#index"
            get '/rails/mailers/*path'   => "rails/mailers#preview"
            get '/rails/info/properties' => "rails/info#properties"
            get '/rails/info/routes'     => "rails/info#routes"
            get '/rails/info'            => "rails/info#index"

railties/lib/rails/generators/test_unit/mailer/mailer_generator.rb

@@ -4,11 +4,18 @@ module TestUnit # :nodoc:
  module Generators # :nodoc:
    class MailerGenerator < Base # :nodoc:
      argument :actions, type: :array, default: [], banner: "method method"
      check_class_collision suffix: "Test"

      def check_class_collision
        class_collisions "#{class_name}Test", "#{class_name}Preview"
      end

      def create_test_files
        template "functional_test.rb", File.join('test/mailers', class_path, "#{file_name}_test.rb")
      end

      def create_preview_files
        template "preview.rb", File.join('test/mailers/previews', class_path, "#{file_name}_preview.rb")
      end
    end
  end
end

railties/lib/rails/generators/test_unit/mailer/templates/preview.rb

@@ -0,0 +1,11 @@
<% module_namespacing do -%>
class <%= class_name %>Preview < ActionMailer::Preview
<% actions.each do |action| -%>

  def <%= action %>
    <%= class_name %>.<%= action %>
  end
<% end -%>

end
<% end -%>

railties/lib/rails/mailers_controller.rb

@@ -0,0 +1,73 @@
require 'rails/application_controller'

class Rails::MailersController < Rails::ApplicationController # :nodoc:
  prepend_view_path ActionDispatch::DebugExceptions::RESCUES_TEMPLATE_PATH

  before_filter :require_local!
  before_filter :find_preview, only: :preview

  def index
    @previews = ActionMailer::Preview.all
    @page_title = "Mailer Previews"
  end

  def preview
    if params[:path] == @preview.preview_name
      @page_title = "Mailer Previews for #{@preview.preview_name}"
      render action: 'mailer'
    else
      email = File.basename(params[:path])

      if @preview.email_exists?(email)
        @email = @preview.call(email)

        if params[:part]
          part_type = Mime::Type.lookup(params[:part])

          if part = find_part(part_type)
            response.content_type = part_type
            render text: part.respond_to?(:decoded) ? part.decoded : part
          else
            raise AbstractController::ActionNotFound, "Email part '#{part_type}' not found in #{@preview.name}##{email}"
          end
        else
          @part = find_preferred_part(request.format, Mime::HTML, Mime::TEXT)
          render action: 'email', layout: false, formats: %w[html]
        end
      else
        raise AbstractController::ActionNotFound, "Email '#{email}' not found in #{@preview.name}"
      end
    end
  end

  protected
    def find_preview
      candidates = []
      params[:path].to_s.scan(%r{/|$}){ candidates << $` }
      preview = candidates.detect{ |candidate| ActionMailer::Preview.exists?(candidate) }

      if preview
        @preview = ActionMailer::Preview.find(preview)
      else
        raise AbstractController::ActionNotFound, "Mailer preview '#{params[:path]}' not found"
      end
    end

    def find_preferred_part(*formats)
      if @email.multipart?
        formats.each do |format|
          return find_part(format) if @email.parts.any?{ |p| p.mime_type == format }
        end
      else
        @email
      end
    end

    def find_part(format)
      if @email.multipart?
        @email.parts.find{ |p| p.mime_type == format }
      elsif @email.mime_type == format
        @email
      end
    end
end

railties/lib/rails/templates/layouts/application.html.erb

@@ -29,7 +29,12 @@
  </style>
</head>
<body>
<h2>Your App: <%= link_to 'properties', '/rails/info/properties' %> | <%= link_to 'routes', '/rails/info/routes' %></h2>
<h2>
  Your App:
  <%= link_to 'mailers', '/rails/mailers' %> |
  <%= link_to 'properties', '/rails/info/properties' %> |
  <%= link_to 'routes', '/rails/info/routes' %>
</h2>
<%= yield %>

</body>

railties/lib/rails/templates/rails/mailers/email.html.erb

@@ -0,0 +1,98 @@
<!DOCTYPE html>
<html><head>
<meta name="viewport" content="width=device-width" />
<style type="text/css">
  header {
    width: 100%;
    padding: 10px 0 0 0;
    margin: 0;
    background: white;
    font: 12px "Lucida Grande", sans-serif;
    border-bottom: 1px solid #dedede;
    overflow: hidden;
  }

  dl {
    margin: 0 0 10px 0;
    padding: 0;
  }

  dt {
    width: 80px;
    padding: 1px;
    float: left;
    clear: left;
    text-align: right;
    color: #7f7f7f;
  }

  dd {
    margin-left: 90px; /* 80px + 10px */
    padding: 1px;
  }

  iframe {
    border: 0;
    width: 100%;
    height: 800px;
  }
</style>
</head>

<body>
<header>
  <dl>
    <% if @email.respond_to?(:smtp_envelope_from) && Array(@email.from) != Array(@email.smtp_envelope_from) %>
      <dt>SMTP-From:</dt>
      <dd><%= @email.smtp_envelope_from %></dd>
    <% end %>

    <% if @email.respond_to?(:smtp_envelope_to) && @email.to != @email.smtp_envelope_to %>
      <dt>SMTP-To:</dt>
      <dd><%= @email.smtp_envelope_to %></dd>
    <% end %>

    <dt>From:</dt>
    <dd><%= @email.header['from'] %></dd>

    <% if @email.reply_to %>
      <dt>Reply-To:</dt>
      <dd><%= @email.header['reply-to'] %></dd>
    <% end %>

    <dt>To:</dt>
    <dd><%= @email.header['to'] %></dd>

    <% if @email.cc %>
      <dt>CC:</dt>
      <dd><%= @email.header['cc'] %></dd>
    <% end %>

    <dt>Date:</dt>
    <dd><%= Time.current.rfc2822 %></dd>

    <dt>Subject:</dt>
    <dd><strong><%= @email.subject %></strong></dd>

    <% unless @email.attachments.nil? || @email.attachments.empty? %>
      <dt>Attachments:</dt>
      <dd>
        <%= @email.attachments.map { |a| a.respond_to?(:original_filename) ? a.original_filename : a.filename }.inspect %>
      </dd>
    <% end %>

    <% if @email.multipart? %>
      <dd>
        <select onchange="document.getElementsByName('messageBody')[0].src=this.options[this.selectedIndex].value;">
          <option <%= request.format == Mime::HTML ? 'selected' : '' %> value="?part=text%2Fhtml">View as HTML email</option>
          <option <%= request.format == Mime::TEXT ? 'selected' : '' %> value="?part=text%2Fplain">View as plain-text email</option>
        </select>
      </dd>
    <% end %>
  </dl>
</header>

<iframe seamless name="messageBody" src="?part=<%= Rack::Utils.escape(@part.mime_type) %>"></iframe>

</body>
</html>

railties/lib/rails/templates/rails/mailers/index.html.erb

@@ -0,0 +1,8 @@
<% @previews.each do |preview| %>
<h3><%= link_to preview.preview_name.titleize, "/rails/mailers/#{preview.preview_name}" %></h3>
<ul>
<% preview.emails.each do |email| %>
<li><%= link_to email, "/rails/mailers/#{preview.preview_name}/#{email}" %></li>
<% end %>
</ul>
<% end %>

railties/lib/rails/templates/rails/mailers/mailer.html.erb

@@ -0,0 +1,6 @@
<h3><%= @preview.preview_name.titleize %></h3>
<ul>
<% @preview.emails.each do |email| %>
<li><%= link_to email, "/rails/mailers/#{@preview.preview_name}/#{email}" %></li>
<% end %>
</ul>