ActionMailerAutoPreviews

Enhances the ActionMailer Previews introduced in 4.1 by automatically creating ActionMailer Previews at runtime in development mode. See automatic previews of your ActionMailer emails, with no extra effort or mock data. Install the action_mailer_auto_previews gem into your :development group, and it'll 'just work' with sensible defaults. Each ActionMailer email object that has .deliver or .deliver_later called will automatically launch your default browser right to a ActionMailer Preview page with the real data passed to that email. Flexible options allow you to alter this behavior as well.

Warning: Since this is dynamically creating Ruby classes/methods, you will want to make sure your web-server is single threaded. For example, if you're using Puma, be sure to set the workers configuration parameter to 1.

Add this line to your application's Gemfile :development group:

group :development do
  gem 'action_mailer_auto_previews'
end

And then execute:

$ bundle

Or install it yourself as:

$ gem install action_mailer_auto_previews

That's it! Simply include the gem in your Gemfile's :development group, and by default, you will be able to automatically see previews of your ActionMailer emails. Whenever deliver or deliver_later is called on one of your ActionMailers, the gem will automatically generate the ActionMailer::Preview required and open the preview in your default browser. However, there are several configuration options that can be used to alter this behavior.

ActionMailerAutoPreviews.setup do |config|
  config.enabled = true
  config.history_limit = 10
  config.intercept_mode = :preview_only # [:preview_only, :preview_and_deliver]
  config.launch_browser = true
  config.logger = Rails.logger
  config.preview_host_url = "http://localhost:3000"
end

By default, the gem will be enabled in development mode. To have finer control, you can set config.enabled to false.

config.enabled = false # Set to false to disable

You can control how many automatic email previews are kept around for your viewing. By default, this is set to 10. You can see past automatic emails by visiting http://localhost:3000/rails/mailers/action_mailer_auto_previews.

config.history_limit = 50 # Keep 50 previews

The default behavior is to automatically launch your default browser to the newly generate email preview, and then suppress the default implementation of deliver or deliver_later. If you would like it to launch your browser and continue with the original deliver and deliver_later, simply set this configuration value to :preview_and_deliver

config.intercept_mode = :preview_and_deliver # Show preview and still "deliver"

You can configure whether or not your default browser launches automatically. The default configuration is to automatically launch, however, if you choose to disable this, the URL to the newly-available email preview will be logged to the configured logger.

config.launch_browser = false # Do not launch the default browser

When setting config.launch_browser = false, the URLs to the automatic email previews will be logged to the configured logger. By default, the logger is set to Rails.logger when Rails is detected, otherwise it will be Logger.new(STDOUT)

config.logger = Logger.new(STDOUT)

You can change the base URL that the gem uses to serve up the automatic email previews. This is helpful if you're not running your webserver on port 3000, or, you wish to use a different hostname, or any other reason.

config.preview_host_url = "http://localhost:5000"

Bug reports and pull requests are welcome on GitHub at https://github.com/makifund/action_mailer_auto_previews.

The gem is available as open source under the terms of the MIT License.