Action_mailer.default_url_options

A Rails question!

action_mailer.default_url_options is a configuration option in Rails that allows you to set default URL options for Action Mailer.

When you send an email using Action Mailer, you may need to include links or URLs in the email body. By default, Action Mailer uses the url_for method to generate these URLs. However, url_for requires a host and port to generate the URL.

default_url_options allows you to set default values for these options, so you don't have to specify them every time you use url_for in your email templates.

Here's an example of how you might use default_url_options:

# config/environments/production.rb
ActionMailer::Base.default_url_options = { host: 'example.com', port: 443 }

In this example, we're setting the default host to example.com and the default port to 443 (which is the default HTTPS port). This means that when you use url_for in your email templates, it will generate URLs with example.com as the host and 443 as the port.

You can also set default_url_options in your application.rb file, like this:

# config/application.rb
module MyApplication
  class Application < Rails::Application
    config.action_mailer.default_url_options = { host: 'example.com', port: 443 }
  end
end

This sets the default URL options for all Action Mailer instances in your application.

Note that you can also override default_url_options on a per-mailer basis by setting it in the mailer class itself. For example:

# app/mailers/user_mailer.rb
class UserMailer < ApplicationMailer
  default_url_options { { host: 'user.example.com', port: 443 } }
end

This sets the default URL options for the UserMailer class to user.example.com and 443.