Gatling Gun is a library that helps you blast out a group of emails. It's a simple wrapper over SendGrid's Newsletter API.
If you want to use this code in a Rails application, just add it to your Gemfile:
gem "gatling_gun"
To use the code in a non-Rails application, first install the gem:
gem install gatling_gun
Then require the library in your code:
require "gatling_gun"
Either way, you will want to setup Gatling Gun as your application loads. I
recommend just setting a constant you can then refer to throughout your
application. In Rails, I would put the following code in
config/initializers/gatling_gun.rb. Setup is easy, just add you SendGrid
credentials:
SendGrid = GatlingGun.new("USERNAME", "PASSWORD")
The minimal steps to create and send a newsletter would be something like the following. First, you need an identity to send from:
SendGrid.add_identity( "test", name: "Test User",
email: "[email protected]",
address: "513 Cinnamon Dr.",
city: "Edmond",
state: "OK",
zip: "73003",
country: "USA" )
Then you can create a newsletter using that identity:
SendGrid.add_newsletter( "episode1", identity: "test",
subject: "Episode 1",
text: "The Text Body",
html: "<h1>The HTML Body</h1>" )
Next you need to create a list of recipients, add some emails to it, and attach that list to the newsletter:
SendGrid.add_list("subscribers")
SendGrid.add_emails( "subscribers", [ { name: "James Edward Gray II",
email: "[email protected]" },
{ name: "Admin",
email: "[email protected]" } ] )
SendGrid.add_recipients("episode1", "subscribers")
Of course, you could reuse identities and recipient lists for future newsletter messages without needing to recreate them.
Finally, you can schedule when to have the message sent:
SendGrid.add_schedule("episode1", at: Time.now + 10 * 60)
That would sent it 10 minutes from now, but you can adjust the time to whenever you desire or even leave it out to send now.