Multi-Channel Notifications in Ruby on Rails with Noticed gem and Pushpad

In this tutorial we explain how to use the pushpad gem with the noticed gem to create multi-channel notifications in a Rails application. In particular we'll use the noticed gem for the notifications in general, while Pushpad will be used to deliver the web push notifications in real time, even when the website is closed.

Pushpad has an official library for Ruby and most Rails applications can simply use that library for sending web push notifications. However it is also possible to use Pushpad together with other delivery methods: website, email, sms, etc. In this complex scenario, where multiple channels are used, a gem like noticed can be useful.

For example, in this tutorial, we want to notify the author of a post of any new comments on his post. We'll first try to notify the author using the website and push notifications, then, after some time, we'll fallback to email if the notifications are not read.

Install and configure the noticed gem

Install the noticed gem as described in the official documentation.

We'll use this gem for creating the notifications in the database, displaying them in the website and tracking when a notification is read.

Basically you need to add the gem to your application:

gem 'noticed'

Then generate the required files and complete the installation:

rails generate noticed:model

And finally we can generate a model for our notifications:

rails generate noticed:notification CommentNotification

Install and configure the pushpad gem

Install the pushpad gem as described in the official documentation.

We'll use this gem for sending the push notifications and reaching the user even when the website is closed.

Basically you need to add the gem to your application:

gem 'pushpad'

Then set the authentication credentials (in an initializer):

Pushpad.auth_token = Rails.application.credentials.pushpad_auth_token
Pushpad.project_id = 12345

Integration between the noticed gem and pushpad gem

The noticed gem can deliver the same notification using different means: database, action cable, email, sms, etc.

Now we are going to add a new delivery method: Pushpad and web push notifications.

Run this command:

rails generate noticed:delivery_method Pushpad

Then open the new file located in the app/notifications/delivery_methods folder and add this content:

class DeliveryMethods::Pushpad < Noticed::DeliveryMethods::Base

  def deliver
    Pushpad::Notification.new(format).deliver_to recipient
  end

  private

  def format
    notification.send(options[:format])
  end

end

Now the noticed gem can deliver the notifications using this new strategy.

Sending the notifications

Let's finish the CommentNotification class:

class CommentNotification < Noticed::Base
  deliver_by :database
  deliver_by :pushpad, class: 'DeliveryMethods::Pushpad', format: :pushpad_format
  deliver_by :email, mailer: 'UserMailer', delay: 1.hour, if: :unread?

  # Customize notification
  # See https://github.com/pushpad/pushpad-ruby#sending-push-notifications
  def pushpad_format
    comment = params[:comment]
    {
      title: "#{comment.user.name} replied to your post",
      body: comment.body,
      target_url: post_url(comment.post)
    }
  end
end

This class saves the notification in the database (e.g. to display it in the website), it sends a web push notification using Pushpad, and finally uses the email after some time if the notification is not read.

In this way the author of the post we'll never miss the comments on his post.

Finally in your models or controllers, when a new comment is posted, you can create a notification with this code:

notification = CommentNotification.with(comment: @comment)
notification.deliver_later(@comment.post.author)

Subscribe the users to web push notifications

The above code is complete, however your users are not subscribed to the web push notifications yet.

In order to add the notifications to your website, follow the Getting Started Tutorial.

Then you can use the Pushpad JavaScript SDK to subscribe the users to your notifications.

This command subscribes the browser to the notifications and attaches a user ID (uid) that is used for targeting this specific user with notifications:

pushpad('subscribe', function () {}, { uid: 'myUser123' });

We also recommend to check out this resources for more information:

• Targeting specific users with web push notifications

• Javascript SDK reference

• Javascript SDK examples

Conclusion

That's it.

In the above example we have shown a way to notify comments on a post, but the process is similar for any other kind of notification. You just need to create another class (e.g. LikeNotification, DirectMessageNotification, FollowNotification) and add deliver_by :pushpad.

Now you can easily add multi-channel notifications to any Rails application.