Apple Push Notifications with Heroku

Most people think they can't deliver push notifications to iOS devices from Heroku because there is no obvious way to maintain maintain a persistent connection. I started by looking at Urban Airship and other push services, but decided to see how far I could get with Heroku. You will find that Heroku takes the cake and steals the “easy-to-use push notification” tag line from Urban Airship.

In my case I used the APN on Rails gem in combination with Resque. Here is a quick peek at the code:

class Jobs::APN::DeliverNotifications
  @queue = "apn"

  def self.perform
    APN::Notification.send_notifications
  end

end

And that is just about it! Resque Scheduler is set to run this task every min. If there are no notifications, nothing is sent, otherwise all of the notifications that have built up over the last minute get sent out in a batch.

This solution has worked for just about a year and is dead simple.

Processing APN feedback is dead simple too:

class Jobs::APN::Feedback < Job
  @queue = "#{RAILS_ENV}::apn"

  def self.perform
    APN::Feedback.process_devices
  end

end

Here is what a controller would look like. This handles the registering of an iOS device, subscribing, and unsubscribing from certain events:

class Api::ApnController < ApplicationController
  skip_before_filter :verify_authenticity_token

  def create
    APN::Device.create(:token => params[:token])
    render :text => "", :status => 200
  end

  def subscribe
    device = params['token'] ? APN::Device.find_or_create_by_token(:token => params['token']) : nil
    event = Event.first(:conditions => {:id => params['event_id']})
    subscription = Subscription.new :device => device, :event => event

    status = 200
    if device && event && subscription.valid?
      subscription.save
    else
      status = 422
    end
    render :text => "", :status => status
  end

  def unsubscribe
    device = APN::Device.find_or_create_by_token(:token => params['token'])
    event = Event.first(:conditions => {:id => params['event_id']})
    subscription = Subscription.first(:conditions => {:device_id => device.id, :event_id => event.id})
    subscription.delete if subscription
    render :text => "", :status => 200
  end

end

Simple.