aws_sns

Push Notification with AWS SNS Service

Prerequisites
1. Amazon account
2. Note Down the Amazon access_key_id, secret_access_key and region
3. Create an Application in Amazon/SNS Section
4. Note Down the Application Platform ARN
5. Set ENV variables:
	ENV['SNS_APP_ARN'] = the arn obtained from 4th step
	ENV['AWS_ACCESS_KEY_ID'] = obtained from step 2
	ENV['AWS_SECRET_ACCESS_KEY']= obtained from step 2

Getting Started with 'aws-sdk' gem 

1. Add gem 'aws-sdk'
2. bundle install
3. Set configuration for aws
	AWS.config(access_key_id: ENV['AWS_ACCESS_KEY_ID'], secret_access_key: ENV['AWS_SECRET_ACCESS_KEY'], region: <region>)
4. Create an sns object
	sns = AWS::SNS.new
5. Set sns client
	client = sns.client
6. Whenever device registers on your site get GCM registration id and store it in your database, and every time the gmc registration id changes subscribe it in SNS
  response = client.create_platform_endpoint token: gcm_registraion_id, platform_application_arn: ENV['SNS_APP_ARN']
  # the response will contain the end_point_arn for the device registered, which will be used in sending notifications
  device_arn = response[:endpoint_arn] # save it

Publishing Notification:

gcm_message = {collapse_key: "any_collapse_key", data: {key: "Value"}}
message = {"GCM"=> gcm_message.to_json}.to_json 

response = client.publish target_arn: "<device_arn>", message: message , message_structure: 'json'

Notification Sent!

Whenever gcm registration id changes remove the existing target_arn and add new one
To remove the existing target arn 
client.delete_endpoint(endpoint_arn: device_arn)

You can broad cast the notification with by creating topics and subscribing the arn to the particular topics and publish specifying topic_arn