Salesforce Durable Streaming Demo

This repository contains all the code you need to set up a Durable PushTopic Streaming and a Durable Generic Streaming client inside of Visualforce pages in your Salesforce org. Durable Streaming adds the capability to replay any of the messages sent to the PushTopic for the last 24 hours.

This is handled through the use of a Replay ID. Every event sent through the Streaming API will have an associated ID. With Durable Streaming, you will have the ability to provide a Replay ID (ostensibly the last ID that your client has received) and the system will send every event that has happened in the last 24 hours after that specific ID.

If you do not provide an ID, or the ID you provide is -1, your client will be subscribed to the tip of the queue (you will receive all new messages). If you provide an ID of -2, we resend ALL events that happened in the last 24 hours.

Initial Setup Instructions

1. Download this repo as a zip file
   • The zip file contains all of the needed code to run the client inside of Salesforce
2. Deploy the code to a Summer '16 that has the API enabled org using the MdAPI through Workbench, Force.com IDE, or Ant Migration Tool
3. Assign the included DurableStreamingDemo permission set to your user

Durable PushTopic Demo Instructions

1. Create the /topic/TestAccountStreaming PushTopic by doing one of the following:
   • Open the Durable Streaming Demo app and click the Durable PushTopic Streaming Demo tab
   • Navigate to /apex/DurablePushTopicStreamingDemo. When the Visualforce page is loaded, it creates the PushTopic, and then auto-subscribes to /topic/TestAccountStreaming using Durable PushTopic Streaming.
2. Create notifications for the new topic
   • Use the on-screen utility to create, update and then delete an Account record
   • Or, use the UI or API to create, update, delete or undelete an Account record
3. Observe events being received in bottom panel
4. Update replay subscription settings by changing the Replay From attribute. The replay option changes where your subscription starts in the event stream:
   • -2 replays from the earliest available event
   • -1 (or no ID) replays only new events
   • A specific Replay ID replays all events after that specific ID

Durable Generic Demo Instructions

1. Create the /u/TestStreaming StreamingChannel by subscribing to that channel name
   • You can create the channel by using the Workbench and going to Queries > Streaming Push Topics and selecting Generic Subscriptions. Enter the subscription as /u/TestStreaming and click 'Subscribe' (this will create the channel)
2. Push an event to the new channel
   • Query the ID of the channel by using the Workbench REST Explorer and doing a GET to /services/data/v37.0/sobjects/StreamingChannel. In the response, expand recentItems to find the ID of the TestStreaming channel. Use this ID for <CHANNEL_ID> in the next step
   • Do a POST to /services/data/v37.0/sobjects/StreamingChannel/<CHANNEL_ID>/push with a payload of:
     • { "pushEvents": [{"payload": "first push"} ]}
3. Open the Visualforce Page by opening the Durable Streaming Demo app and clicking the Durable Generic Streaming Demo tab or by navigating to /apex/DurableGenericStreamingDemo. This Visualforce page will auto-subscribe to /u/TestStreaming using Durable Generic Streaming
   • This could fail if you haven't created the streaming channel and haven't pushed at least 1 event to that channel)
4. Generate new events using on-page controls.
   • You can also push new events through the REST API per the standard Generic Streaming documentation
   • Observe events being received in bottom panel.
5. Update replay subscription settings by changing the Replay From attribute. The replay option changes where your subscription starts in the event stream:
   • -2 replays from the earliest available event
   • -1 (or no ID) replays only new events
   • A specific Replay ID replays all events after that specific ID

Issues to Remember

1. You cannot replay using an ID outside of your event stream window (if you provide an ID from 2 weeks ago, it will be invalid)
2. The current event stream window is 24 hours