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![API Published Events
● External applications use an
API to publish event
messages.
● You can use any Salesforce
API to create events in same
way as you would insert
sObjects.
● To publish multiple event
messages use the
composite resource.
REST endpoint:
/services/data/v47.0/sobjects/Registration_Notification__e
Request body:
{
"CaseId__c":"5008A000006GvpKQAS"
}
REST response:
{
"id" : "e01xx0000000001AAA",
"success" : true,
"errors" : [ {
"statusCode" : "OPERATION_ENQUEUED",
"message" : "154dba26-db92-4557-ad6b-9c7222428346",
"fields" : [ ]
} ]
}](https://image.slidesharecdn.com/platformevents-210415231706/85/Platform-Events-by-Tim-Taylor-7-320.jpg)
Uploaded byChristine Smith
Platform Events by Tim Taylor
This document explains Salesforce's event-driven software architecture, including the components of platform events and how they can be published and subscribed to by various means, such as Apex code and Salesforce APIs. It discusses the process of creating custom platform events, publishing them, and the auto subscription mechanism available through Apex triggers and other tools. Additionally, it outlines a business case for integrating Salesforce with Jira for registration notifications and automating customer communications.
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Platform Events by Tim Taylor
- 1. Platform Events Salesforce’s Event-DrivenSoftware Architecture timdt01@gmail.com Tim Taylor, Jacksonville Developer Group member.
- 2. What is anEvent-Driven Software Architecture? Event-Driven Software Architecture ● Consists of event producers, event consumers, and channels. ● Suitable for large distributed systems ● Decouples event producers from the event consumers. ● Components: ● Event: change in state meaningful to business ● Event Message: data about the event ● Producer: publisher of the event message over channel ● Channel: conduit to transmit the event ● Consumer: subscribes to a channel to receive event.
- 3. Custom Platform Events ●Platform events are messages that are published and subscribed to. ● One or more subscribers can listen to the same event and carry out independent actions. ● This way, key components of an integration are decoupled. ● Define a custom event in same way as custom objects. ● Create the event by giving it a name and adding custom fields.
- 4. Publishing Platform Events ●You can publish platform events by: ● Apex code. ● Point and click tools such as Process Builder and Flow Builder. ● Any Salesforce API from external applications. ● SOAP, REST or Bulk API Platform Event External App Salesforce Trigger REST API APEX
- 5. Apex Published Events ●To publish event messages by Apex, call the EventBus.publish() method passing an instance of the custom event.
- 6. Process Builder PublishedEvents ● Add a Create a Record action. ● For the Record Type, select the custom platform event. ● Populate the fields of the platform event.
- 7. API Published Events ●External applications use an API to publish event messages. ● You can use any Salesforce API to create events in same way as you would insert sObjects. ● To publish multiple event messages use the composite resource. REST endpoint: /services/data/v47.0/sobjects/Registration_Notification__e Request body: { "CaseId__c":"5008A000006GvpKQAS" } REST response: { "id" : "e01xx0000000001AAA", "success" : true, "errors" : [ { "statusCode" : "OPERATION_ENQUEUED", "message" : "154dba26-db92-4557-ad6b-9c7222428346", "fields" : [ ] } ] }
- 8. Subscribing to PlatformEvents ● You can subscribe to platform events by: ● Apex Triggers. ● Point and click tools such as Process Builder and Flow Builder. ● Lightning apps can subscribe through the empApi component. ● Through CometD in external apps. Platform Event CometD Apex Trigger Process/Flow
- 9. Subscribing to Eventswith Apex Triggers ● Triggers provide an auto subscription mechanism in Apex. No need to explicitly create and listen to a channel. ● Platform events ONLY support after insert triggers.
- 10. Subscribing to Eventswith Processes ● Processes also provide an auto subscription mechanism for published events. No need to explicitly create and listen to a channel. ● To subscribe to a platform event, build the process to start when it receives an event message. ● Then associate the process with a platform event and an object
- 11. Subscribing to Eventswith Lightning Components ● Subscribe to platform events with empApi component ● In Lightning Web components import the methods from the lightning/empApi module and then call the imported methods from your javascript code. ● In Aura components add the lightning:empApi component in your markup and then add functions to call the component methods in your client- side controller. Lightning Web Component: Import { subscribe, unsubscribe, onError, } from ‘lightning/empApi’; Lightning Aura Component: <lightning:empApi aura:id=“empApi” />
- 12. Subscribing to Eventswith CometD ● External systems can subscribe to platform events using CometD ● The entities that consume platform events should subscribe to the event’s channel. The platform event for our example: /event/Registration_Notification__e Event message when received: { "data": { "schema":"dffQ2QLzDNHqwB8_sHMxdA", "payload": { "CreatedDate": "2020-03-09T18:31:40.517Z", "CreatedById": "005D0000001cSZs", "CaseId__c":"5008A000006GvpKQAS" }, "event": { "replayId": 1 } }, "channel": "/event/Registration_Notification__e“ }
- 13. Automatic Retry CapabilitiesWhen Errors Occur ● Helpful to retry consuming an event when a transient error occurs. ● This is only available with event triggers. ● Retry events by throwing the EventBus.RetryableException.
- 14. Resuming a PlatformEvent ● If a trigger stops execution intentionally or because of unhandled exception ● Set a checkpoint to resume by setting replay ID of last successful event message. ● EventBus.TriggerContext.currentContext().setResumeCheckpoint(event.replayId)
- 15. Business Need –Organization Registration Notification Salesforce is integrated with JIRA to allow for synchronization of JIRA tickets with the corresponding Salesforce cases. Organizations register with Availity daily. Some of those registrations are flagged for follow up for additional information and a JIRA ticket is created along with a corresponding Salesforce case. Our Fraud Analysts, working in JIRA, identify the necessary information needed and apply a series of labels to the JIRA ticket and update the ticket status to Awaiting Reply. The Salesforce case is automatically updated with this information. The client support organization then manually reviews those labels and sends an email to the customer by concatenating a series of Lightning Email Templates that correspond to the labels assigned to the case. There are dozens of these registrations daily that often pile up for processing. The Goal is to remove the manual process of sending the notifications to customers.
- 16. Apex Class Solution –Organization Registration Notification Platform Event Process Publishes Event JIRA Ticket Salesforce Case Apex Trigger REST API Trigger Subscribes to Event
- 17. “DEMO TIME!” hope itworks!
- 18. What’s Next? How canI learn more about Platform Events? Platform Events Developer Guide https://developer.salesforce.com/docs/atlas.en-us.platform_events.meta/platform_events/platform_events_intro.htm Platform Events Basics https://trailhead.salesforce.com/en/content/learn/modules/platform_events_basics
Editor's Notes
- #3 In 2017 Salesforce introduced platform events to support the Event-Driven software architecture Prior to this integrating distributed systems required tightly coupled point to point integrations such as the request response REST API integrations. Systems in request-response communication models make a request to a web service. In comparison, systems in an event-driven architecture react to an event in near real time when the event occurs. Event producers don’t know the consumers that receive the events. Any number of consumers can receive and react to the same events. The only dependency between producers and consumers is the semantic of the message content. Example: eCommerce system publishes a single event that is consumed by several services to handle (payment processing, shipping, inventory updates, …).
- #4 Event similar to sObject -> Event message similar to how a record is an instance of a sObject. Note the API name suffix of __e instead of __c Published events cannot be edited/deleted. To consume the event, an app can subscribe to it (as opposed to querying it). Custom fields become the content or semantics of the event message. Publish Behavior: Publish After Commit. When subscriber dependent on data to be present or if you simply don’t want an event to publish if transaction fails. Publish Immediately. Without fear of rollback. This is especially convenient for logging purposes so that you don’t have to relay on debug logs.
- #6 Not following best practices here for brevity In this example I want to publish the event when the case JIRA Status is changed to Awaiting Reply Populating and instantiating the same platform event we saw earlier. EventBus.publish() method pushes the message to the channel. Behavior is similar to Database.insert() where you can interrogate the Database.SaveResult. Apex governor limits apply. Each EvenBus.publish execution counts as a DML statement. You can also capture the Database.SaveResult object to determine whether the operation was successful or not in same fashion as you would insert or update sObjects.
- #7 For Flows, add a Create Records element to the appropriate flow. Where you'd usually pick an object to create, select the custom platform event.
- #8 Such as SOAP API, REST API, or Bulk API. POST request to the endpoint Request body will contain a JSON formatted message containing values for any of the fields defined for the event.
- #9 We’ll look at some examples of subscribing by trigger and process and talk a little about the lightning components BUT we won’t explicitly go over CometD
- #10 Not following best practices here for brevity Very similar to trigger for any sObject The after insert trigger event corresponds to the time after a platform event is published Along with processes, it is the most straight forward method of consuming published events Trigger Batch size: The Apex trigger batch size for platform events is 2,000 as opposed to trigger batch size of 200 for standard/custom objects.
- #11 Build the process to start when it receives a platform event message. In the process’s trigger, associate the process with a platform event and an object. The object you choose determines with object fields you can access throughout your process. The process looks for a case record whose Id matches the case id in the event message. Flow Builder subscribes to events by using a Pause element instead of starting of flow when a platform event occurs. When the event is receives the flow resumes.
- #12 Using empApi component is slightly different for Lightning Web Components versus Aura Components but both involve defining the empApi component and utilizing the empApi components methods of subscribe, unsubscribe, etc.
- #13 Visualforce pages can use CometD as well. CometD is a scalable WebSocket and HTTP based event and message routing bus. CometD is a set of library to write web applications that perform messaging over the web. The replay ID is a system generated value, and it is used to position the event in the event stream.
- #14 Great for situations where the error is likely to go away later. Could be timeouts, row locks. Or as simple as a field value change. Events are resent after a small delay that increases in subsequent retries. Retrying the event causes all events in the batch to be resent. May retry events 9 times (the initial run plus 9 retries). Make sure to retry LESS THAN 9 times. After the ninth retry, the trigger moves to an error state and must then be fixed and saved.
- #15 Unhandled exceptions such as CPU or heap size limits. Intentionally designing trigger batch size limits or some other processing logic. Because trigger batch sizes can be 2000 instead of normal 200, you can reach some limits more readily. New batch starts with event message after the one with replay ID you set.
- #17 Lightning Email Templates are not available for use in Email Alerts, so basic Process Builder or Workflow Rules are not an option. Additionally, there are dozens of these labels with the corresponding email templates which complicates the logic needed to implement with Process Builder or Workflow Rule. Since the label values match the email template names, I can query the needed email templates through Apex and send the notification to the customer.