1.
Piggybacking Platform Events
or “How we crack nuts with the Great
Seal of England”
by Igor Chtivelband
!1

2.
#CD19
B.Sc. in Information Systems
Engineering
Double M.Sc. in Software
Engineering
Certified System and Application
Architect
VP Data at
!2

3.
#CD19
Event-driven architecture basics
!3

4.
#CD19
- First introduced in November 2017
- One can define a new Platform Event similarly to the way it is done with
Custom Objects
- Platform Events can be published using Apex, Declarative Tools (Process
Builder/Flow) and API
- Platform Events can be subscribed to using Apex Triggers, Process
Builders and CometD
Platform Events in Salesforce
!4

5.
#CD19
- Mainly we love them, because Platform Events help us to overcome
transaction limits
- We use them to inform Admins in case of exceptions/issues
(MessageForAdmin__e)
- We dispatch thousands of emails (some of them with custom
attachments) in a couple of clicks (ContactOrLeadEmailRequest__e)
- In case that a record is currently locked, we can update it asynchronously
using a custom Platform Event
So how exactly do we piggyback Platform Events in Billie?
!5

6.
#CD19
MessageForAdmin__e: Event Definition
!6

7.
#CD19
catch (Exception e){
MessageForAdmin__e m = new MessageForAdmin__e ();
m.Subject__c = 'Bad news: tried to send email, but could not find Attachment';
m.Body__c = e.getMessage();
EventBus.publish(m);
}
MessageForAdmin__e: Publishing
!7

8.
#CD19
- Easy to send a notification from Apex code/process
- Even if the main transaction is rolled-back, admins will still be notified
- Since event publishing is decoupled from event consumption, we can
always change the way the notifications are delivered (email, Slack, etc.)
MessageForAdmin__e: advantages
!8

9.
#CD19
ContactOrLeadEmailRequest__e: Definition
!9

10.
#CD19
String ATTACHMENT_NAME_TEMPLATE = '2019-02-%_Billie_Invoice.pdf';
String EMAIL_TEMPLATE = 'Contact_Monthly_FeeInvoice';
List<ContactOrLeadEmailRequest__e> events = new List<ContactOrLeadEmailRequest__e>();
for (Attachment att: [SELECT parentId,Name FROM Attachment WHERE Name like :ATTACHMENT_NAME_TEMPLATE]){
events.add(
new ContactOrLeadEmailRequest__e
(
ObjectID__c = att.parentId,
EmailTemplateName__c = EMAIL_TEMPLATE,
AttachmentNamePattern__c = att.Name
)
);
}
List<Database.SaveResult> results = EventBus.publish(events);
ContactOrLeadEmailRequest__e: Publishing
!10

11.
#CD19
- Limit of 100 emails per transaction is worked around
- We can send mass emails with individual attachments (currently not
supported by Salesforce “out of the box”)
- No need to configure Email Alert
- Email Messages are stored in Salesforce database and can be used for
later analysis
ContactOrLeadEmailRequest__e: advantages
!11

12.
#CD19
- Each EventBus.publish method call is considered a DML statement, and DML limits
apply
- Each EventBus.publish method call is considered an API call
- If you are trying to publish Platform Events from an external system, you have to
perform Oauth authentication
- It is impossible to replay Platform Events from Apex
- You can’t call Messaging.SingleEmailMessage methods directly in your event trigger
Considerations for Publishing and Subscribing to Platform Events
!12

13.
Thank you!
!13