Tuesday, 14 May 2019

Custom Notifications in Summer 19 Part 2 - Apex

Custom Notifications in Summer 19 Part 2 - Apex

Introduction

In Part 1 of this post I covered sending a custom notification from Process Builder when a record was created or edited with a specific attribute - a High Priority case to be exact. In this post I’ll cover sending a custom notification from Apex, although the notification is still actually sent from a Process Builder process, the logic around whether to send it lives in Apex.

To Code or Not to Code

The first question to ask yourself in these situations is do I actually need to go the Apex route. A process can send a notification when a record is created or edited to match a specific set of criteria, which coves a multitude of use cases. A couple of reasons why you might consider Apex are:

  • You want to send notifications for a large number of sObject typed and don’t want to create hundreds of processes. Not the greatest reason, but it would keep the process count down and thus remove some of the burden on your admins.
  • Separation of duties - if you are a developer and need a mechanism to send a notification without creating a new process, as you aren’t allowed to and the admins have a backlog of work. Again, not a great reason, as the governance is driving the solution, but this kind of thing does happen so we shouldn’t pretend it doesn’t.
  • When you want to send a notification only in specific circumstances, not every single time a record is created or edited. This is the most appropriate reason in my opinion - while you could create attributes to represent the circumstances in the record, you would be polluting your actual data with metadata to trigger functionality.

Platform Events

A process can be started in response to a number of things happening, but the one that can be used from Apex that isn’t changing a record is in response to a Platform Event. For the purposes of this post I’m reusing the Demo Event that I created for my Lightning Emp API in Winter 19 blog post.

Message sObject

In Part 1 of this post I mentioned in passing that the mechanism for generating notifications is better but not perfect, and this is a big reason why. As a process cannot use the payload of a platform event in decisions or actions, only as part of the entry criteria and choosing the record to use, I have to burn a custom object to hold details of the messages that I want to send. Not a huge deal, but it does add a certain clunkiness to the solution.

Custom Notification and Process Builder

As in Part 1, I need a custom notification type, Message in this case, to dovetail with the sObject name. I can then create a process builder that is started when a platform event is received and accesses a Message sObject whose ID is the platform event payload:

The notify action is trigged in all cases, as the logic is applied by Apex before the platform event is published, and sends a notification based on the contents of the associated Message record:

The Apex Code

Again from my my Lightning Emp API in Winter 19 post, I’m using the PlatformEventsDemo class to send the platform event after creating the Message record with details of the notification message and the user I want to send it to (there’s a link to the full solution at the end of this post):

Message__c message=new Message__c(Name='Demo Message',
                                  Message__c='Hello Bob!', 
                                  User__c='005B00000015moV');
insert message;
PlatformEventsDemo.PublishDemoEvent(message.Id);

Executing this code causes the red bell to display on the desktop and mobile, and the notification contains the message I sent:

Sharing is Caring

You can find the objects/events/code for this and the Part 1 post in my Summer 19 Samples repository.

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