Question for confirmation: Callout from Trigger using Platform Events

Question

After a record is updated in Salesforce, i need to perform a callout to synchronize data to an External System.

Ideally, i would like to do this kind of synchronously, however it doesn't seem to be achievable. I read this document from Salesforce, where it is said that we can perform callouts after publishing Platform Event messages. However, there is a note saying: "This feature doesn't change the way you make Apex callouts from Apex triggers, which require the @future(callout=true) annotation."

My questions is more for confirmation: Is there a chance that in a Trigger i publish a platform event, and after the event is published to perform a callout to the external system? I suppose no, but i ask more for confirmation.

From my understanding, we should use @future methods, however it also needs handling concerning the Order of execution (update the record now and in 2 seconds - callouts could be performed in a different sequence, since they are asynchronous.

Answer 1

Platform Event Triggers also can't make callouts, so you'd still need a Future or Queueable method. Note that asynchronous methods are still called in order of being queued, so you don't really need to worry about the "ordering problem."

Answer 2

You can achieve this now with Platform Event Triggered flows.

Once you publish a platform event. You can configure and flow to listen to this and then from the Flow configure it to call an Apex Action.

NOTE : When consuming the params in the invocalble request DO NOT USE strings.get(0), as Platform events batches events raised in same time and then passes it to the Apex action. So we should iterate the input params here.

public without sharing class SendExternalAPIRequestPE {

    @InvocableMethod(Label='test callout' Callout=true)
    public static void fireAPIRequest(List<String> strings){
        Http h = new Http();
        HttpRequest req = new HttpRequest();
        req.setEndpoint('https://jsonplaceholder.typicode.com/users');
        req.setMethod('GET');
        HttpResponse res = new HttpResponse();
    }
}