Is it possible to write Trigger for Before & After DML?

Question

I'm wondering if I can write the trigger on Case, that works before and after DML in one file? I have two triggers on Case - first with method working on records before insert, and second for records after insert/update to make relationship.

I know that having two different triggers on the same object isn't a good practisce, so I'm trying now to make one trigger and have order in my code.

What do you think about this? Do you have similar situation in your dev career?

Best regards!

Answer 1

It is quite possible, and in fact recommended (if you need trigger logic on both events).

See also:

• Trigger Frameworks and Apex Trigger Best Practices
• Triggers (Apex Developer Guide)

A common pattern is to have three separate layers of code: the trigger itself, a handler, and a service layer. Here's the trigger framework I prefer.

Trigger

trigger CaseTrigger on Case (after insert)
{
    EventTriggerHandler handle = new EventTriggerHandler(trigger.new, trigger.oldMap);

    if (trigger.isBefore)
    {
        if (trigger.isInsert) handle.beforeInsert();
        if (trigger.isUpdate) handle.beforeUpdate();
        // etc
    }
    if (trigger.isAfter)
    {
        if (trigger.isInsert) handle.afterInsert();
        if (trigger.isUpdate) handle.afterUpdate();
        // etc
    }
}

Handler

public with sharing class EventTriggerHandler
{
    @TestVisible static Boolean bypassTrigger = false;

    final List<Event> newRecords;
    final Map<Id, Event> oldMap;
    public EventTriggerHandler(List<Event> newRecords, Map<Id, Event> oldMap)
    {
        this.newRecords = newRecords;
        this.oldMap = oldMap;
    }

    public void beforeInsert()
    {
        if (bypassTrigger) return;

        CaseService.doStuff1();
    }
    public void afterInsert()
    {
        if (bypassTrigger) return;

        CaseService.doStuff2();
    }

    public void beforeUpdate()
    {
        if (bypassTrigger) return;

        CaseService.doStuff1();
    }
    public void afterUpdate()
    {
        if (bypassTrigger) return;

        CaseService.doStuff3();
    }
}

Service

public with sharing class CaseService
{
    public static void doStuff1() { /* "how" implementation */ }
    public static void doStuff2() { /* "how" implementation */ }
    public static void doStuff3() { /* "how" implementation */ }
}