Trigger Recursion Control

One of the common problems in Apex triggers is accidental recursion. That happens when a trigger causes an update, and the same trigger runs again.

Why recursion is bad

Uncontrolled recursion can lead to infinite loops, repeated DML operations, and hitting governor limits. The safe fix is to add a guard so each trigger only runs once per transaction.

Use a static helper variable

Static variables keep state for the transaction, so you can detect whether your trigger already ran. 


public class OpportunityTriggerHelper {
    public static Boolean hasRun = false;
}

trigger OpportunityTrigger on Opportunity (before update) {
    if (OpportunityTriggerHelper.hasRun) {
        return;
    }

    OpportunityTriggerHelper.hasRun = true;

    for (Opportunity opp : Trigger.new) {
        if (opp.StageName == 'Closed Won') {
            opp.Description = 'Closed this deal';
        }
    }
}

Better: use a reusable guard method

A small helper class makes recursion control easier to reuse across multiple triggers. 


public class TriggerExecutionGuard {
    private static Set executedTriggers = new Set();

    public static Boolean canRun(String triggerName) {
        if (executedTriggers.contains(triggerName)) {
            return false;
        }
        executedTriggers.add(triggerName);
        return true;
    }
}

trigger AccountTrigger on Account (before update) {
    if (!TriggerExecutionGuard.canRun('AccountTrigger')) {
        return;
    }

    // trigger logic here
}

When you still need recursive updates

Sometimes a trigger must update a related record, and that related record has its own trigger. In those cases, design the triggers so they can safely run multiple times without repeating work.

Key rule

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