Best Practices for Apex Trigger in Salesforce

 

1. Follow the One Trigger Per Object Principle

• Create a single trigger per object to centralize logic and avoid conflicts.
• Use a handler class to process the logic, separating the trigger's definition from its implementation.

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2. Use Context Variables

• Use context variables like Trigger.isInsert, Trigger.isUpdate, Trigger.isDelete, etc., to identify the context of the trigger execution.
• This makes your code modular and avoids redundancy.

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3. Bulkify Your Code

• Always assume that triggers will handle multiple records (bulk operations).
• Use collections like List, Set, or Map instead of working with a single record.

Example:

apex

List<Account> accountsToUpdate = new List<Account>();
for (Account acc : Trigger.new) {
    if (acc.Industry == 'Technology') {
        acc.Rating = 'Hot';
        accountsToUpdate.add(acc);
    }
}
update accountsToUpdate;

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4. Avoid SOQL and DML in Loops

• Perform SOQL (Salesforce Object Query Language) queries and DML (Data Manipulation Language) operations outside loops to avoid hitting governor limits.

Bad Practice:

apex

for (Contact con : Trigger.new) {
    Account acc = [SELECT Name FROM Account WHERE Id = :con.AccountId];
    acc.Description = 'Updated by Trigger';
    update acc;
}

Good Practice:

apex

Set<Id> accountIds = new Set<Id>();
for (Contact con : Trigger.new) {
    accountIds.add(con.AccountId);
}

Map<Id, Account> accountMap = new Map<Id, Account>(
    [SELECT Id, Name FROM Account WHERE Id IN :accountIds]
);

List<Account> accountsToUpdate = new List<Account>();
for (Contact con : Trigger.new) {
    if (accountMap.containsKey(con.AccountId)) {
        Account acc = accountMap.get(con.AccountId);
        acc.Description = 'Updated by Trigger';
        accountsToUpdate.add(acc);
    }
}

update accountsToUpdate;

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5. Handle Exceptions Gracefully

• Use try-catch blocks to handle exceptions and log errors using custom objects or the System.debug() method.

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6. Ensure Trigger Recursion is Controlled

• Prevent recursive trigger execution by using static variables.

Example:

apex

public class TriggerHandler {
    public static Boolean isExecuting = false;
}

In Trigger:

apex

if (!TriggerHandler.isExecuting) {
    TriggerHandler.isExecuting = true;
    // Trigger logic here
    TriggerHandler.isExecuting = false;
}

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7. Write Comprehensive Test Classes

• Achieve 100% code coverage by testing all possible scenarios, including bulk, single, positive, and negative cases.
• Use Test.startTest() and Test.stopTest() to validate limits and asynchronous behavior.

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8. Minimize Hard-Coding

• Use Custom Settings, Custom Metadata, or Label records instead of hard-coded values.

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9. Follow Naming Conventions

• Use clear and descriptive names for triggers and handler methods (e.g., AccountTrigger and AccountTriggerHandler).

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10. Maintain a Trigger Framework

• Implement a trigger framework to standardize your approach. Popular frameworks include the TDTM (Trigger Handler Framework) and SObject Framework.

Example Structure:

apex

trigger AccountTrigger on Account (before insert, before update) {
    AccountTriggerHandler handler = new AccountTriggerHandler();
    if (Trigger.isBefore) {
        if (Trigger.isInsert) {
            handler.beforeInsert(Trigger.new);
        } else if (Trigger.isUpdate) {
            handler.beforeUpdate(Trigger.new);
        }
    }
}

Handler Class Example:

apex

public class AccountTriggerHandler {
    public void beforeInsert(List<Account> newRecords) {
        // Logic here
    }

    public void beforeUpdate(List<Account> newRecords) {
        // Logic here
    }
}

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11. Test and Optimize Performance

• Use Salesforce's debug logs to monitor trigger execution and optimize queries, loops, and DML operations for better performance.