Apex Best Practices

✅ Apex Best Practices: Separation of Concerns & Modular Coding

Writing clean, scalable Apex code requires following key best practices such as Separation of Concerns (SoC) and Modular Coding. These help you build maintainable, testable, and reusable Salesforce applications.

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📌 What is Separation of Concerns?

Separation of Concerns means dividing code into distinct sections, each handling a specific responsibility. In Apex, this typically involves:

• 🔁 Keeping Triggers free of business logic
• 🧠 Moving logic to Handler and Helper classes
• 🔧 Using Utility classes for common logic

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📁 Recommended Structure

/triggers
  ContactTrigger.trigger

/classes
  ContactTriggerHandler.cls
  ContactHelper.cls
  ValidationUtils.cls

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🧩 Example: Good Modular Design

1️⃣ Trigger (Only Entry Point)

ContactTrigger.trigger

trigger ContactTrigger on Contact (before insert) {
    ContactTriggerHandler.handleBeforeInsert(Trigger.new);
}
  

2️⃣ Handler Class

ContactTriggerHandler.cls

public class ContactTriggerHandler {
    public static void handleBeforeInsert(List newContacts) {
        ContactHelper.setDefaultTitle(newContacts);
    }
}
  

3️⃣ Helper Class

ContactHelper.cls

public class ContactHelper {
    public static void setDefaultTitle(List contacts) {
        for(Contact c : contacts) {
            if(String.isBlank(c.Title)) {
                c.Title = 'Customer';
            }
        }
    }
}
  

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🔁 Comparison Table

Approach	Without SoC	With SoC (Best Practice)
Trigger	Contains all logic	Delegates to handler
Handler	Not used	Controls flow based on event
Helper	Logic mixed into trigger	Contains actual business logic

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🧪 Benefits of Modular Design

• ✅ Easier to test individual components
• ✅ Encourages code reuse
• ✅ Simplifies debugging and maintenance
• ✅ Enhances team collaboration

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📋 Final Best Practices

• Use TriggerHandler classes for all triggers
• Move logic to Helper and Service classes
• Use utility classes for reusable functions (e.g., validation, formatting)
• Keep classes focused on a single responsibility
• Use meaningful method and variable names