Salesforce Best Practice: Using Domain Classes

In Salesforce development, using Domain classes is a powerful way to organize and encapsulate business logic within your application. Domain classes allow you to centralize object-related logic, ensuring your code is clean, scalable, and easier to maintain. In this post, we’ll cover the best practices for using Domain classes in Salesforce and how they can help streamline your development process.

What Are Domain Classes in Salesforce?

Domain classes in Salesforce are designed to encapsulate the business logic related to specific Salesforce objects. Instead of spreading logic across various triggers, service layers, and controllers, Domain classes help concentrate that logic in one place, making it easier to maintain and extend as business requirements evolve.

Benefits of Using Domain Classes:

• Centralized Logic: Domain classes store business logic related to objects in one location.

• Improved Maintainability: Keeping logic centralized makes it easier to update and manage code.

• Consistency: Domain classes ensure business rules are applied consistently, no matter how the object is accessed.

Best Practices for Using Domain Classes

1. Centralize Business Logic

The core principle behind Domain classes is the centralization of business logic. Rather than scattering logic across multiple layers of your application, use Domain classes to encapsulate any object-specific logic like validations, calculations, or actions. This approach not only makes it easier to update logic but also ensures consistency in how objects are handled.

Example:

2. Use Domain Classes in Triggers

One of the most common applications of Domain classes is within triggers. Instead of writing complex logic directly in your trigger, delegate the operations to a Domain class. This keeps triggers lightweight and ensures that business logic is reusable across different contexts.

Example:

3. Separate Read and Write Logic

Domain classes should primarily focus on write logic (DML operations like inserts, updates, and deletes). For read operations (SOQL queries), it's better to separate the responsibilities using Selector classes. This division keeps your Domain classes clean and focused on object manipulation.

4. Use Dependency Injection for Flexibility

To make Domain classes even more modular and testable, leverage Dependency Injection by passing services or utilities into the Domain class rather than hardcoding dependencies. This makes your Domain class easier to test and modify without altering its core logic.

Example:

5. Write Unit Tests for Domain Classes

Since Domain classes encapsulate critical business logic, it’s essential to write thorough unit tests to ensure that the logic behaves as expected. By decoupling logic from triggers and controllers, Domain classes make it easier to write isolated and maintainable tests.

Conclusion

Using Domain classes in Salesforce is a best practice for ensuring your business logic is encapsulated, maintainable, and scalable. By centralizing logic, separating concerns, and applying Dependency Injection, Domain classes can streamline your Salesforce development while promoting cleaner code architecture.

FAQs

1. What is a Domain class in Salesforce? A Domain class is used to encapsulate business logic related to Salesforce objects, ensuring that the logic is centralized, maintainable, and scalable.
2. How do Domain classes improve maintainability? Domain classes keep business logic in one place, making it easier to update and manage without needing to modify multiple parts of your codebase.
3. Can I use Domain classes in triggers? Yes, Domain classes are commonly used to handle business logic within triggers, keeping triggers lightweight and clean.
4. Should Domain classes handle SOQL queries? Domain classes should focus on write operations (insert, update, delete). Read operations (SOQL queries) are best handled by Selector classes.
5. How do I unit test a Domain class? You can unit test Domain classes by creating test instances of the objects they manipulate and validating that the class logic behaves as expected.