Salesforce Platform Developer Practice Exam

To ensure that user input in the Visualforce page is validated, which approach should the developer take?

1. Implement error handling in the Visualforce page itself.

2. Use JavaScript to validate before submission.

3. Use a controller to manage data validation logic.

4. Implement custom validation rules in Salesforce.

The correct answer is: Use a controller to manage data validation logic.

Utilizing a controller to manage data validation logic is a solid approach, as it allows developers to encapsulate the validation rules clearly and maintain a clean separation between the presentation layer (Visualforce page) and the business logic. By leveraging a custom controller or controller extension, the developer can implement comprehensive validation logic that checks the input data according to specific requirements before it is processed or saved. Controllers can utilize standard or custom validation to ensure the integrity of the data being entered by users. This method not only adheres to best practices of the MVC (Model-View-Controller) architecture but also allows for easier unit testing and reuse of validation logic across multiple Visualforce pages. While other methods may provide some level of validation, they often lack the robustness and maintainability found in a well-structured controller approach. For instance, implementing error handling directly in the Visualforce page may lead to scattered logic and challenges in managing complex rules essentially, leading to a more difficult maintenance process. On the other hand, using JavaScript for front-end validation is beneficial in enhancing user experience through immediate feedback, but it is not sufficient on its own. JavaScript can be bypassed, so server-side validation is necessary for security and data integrity. Creating custom validation rules in Salesforce provides