In OutSystems, how is mandatory field validation performed?

In OutSystems, mandatory field validation is typically handled through Built-in Validations on submit action. This feature allows developers to set rules for mandatory fields automatically, ensuring that the system checks for filled inputs when a user submits a form. The built-in validation mechanisms save time and effort by providing a straightforward way to enforce field requirements without the necessity to write custom code or define manual checks for each input field.

When using these built-in validations, the platform automatically applies this logic during the submission process, giving immediate feedback to the user if any required fields are left empty. This method is efficient as it leverages OutSystems' capabilities, enabling developers to focus on other aspects of the application while still ensuring data integrity through standard field validation practices.

Other options suggest alternative approaches to validation that either require more manual intervention or do not apply the efficiency of built-in mechanisms, but the built-in validation approach is the standard and preferred method in OutSystems applications for ensuring mandatory fields are properly validated.