Field Validation on the frontend

[Khizar-Hussian]

On Primero 2.0 all the front end form fields are validated in the back end, after the save button is pressed and then the feedback/errors are populated at the bottom of the form. When the user has edited multiple forms, this poses an issue, as the errors for the prior forms get aggregated after validation, and get displayed at the bottom of the form the user is currently editing.

This problem can be alleviated by adding validation to some of the front-end fields. For instance, child's age bracket validation can be done on spot, it shouldn't have to be sent to the back-end for validation.

We would like to know if this is possible on V2, if so, what is the recommended method for adding those field validations, and where do we add them. Another thing we would like to know is how can we make the errors pop up immediately while the user is still in the relevant form. We would like to make these changes forward compatible as to not break the functionality when we inevitably migrate to a newer version, say 2.3.