How to validate blank fields?

[notramo]

When a form field is optional, and the user do not fill it, the form still contains the field but it's an empty string. If the model has required: false but blank: false, then its rejected.
Is there some option to convert '' to Nil during validation?

[ellmetha]

Why set blank: false on your model if the corresponding field in the schema is optional? Your model field should have blank: true set in order to make this validation work as expected since it appears to be optional.

[notramo]

As I explained in #177 (comment), the documentation was confusing, I dit not know it applies to nil also.