How do you make a field an email field not required in Android Saripaar?

Question

I have a simple form in my Android app that I am using Android Saripaar to validate, one of the fields is an email address and according to the first example in the docs it should look something like this:

@NotEmpty
@Email
private EditText emailEditText;

However I would like it to be an optional field so I omitted the @NotEmpty annotation:

@Email
private EditText emailEditText;

But when I leave it empty it understandably marks it as an invalid email address. Is it possible to have this field be optional without writing a custom rule?

Answer 1

Since we needed an optional email field for a project I went ahead and made a rule/annotation combination according to this answer. Referred to Saripaar docs for Rules and Annotations.

OptionalEmailRule.java

public class OptionalEmailRule extends AnnotationRule<OptionalEmail, String> {

    protected OptionalEmailRule(final OptionalEmail email) {
        super(email);
    }

    @Override
    public boolean isValid(final String email) {
        if(TextUtils.isEmpty(email)){
            //email is empty and therefore valid
            return true;
        }
        else{
            //email is not empty, proceed as usual
            boolean allowLocal = mRuleAnnotation.allowLocal();
            return EmailValidator.getInstance(allowLocal).isValid(email);
        }

    }
}

OptionalEmail.Java

@ValidateUsing(OptionalEmailRule.class)
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
public @interface OptionalEmail {
    boolean allowLocal()    default false;

    int sequence()          default -1;
    int messageResId()      default -1;
    String message()        default "Invalid email";

}

Inside Validation Activity

1. Register the Annotation

   Validator.registerAnnotation(OptionalEmail.class);
   

2. Annotate the field

   @OptionalEmail
   public EditText editEmail;