Interface Validator<C,​T>

    • Method Detail

      • getConstraintType

        Returns the type of constraint value used with this validator. Constraint values are used to parameterize a validator, for example a "maxLength" validator will have a constraint value of type int (the maximum length allowed). For constraints that do not have a constraint value, this method returns null.
      • validate

        void validate​(Field field,
                      C constraintValue,
                      MessageFormatter formatter,
                      T value)
               throws ValidationException
        Invoked after the client-submitted value has been translated to check that the value conforms to expectations (often, in terms of minimum or maximum value). If and only if the value is approved by all Validators is the value applied by the field.
        field - the field for which a client submitted value is being validated
        constraintValue - the value used to constrain
        formatter - Validation messages, in the appropriate locale
        value - the translated value supplied by the user
        ValidationException - if the value violates the constraint
      • isRequired

        boolean isRequired()
        Returns true if the validator should be invoked for null or blank (empty string) values. This is generally false, but is true for validators that enforce that a non-blank value is required. This is the basis of the Field.isRequired() property.
      • render

        void render​(Field field,
                    C constraintValue,
                    MessageFormatter formatter,
                    MarkupWriter writer,
                    FormSupport formSupport)
        Hook used by components to allow the validator to contribute additional attributes or (more often) client-side JavaScript (via the FormSupport.addValidation(Field, String, String, Object)).
        field - the field which is currently being rendered
        constraintValue - the value used to constrain input
        formatter - validation message, in the appropriate locale
        writer - markup writer, allowing additional attributes to be written into the active element
        formSupport - used to add JavaScript