net.sf.jguiraffe.gui.forms

Interface FormValidator

public interface FormValidator

Definition of an interface for objects that can validate forms.

While a normal validator can check only single fields of a form a FormValidator can deal with a form as a whole and thus can evaluate complex conditions and dependencies between the single elements.

This kind of validation takes places only after validation on both the field and form level have succeeded. Validations performed by FormValidator implementations are logically related to form level validations. The main difference is that a FormValidator can access all form fields at once and so is able to check relations between fields, too.

Validation of a form as a whole is very specific and strongly depends on the data fields contained in the form and its model. So there is no default base implementation of this interface. A concrete implementation can access the whole data that was entered into the form - either by querying the FieldHandler objects of the form or by calling the Form.readFields(Object) method passing in an appropriate data object - and perform arbitrary checks.

Version:

$Id: FormValidator.java 205 2012-01-29 18:29:57Z oheger $

Author:

Oliver Heger

Method Summary

Methods

Modifier and Type	Method and Description
FormValidatorResults	isValid(Form form) Validates the specified form.

Method Detail

isValid

FormValidatorResults isValid(Form form)

Validates the specified form. When this method is invoked by the form framework it is guaranteed that field and form level validation have passed. Thus all FieldHandler objects contained in the form have been initialized with the current data entered by the user. One way to obtain this data is by calling getData() on a FieldHandler. An alternative is to call readFields() on the Form object and let the data be copied into a corresponding model object. (This model object must of course be compatible with the BindingStrategy used by the Form.

Parameters:

form - the form object to be validated

Returns:

an object with validation results