org.apache.tapestry5.validator
Class Required

java.lang.Object
  org.apache.tapestry5.validator.AbstractValidator<Void,Object>
      org.apache.tapestry5.validator.Required

All Implemented Interfaces:

Validator<Void,Object>

public final class Required
extends AbstractValidator<Void,Object>

A validator that enforces that the value is not null and not the empty string. This validator is not configurable.

Constructor Summary

Required()

Method Summary

boolean	isRequired() The exception to the rule.
void	render(Field field, Void 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)).
void	validate(Field field, Void constraintValue, MessageFormatter formatter, Object value) 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).

Methods inherited from class org.apache.tapestry5.validator.AbstractValidator

getConstraintType, getMessageKey, getValueType

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Required

public Required()

Method Detail

validate

public void validate(Field field,
                     Void constraintValue,
                     MessageFormatter formatter,
                     Object value)
              throws ValidationException

Description copied from interface: Validator

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.

Parameters:

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

Throws:

ValidationException - if the value violates the constraint

isRequired

public boolean isRequired()

The exception to the rule.

Specified by:

isRequired in interface Validator<Void,Object>

Overrides:

isRequired in class AbstractValidator<Void,Object>

render

public void render(Field field,
                   Void constraintValue,
                   MessageFormatter formatter,
                   MarkupWriter writer,
                   FormSupport formSupport)

Description copied from interface: Validator

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)).

Parameters:

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