com.whitestein.lsps.vaadin.forms.validation

Class ErrorMessageController

java.lang.Object

com.whitestein.lsps.vaadin.forms.validation.ErrorMessageController

All Implemented Interfaces:

Serializable

public class ErrorMessageController
extends Object
implements Serializable

This class controls the mapping of error messages of data constraint violations to the form components. If a custom handling of mapping of error messages to certain component is needed then this class should be extended and the methods mapConstraintViolation(ConstraintViolation, FormComponent) and clearErrorMessagesOnComponent(FormComponent) should be overridden.

Note: Subclasses of this class must be thread safe.

Author:

jsa

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected Form	form A form this controller controls error messages for.

Constructor Summary

Constructors

Constructor and Description
ErrorMessageController(Form form) Creates a new error message controller for the provided form.

Method Summary

Modifier and Type	Method and Description
protected void	addErrorMessage(String message, FormComponent component) Adds an error message to a component.
void	clearErrorMessages(FormComponent component) Clears error messages on the component and all it's descendants.
protected void	clearErrorMessagesOnComponent(FormComponent component) Clears all error messages on the given component.
void	displayErrorMessages(List<ConstraintViolation> constraintViolations, FormComponent root) Displays constraint violations error messages on the form components.
protected boolean	mapConstraintViolation(ConstraintViolation violation, FormComponent component) Checks whether the constraint violation error message should be displayed on the component and if yes then shows the error message on the component.

Methods inherited from class java.lang.Object

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

Field Detail

form

protected final Form form

A form this controller controls error messages for.

Constructor Detail

ErrorMessageController

public ErrorMessageController(Form form)

Creates a new error message controller for the provided form.

Parameters:

form - the form this controller should control error messages for.

Method Detail

displayErrorMessages

public void displayErrorMessages(List<ConstraintViolation> constraintViolations,
                                 FormComponent root)

Displays constraint violations error messages on the form components. This method tries to map the error messages to the components bound to record properties which are source of the constraint violations.

If subclasses need to override the mapping of a constraint violation to the specific component they should override the mapConstraintViolation(ConstraintViolation, FormComponent) method.

Parameters:

constraintViolations -

root - the component defining the root of the sub-component-tree where to start.

See Also:

mapConstraintViolation(ConstraintViolation, FormComponent)

mapConstraintViolation

protected boolean mapConstraintViolation(ConstraintViolation violation,
                                         FormComponent component)

Checks whether the constraint violation error message should be displayed on the component and if yes then shows the error message on the component. Subclasses may override this method if checking whether a constraint violation belongs to the component and displaying an error message requires some component specific actions but the following must be true:

1. The error message is not displayed on the component if calling forms::FormComponent.excludeConstraintViolation(violation) returns false for this constraint violation and calling forms::FormComponent.includeConstraintViolation(violation) returns false.
2. The error message is displayed on the component if calling forms::FormComponent.includeConstraintViolation(violation) returns true

The error message should be added to the component by calling addErrorMessage(String, FormComponent).

Parameters:

violation - the constraint violation to evaluate

component - the component which is a candidate for the error message

Returns:

true if the error message of the constraint violation has been added to the component; otherwise false

addErrorMessage

protected void addErrorMessage(String message,
                               FormComponent component)

Adds an error message to a component.

Parameters:

message - the message to add

component - the component

clearErrorMessages

public void clearErrorMessages(FormComponent component)

Clears error messages on the component and all it's descendants. If a component requires some specific action to clear error messages then subclasses rather then overriding this method should override clearErrorMessagesOnComponent(FormComponent) and peform the custom clearing there.

Parameters:

component - the component which specifies the root of the component sub-tree to walk through

See Also:

clearErrorMessagesOnComponent(FormComponent)

clearErrorMessagesOnComponent

protected void clearErrorMessagesOnComponent(FormComponent component)

Clears all error messages on the given component.

Parameters:

component - the component which should be cleared of the error messages