org.omnifaces.taghandler

Class Validator

java.lang.Object

javax.faces.view.facelets.TagHandler

javax.faces.view.facelets.MetaTagHandler

javax.faces.view.facelets.DelegatingMetaTagHandler

javax.faces.view.facelets.FaceletsAttachedObjectHandler

javax.faces.view.facelets.ValidatorHandler

org.omnifaces.taghandler.Validator

All Implemented Interfaces:

AttachedObjectHandler, EditableValueHolderAttachedObjectHandler, FaceletHandler, ValueHolderAttachedObjectHandler

public class Validator
extends ValidatorHandler

The <o:validator> is a taghandler that extends the standard <f:validator> tag family with support for deferred value expressions in all attributes. In other words, the validator attributes are not evaluated anymore on a per view build time basis, but just on every access like as with UI components and bean properties. This has among others the advantage that they can be evaluated on a per-iteration basis inside an iterating component, and that they can be set on a custom validator without needing to explicitly register it in a tagfile.

Usage

When you specify for example the standard <f:validateLongRange> by validatorId="javax.faces.LongRange", then you'll be able to use all its attributes such as minimum and maximum as per its documentation, but then with the possibility to supply deferred value expressions.

 <o:validator validatorId="javax.faces.LongRange" minimum="#{item.minimum}" maximum="#{item.maximum}" />
 

The validator ID of all standard JSF validators can be found in their javadocs. First go to the javadoc of the class of interest, then go to VALIDATOR_ID in its field summary and finally click the Constant Field Values link to see the value.

It is also possible to specify the validator message on a per-validator basis using the message attribute. Any "{0}" placeholder in the message will be substituted with the label of the referenced input component. Note that this attribute is ignored when the parent component has already validatorMessage specified.

 <o:validator validatorId="javax.faces.LongRange" minimum="#{item.minimum}" maximum="#{item.maximum}"
     message="Please enter between #{item.minimum} and #{item.maximum} characters" />
 

JSF 2.3 compatibility

The <o:validator> is currently not compatible with validators which are managed via JSF 2.3's new managed=true attribute set on the FacesValidator annotation, at least not when using Mojarra. Internally, the converters are wrapped in another instance which doesn't have the needed setter methods specified. In order to get them to work with <o:validator>, the managed=true attribute needs to be removed, so that OmniFaces ValidatorManager will automatically manage them.

Author:

Bauke Scholtz

See Also:

DeferredTagHandlerHelper

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	Validator.DeferredValidator So that we can have a serializable validator.

Field Summary

Fields inherited from class javax.faces.view.facelets.DelegatingMetaTagHandler

delegateFactory

Fields inherited from class javax.faces.view.facelets.TagHandler

nextHandler, tag, tagId

Constructor Summary

Constructors

Constructor and Description
Validator(ValidatorConfig config) The constructor.

Method Summary

Modifier and Type	Method and Description
void	apply(FaceletContext context, UIComponent parent) Create a Validator based on the binding and/or validatorId attributes as per the standard JSF <f:validator> implementation and collect the render time attributes.
TagAttribute	getTagAttribute(String name) Just return TagHandler#getAttribute() via a public method (it's by default protected and otherwise thus unavailable inside collectDeferredAttributes().
protected TagHandlerDelegate	getTagHandlerDelegate()
boolean	isDisabled(FaceletContext context)

Methods inherited from class javax.faces.view.facelets.ValidatorHandler

getValidatorConfig, getValidatorId

Methods inherited from class javax.faces.view.facelets.FaceletsAttachedObjectHandler

applyAttachedObject, getAttachedObjectHandlerHelper, getFor

Methods inherited from class javax.faces.view.facelets.DelegatingMetaTagHandler

applyNextHandler, createMetaRuleset, getBinding, getTag, getTagId, setAttributes

Methods inherited from class javax.faces.view.facelets.TagHandler

getAttribute, getRequiredAttribute, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.faces.view.AttachedObjectHandler

applyAttachedObject, getFor

Constructor Detail

Validator

public Validator(ValidatorConfig config)

The constructor.

Parameters:

config - The validator config.

Method Detail

apply

public void apply(FaceletContext context,
                  UIComponent parent)
           throws IOException

Create a Validator based on the binding and/or validatorId attributes as per the standard JSF <f:validator> implementation and collect the render time attributes. Then create an anonymous Validator implementation which wraps the created Validator and delegates the methods to it after setting the render time attributes only and only if the disabled attribute evaluates true for the current request. Finally set the anonymous implementation on the parent component.

Specified by:

apply in interface FaceletHandler

Overrides:

apply in class DelegatingMetaTagHandler

Parameters:

context - The involved facelet context.

parent - The parent component to add the Validator to.

Throws:

IOException - If something fails at I/O level.

getTagAttribute

public TagAttribute getTagAttribute(String name)

Just return TagHandler#getAttribute() via a public method (it's by default protected and otherwise thus unavailable inside collectDeferredAttributes().

Overrides:

getTagAttribute in class DelegatingMetaTagHandler

Parameters:

name - The attribute name.

Returns:

The tag attribute associated with given attribute name.

getTagHandlerDelegate

protected TagHandlerDelegate getTagHandlerDelegate()

Overrides:

getTagHandlerDelegate in class ValidatorHandler

isDisabled

public boolean isDisabled(FaceletContext context)

Overrides:

isDisabled in class DelegatingMetaTagHandler