Chapter 8. Validation

⁠Chapter 8. Validation

JavaServer Faces 2 provides built-in support for bean validation as per the Java Specification Request JSR-303 standard. As such, containers must validate model objects. Validation is performed at different application tiers according to annotation-based constraints. Refer to http://jcp.org/en/jsr/detail?id=303 for further details on the JSR-303 specification.

Example 8.1, “JSR-303 validation annotations” shows an example JSF managed bean. The bean includes JSR-303 annotations for validation. Validation annotations defined in this way are registered on components bound to the bean properties, and validation is triggered in the Process Validation phase.

⁠

Example 8.1. JSR-303 validation annotations

import javax.validation.constraints.Max;
import javax.validation.constraints.Min;
import javax.validation.constraints.Pattern;
import javax.validation.constraints.Size;

@ManagedBean
@RequestScoped
public class UserBean {

   @Size(min=3, max=12)
   private String name = null;
   
   @Pattern(regexp = "^[\\w\\-]([\\.\\w])+[\\w]+@([\\w\\-]+\\.)+[a-zA-Z]{2,4}$" , message="Bad email")
   private String email = null;
   
   @Min(value = 18)
   @Max(value = 99)
   private Integer age;
   
//...
//Getters and Setters
}

Note

Bean validation in both JavaServer Faces and RichFaces requires the JSR-303 implementation. The implementation is bundled with JEE 6 Application Server.

If using Tomcat or another simple servlet container, add the validation-api Java Archive and a validation provider (such as Hibernate Validator) to your application libraries.

⁠8.1. `<rich:validator>` client-side validation

The validation built in to JavaServer Faces 2 occurs on the server side. The <rich:validator> behavior adds client-side validation to a control based on registered server-side validators. It provides this validation without the need to reproduce the server-side annotations. The <rich:validator> behavior triggers all client validator annotations listed in the relevant managed bean.

⁠8.1.1. Basic usage

The <rich:validator> behavior is added as a child element to any input control. The value of the input control must reference a managed bean. The content of the input control validates on the client-side based on registered server-side validators included in the managed bean.

⁠

Example 8.2. Basic usage

<h:inputText value="#{userBean.name}">
   <rich:validator/>
</h:inputText>

Note

JSF validation tags, such as <f:validateLength> and <f:validateDoubleRange> tags, can be declared alongside <rich:validator> behaviors. However, because this duplicates the validation processes at both the view and model level, it is not recommended.

⁠8.1.2. Messages from client-side validators

Use the <rich:message> and <rich:messages> components to display validation messages. The for attribute of the <rich:message> component references the id identifier of the input control being validated.

⁠

Example 8.3. Messages

<rich:panel header="User information">
   <h:panelGrid columns="3">
   
      <h:outputText value="Name:" />
      <h:inputText value="#{validationBean.name}" id="name">
         <rich:validator />
      </h:inputText>
      <rich:message for="name" />
      
      <h:outputText value="Email" />
      <h:inputText value="#{validationBean.email}" id="email">
         <rich:validator />
      </h:inputText>
      <rich:message for="email" />
      
      <h:outputText value="Age" />
      <h:inputText value="#{validationBean.age}" id="age">
         <rich:validator />
      </h:inputText>
      <rich:message for="age" />
      
      <h:outputText value="I agree the terms" />
      <h:selectBooleanCheckbox value="#{validationBean.agree}" id="agree">
         <rich:validator/>
      </h:selectBooleanCheckbox>
      <rich:message for="agree" />
      
   </h:panelGrid>
</rich:panel>

Failed validation checks are reported using <rich:message> components. The validation annotations in the managed bean are outlined in Example 8.1, “JSR-303 validation annotations”.

⁠8.1.3. Validation triggers

Use the event attribute to specify which event on the input control triggers the validation process. By default, the <rich:validator> behavior triggers validation when the input control is changed (event="change").

⁠

Example 8.4. Validation triggers

<h:inputText value="#{userBean.name}">
   <rich:validator event="keyup"/>
</h:inputText>

The event attribute is changed to the keyup event, such that validation takes place after each key press.

⁠8.1.4. Ajax fall-backs

If no client-side validation method exists for a registered server-side validator, Ajax fall-back is used. The <rich:validator> behavior invokes all available client-side validators. If all the client-side validators return valid, RichFaces performs an Ajax request to invoke the remaining validators on the server side.

⁠8.1.5. Reference data

client-behavior-renderer-type: org.richfaces.ClientValidatorRenderer
behavior-id: org.richfaces.behavior.ClientValidator
handler-class: org.richfaces.view.facelets.html.ClientValidatorHandler
behavior-class: org.ajax4jsf.component.behavior.ClientValidatorImpl
client-behavior-renderer-class: org.richfaces.renderkit.html.ClientValidatorRenderer