# a4j

## Tag region

- Description:

    The <a4j:region> component specifies a part of the JSF component tree to be processed on the server. The region causes all the a4j and rich Ajax controls to execute: decoding, validating, and updating the model. The region causes these components to execute even if not explicitly declared. As such, processing areas can more easily be marked using a declarative approach.

    Regions can be nested, in which case only the parent region of the component initiating the request will be processed.

    @author Nick Belaevski

- Component Information
  Info | Value
  --- | ---
  Component Type | `org.richfaces.Region`
  Display Name | None
  Handler Class | None
  Renderer Type | None
  Description | The <a4j:region> component specifies a part of the JSF component tree to be processed on the server. The region causes all the a4j and rich Ajax controls to execute: decoding, validating, and updating the model. The region causes these components to execute even if not explicitly declared. As such, processing areas can more easily be marked using a declarative approach. Regions can be nested, in which case only the parent region of the component initiating the request will be processed. @author Nick Belaevski

- Attributes
  Name | Required | Type | Description
  --- | --- | --- | ---
  `binding` | `false` | `javax.el.ValueExpression` (must evaluate to `javax.faces.component.UIComponent`) | The value binding expression used to wire up this component to a component property of a JavaBean class
  `id` | `false` | `javax.el.ValueExpression` (must evaluate to `java.lang.String`) | The component identifier for this component. This value must be unique within the closest parent component that is a naming container.
  `rendered` | `false` | `javax.el.ValueExpression` (must evaluate to `boolean`) | Flag indicating whether or not this component should be rendered (during Render Response Phase), or processed on any subsequent form submit. The default value for this property is true.

Output generated by Vdldoc View Declaration Language Documentation Generator.