java.lang.Object
- javax.faces.view.facelets.TagHandler
- - javax.faces.view.facelets.MetaTagHandler
  - - javax.faces.view.facelets.DelegatingMetaTagHandler
    - - javax.faces.view.facelets.ComponentHandler

All Implemented Interfaces:

FaceletHandler
```
public class ComponentHandler
extends DelegatingMetaTagHandler
```
Public base class for markup element instances that map to UIComponent instances in the view.
Instances of this class are created and passed to TagHandlerDelegateFactory.createComponentHandlerDelegate(javax.faces.view.facelets.ComponentHandler) when a tag corresponding to this particular component is encountered in a Facelet view. A custom tag handler for a component, converter, validator, or behavior must extend from this class. In this way, this instance acts as a delegate for the implementation private tag handler. Such a subclass may choose to override as many or as few methods from this base class as desired. If the subclass wants to completely override the action of the implementation specific tag for which this component is the delegate, it must override the apply() method and make it take the following actions, in this order. These actions must only happen the first time this facelet is applied for each user. Subsequent applications must take no action.
1. The UIComponent represented by this element is created with the appropriate Application.createComponent() method.
2. Each attribute specified in the markup is correctly applied to the component instance, as specified in the VDLDocs for this element.
3. If project stage is ProjectStage.Development, Put the Location for this element into the component attribute Map under the key given by the value of the symbolic constant UIComponent.VIEW_LOCATION_KEY.
4. Set the id of the component. If the id is specified manually by the page author, that value must be set as the id. Otherwise, the closest ancestor component that is an instance of UniqueIdVendor must be located and its UniqueIdVendor.createUniqueId(javax.faces.context.FacesContext, java.lang.String) method must be called to derive the id. If no such instance can be found, call UIViewRoot.createUniqueId() to derive the id.
5. The rendererType property of the component is set properly.
6. onComponentCreated(javax.faces.view.facelets.FaceletContext, javax.faces.component.UIComponent, javax.faces.component.UIComponent) is called.
7. UIComponent.pushComponentToEL(javax.faces.context.FacesContext, javax.faces.component.UIComponent) is called on the newly created component.
8. The next handler in the facelet chain is applied. This will cause the component to be populated with children.
9. The component is added to its parent in the view.
10. UIComponent.popComponentFromEL(javax.faces.context.FacesContext) is called on the newly created component.
11. Call UIComponent.markInitialState().
A common use case for extending this class is to gain access to the process by which the Facelets runtime creates component instances corresponding to markup in a Facelets view. These three methods are useful in such cases.
- To control the instantiation of the UIComponent instance, subclasses may override createComponent(javax.faces.view.facelets.FaceletContext). If this method is not overridden, the tag handler for which this instance is the delegate will take the necessary action to instantiate the UIComponent.
- To be notified of creation of the UIComponentinstance, subclasses may override onComponentCreated(javax.faces.view.facelets.FaceletContext, javax.faces.component.UIComponent, javax.faces.component.UIComponent).
- To be notified that the freshly created UIComponent instance has been populated with children as a result of execution of child tag handlers, subclasses may override onComponentPopulated(javax.faces.view.facelets.FaceletContext, javax.faces.component.UIComponent, javax.faces.component.UIComponent).
Since:

2.0

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
`ComponentHandler(ComponentConfig config)` Leverage the `TagHandlerDelegateFactory` provided by the implementation to create an instance of `TagHandlerDelegate` designed for use with `ComponentHandler`.

ComponentHandler (Java(TM) EE 7 Specification APIs) Home of API Java Contents Haut

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`UIComponent`	`createComponent(FaceletContext ctx)` Subclasses that wish to take over the task of instantiating the `UIComponent` instance corresponding to this tag handler my override this method to do so.
`ComponentConfig`	`getComponentConfig()`
`protected TagHandlerDelegate`	`getTagHandlerDelegate()`
`static boolean`	`isNew(UIComponent component)` Determine if the passed component is not null and if it's new to the tree.
`void`	`onComponentCreated(FaceletContext ctx, UIComponent c, UIComponent parent)` This method is guaranteed to be called after the component has been created but before it has been populated with children.
`void`	`onComponentPopulated(FaceletContext ctx, UIComponent c, UIComponent parent)` This method is guaranteed to be called after the component has been populated with children.

ComponentHandler (Java(TM) EE 7 Specification APIs) Home of API Java Contents Haut

Methods inherited from class javax.faces.view.facelets.DelegatingMetaTagHandler
apply, applyNextHandler, createMetaRuleset, getBinding, getTag, getTagAttribute, getTagId, isDisabled, 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

- Constructor Detail
  - ComponentHandler
```
public ComponentHandler(ComponentConfig config)
```
    Leverage the TagHandlerDelegateFactory provided by the implementation to create an instance of TagHandlerDelegate designed for use with ComponentHandler.
    
    Since:
    
    2.0
- Method Detail
  - getTagHandlerDelegate
```
protected TagHandlerDelegate getTagHandlerDelegate()
```
    Specified by:
    
    getTagHandlerDelegate in class DelegatingMetaTagHandler
  - getComponentConfig
```
public ComponentConfig getComponentConfig()
```
  - createComponent
```
public UIComponent createComponent(FaceletContext ctx)
```
    Subclasses that wish to take over the task of instantiating the UIComponent instance corresponding to this tag handler my override this method to do so. A null return from this method will cause the TagHandlerDelegate for instance to create the component instead.
    
    Since:
    
    2.2
  - onComponentCreated
```
public void onComponentCreated(FaceletContext ctx,
                               UIComponent c,
                               UIComponent parent)
```
    This method is guaranteed to be called after the component has been created but before it has been populated with children.
    
    Parameters:
    
    ctx - the FaceletContext for this view execution
    
    c - the UIComponent that has just been created.
    
    parent - the parent UIComponent of the component represented by this element instance.
    
    Since:
    
    2.0
  - onComponentPopulated
```
public void onComponentPopulated(FaceletContext ctx,
                                 UIComponent c,
                                 UIComponent parent)
```
    This method is guaranteed to be called after the component has been populated with children.
    
    Parameters:
    
    ctx - the FaceletContext for this view execution
    
    c - the UIComponent that has just been populated with children.
    
    parent - the parent UIComponent of the component represented by this element instance.
    
    Since:
    
    2.0
  - isNew
```
public static boolean isNew(UIComponent component)
```
    Determine if the passed component is not null and if it's new to the tree. This operation can be used for determining if attributes should be wired to the component.
    
    Parameters:
    
    component - the component you wish to modify
    
    Since:
    
    2.0

Document created the 11/06/2005, last modified the 18/08/2025
Source of the printed document:https://www.gaudry.be/en/java-api-javaee-rf-javax/faces/view/facelets/ComponentHandler.html

The infobrol is a personal site whose content is my sole responsibility. The text is available under CreativeCommons license (BY-NC-SA). More info on the terms of use and the author.

References

Manuel PHP : https://docs.oracle.com, ComponentHandler (Java(TM) EE 7 Specification APIs)

These references and links indicate documents consulted during the writing of this page, or which may provide additional information, but the authors of these sources can not be held responsible for the content of this page.
The author of this site is solely responsible for the way in which the various concepts, and the freedoms that are taken with the reference works, are presented here. Remember that you must cross multiple source information to reduce the risk of errors.

Class ComponentHandler

Field Summary

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

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

Constructor Summary

Method Summary

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

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

Methods inherited from class java.lang.Object

Constructor Detail

ComponentHandler

Method Detail

getTagHandlerDelegate

getComponentConfig

createComponent

onComponentCreated

onComponentPopulated

isNew

References