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(jakarta.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.
The UIComponent represented by this element is created with the appropriate
Application.createComponent() method.
Each attribute specified in the markup is correctly applied to the component instance, as specified in the VDLDocs for this element.
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.
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(jakarta.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.
The rendererType property of the component is set properly.
UIComponent.pushComponentToEL(jakarta.faces.context.FacesContext, jakarta.faces.component.UIComponent) is called on the newly created component.
The next handler in the facelet chain is applied. This will cause the component to be populated with children.
The component is added to its parent in the view.
UIComponent.popComponentFromEL(jakarta.faces.context.FacesContext) is called on the newly created component.
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(jakarta.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(jakarta.faces.view.facelets.FaceletContext, jakarta.faces.component.UIComponent, jakarta.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(jakarta.faces.view.facelets.FaceletContext, jakarta.faces.component.UIComponent, jakarta.faces.component.UIComponent).
delegateFactorynextHandler, tag, tagId| Constructor and Description |
|---|
ComponentHandler(ComponentConfig config)
Leverage the |
| Modifier and Type | Method and Description |
|---|---|
UIComponent |
createComponent(FaceletContext ctx)
Subclasses that wish to take over the task of instantiating the |
ComponentConfig |
getComponentConfig()
Returns the component configuration, a component-type/renderer-type pair.
|
protected TagHandlerDelegate |
getTagHandlerDelegate()
Get the tag handler delegate. |
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. |
apply, applyNextHandler, createMetaRuleset, getBinding, getTag, getTagAttribute, getTagId, isDisabled, setAttributesgetAttribute, getRequiredAttribute, toStringpublic ComponentHandler(ComponentConfig config)
Leverage the TagHandlerDelegateFactory provided by the implementation to create an instance of
TagHandlerDelegate designed for use with ComponentHandler.
config - the configuration for this handler.protected TagHandlerDelegate getTagHandlerDelegate()
DelegatingMetaTagHandlerGet the tag handler delegate.
Code that extends from DelegatingMetaTagHandler (directly or indirectly, as through extending ComponentHandler) must take care to decorate, not replace, the TagHandlerDelegate instance returned by this method. Failure to do so may produce unexpected results.
getTagHandlerDelegate in class DelegatingMetaTagHandlerpublic ComponentConfig getComponentConfig()
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.
ctx - the FaceletContext for this view executionUIComponentpublic 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.
ctx - the FaceletContext for this view executionc - the UIComponent that has just been created.parent - the parent UIComponent of the component represented by this element instance.public void onComponentPopulated(FaceletContext ctx, UIComponent c, UIComponent parent)
This method is guaranteed to be called after the component has been populated with children.
ctx - the FaceletContext for this view executionc - the UIComponent that has just been populated with children.parent - the parent UIComponent of the component represented by this element instance.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.
component - the component you wish to modifynull and the component is new during this run of the
lifecycle.