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.
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(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.
The rendererType property of the component is set properly.
UIComponent.pushComponentToEL(javax.faces.context.FacesContext, javax.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(javax.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(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).
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() |
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.