Class ComponentHandler
- All Implemented Interfaces:
FaceletHandler
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 appropriateApplication.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 theLocation
for this element into the component attributeMap
under the key given by the value of the symbolic constantUIComponent.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 itsUniqueIdVendor.createUniqueId(javax.faces.context.FacesContext, java.lang.String)
method must be called to derive the id. If no such instance can be found, callUIViewRoot.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 overridecreateComponent(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 theUIComponent
.To be notified of creation of the
UIComponent
instance, subclasses may overrideonComponentCreated(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 overrideonComponentPopulated(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
ConstructorDescriptionComponentHandler
(ComponentConfig config) Leverage theTagHandlerDelegateFactory
provided by the implementation to create an instance ofTagHandlerDelegate
designed for use withComponentHandler
. -
Method Summary
Modifier and TypeMethodDescriptionSubclasses that wish to take over the task of instantiating theUIComponent
instance corresponding to this tag handler my override this method to do so.protected TagHandlerDelegate
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.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
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Constructor Details
-
ComponentHandler
Leverage the
TagHandlerDelegateFactory
provided by the implementation to create an instance ofTagHandlerDelegate
designed for use withComponentHandler
.- Since:
- 2.0
-
-
Method Details
-
getTagHandlerDelegate
- Specified by:
getTagHandlerDelegate
in classDelegatingMetaTagHandler
-
getComponentConfig
-
createComponent
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. Anull
return from this method will cause theTagHandlerDelegate
for instance to create the component instead.- Since:
- 2.2
-
onComponentCreated
This method is guaranteed to be called after the component has been created but before it has been populated with children.
- Parameters:
ctx
- theFaceletContext
for this view executionc
- theUIComponent
that has just been created.parent
- the parentUIComponent
of the component represented by this element instance.- Since:
- 2.0
-
onComponentPopulated
This method is guaranteed to be called after the component has been populated with children.
- Parameters:
ctx
- theFaceletContext
for this view executionc
- theUIComponent
that has just been populated with children.parent
- the parentUIComponent
of the component represented by this element instance.- Since:
- 2.0
-
isNew
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
-