public abstract class MetaRule
extends java.lang.Object
The root class of the abstraction that dictates
how attributes on a markup element in a Facelets VDL page are wired to the
Jakarta Server Faces API object instance associated with that element. The single method on
this interface, applyRule(java.lang.String, javax.faces.view.facelets.TagAttribute, javax.faces.view.facelets.MetadataTarget), returns an encapsulation of the behavior
that actually does the work of handling the attribute and its value. There
are implementations of specific concrete subclasses of this class for all the
basic kinds of elements that appear in Facelets VDL pages: components,
non-components, and attached objects.
For example, consider this markup:
<h:inputText value="#{user.userid}"
valueChangeListener="#{user.newUserId}" />
Two MetaRule instances are involved in this example.
The first has an applyRule() method that returns a
Metadata instance that, when its applyMetada() method is
called, dictates how the "value" attribute is processed: calling UIComponent.setValueExpression(java.lang.String, javax.el.ValueExpression) on the
UIComponent instance associated with the
<h:inputText> element.
The second has an applyRule() method that returns a
Metadata instance that, when its applyMetadata() method
is called, dictates how the "valueChangeListener" attribute is processed:
calling EditableValueHolder.addValueChangeListener(javax.faces.event.ValueChangeListener).
| Constructor and Description |
|---|
MetaRule() |
| Modifier and Type | Method and Description |
|---|---|
abstract Metadata |
applyRule(java.lang.String name,
TagAttribute attribute,
MetadataTarget meta)
Return an abstraction that takes appropriate
action given the kind of rule represented by the argument
|
public abstract Metadata applyRule(java.lang.String name, TagAttribute attribute, MetadataTarget meta)
Return an abstraction that takes appropriate
action given the kind of rule represented by the argument
name, in the context of this particular concrete subclass of
MetaRule. The abstraction must encapsulate the value from
the argument attribute.
name - the name for this rule. This will generally be the name of a
tag attribute in the VDL.attribute - the name/value pair for this attribute on this
particular instance of an element in the page.meta - the MetadataTarged that can be used to discern
what kind of action to encapsulate within the abstraction to be returned.Metadata.