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, jakarta.faces.view.facelets.TagAttribute, jakarta.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, jakarta.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(jakarta.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.