Package javax.faces.view.facelets

Class MetaRule


  • 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 JSF 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.

    1. 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.

    2. 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).

    Since:
    2.0

    • Constructor Summary

      Constructors 
      Constructor Description
      MetaRule​()  

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method 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 name, in the context of this particular concrete subclass of MetaRule.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • MetaRule

        public MetaRule​()

    • Method Detail

      • applyRule

        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.

        Parameters:
        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.
        Returns:
        the Metadata.
        Since:
        2.0