javax.faces.view.facelets: abstract public class: MetaTagHandler

javax.faces.view.facelets
abstract public class: MetaTagHandler [javadoc | source]

java.lang.Object
   javax.faces.view.facelets.TagHandler
      javax.faces.view.facelets.MetaTagHandler

All Implemented Interfaces:
FaceletHandler

Direct Known Subclasses:
ValidatorHandler, FaceletsAttachedObjectHandler, ConverterHandler, DelegatingMetaTagHandler, ComponentHandler, BehaviorHandler

Every kind of markup element in Facelets VDL that has attributes that need to take action on a JSF Java API artifact is associated with an instance of this class. This class is an abstraction to enable a rule based method for directing how different kinds of elements take different kinds of actions in the JSF Java API. For example, consider this markup:

<h:inputText value="#{user.userid}" 
valueChangeListener="#{user.newUserId}" />

This markup element corresponds to an instance of javax.faces.component.html.HtmlInputText in the view. HtmlImputText has a number of attributes that are to be exposed to the page author. HtmlInputText also implements javax.faces.component.EditableValueHolder , which extends javax.faces.component.ValueHolder . Each of these interfaces also expose a number of attributes to the page author.

Facelets employes the strategy pattern to allow the manner in which all possible attributes are handled based on the nature of the JSF Java API artifact associated with the markup element.

Subclasses override the #createMetaRuleset method to return a MetaRuleset instance encapsulating all the strategies for all the attributes that make sense for this particular markup element. The runtime calls the #setAttributes(FaceletContext, Object) method to cause those rules to be executed and applied.

since: 2.0 -

Fields inherited from javax.faces.view.facelets.TagHandler:
tagId, tag, nextHandler

Constructor:
public MetaTagHandler(TagConfig config) { super(config); }

Method from javax.faces.view.facelets.MetaTagHandler Summary:
createMetaRuleset, setAttributes

Methods from javax.faces.view.facelets.TagHandler:
getAttribute, getRequiredAttribute, toString

Methods from java.lang.Object:
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from javax.faces.view.facelets.MetaTagHandler Detail:
abstract protected MetaRuleset createMetaRuleset(Class type) Extend this method in order to add your own rules.
protected void setAttributes(FaceletContext ctx, Object instance) { if (instance != null) { Class type = instance.getClass(); if (mapper == null \|\| !this.lastType.equals(type)) { this.lastType = type; this.mapper = this.createMetaRuleset(type).finish(); } this.mapper.applyMetadata(ctx, instance); } } Invoking/extending this method will cause the results of the created MetaRuleset to auto-wire state to the passed instance.

Method from javax.faces.view.facelets.MetaTagHandler Detail:

 abstract protected MetaRuleset createMetaRuleset(Class type)Extend this method in order to add your own rules.

 protected  void setAttributes(FaceletContext ctx,
    Object instance) {
        if (instance != null) {
            Class type = instance.getClass();
            if (mapper == null || !this.lastType.equals(type)) {
                this.lastType = type;
                this.mapper = this.createMetaRuleset(type).finish();
            }
            this.mapper.applyMetadata(ctx, instance);
        }
}

Invoking/extending this method will cause the results of the created MetaRuleset to auto-wire state to the passed instance.