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package javax.faces.view.facelets;

import java.io.IOException;
import javax.faces.component.UIComponent;

/**
 * <p class="changed_added_2_0">This is the root class for markup
 * elements in Facelets VDL.  Facelets is XHTML, and XHTML is XML, and
 * the root unit of abstraction in XML is the element.  A
 * <code>FaceletHandler</code> instance represents an XML element at
 * runtime.  Two direct implementations exist to embody the contract for
 * more specific behavior.</p>
 *
 * <div class="changed_added_2_0">

 * <dl>

 * <dt>{@link CompositeFaceletHandler}</dt>

 * <dd>A container for other <code>FaceletHandler</code>s</dd>

 * <dt>{@link TagHandler}</dt>

 * <dd>The foundation class for <code>FaceletHandler</code>s associated
 * with markup in a Facelet document.</dd>

 * </dl>

 * </div>

 * @since 2.0
 */
public interface FaceletHandler {

    /**
     * <p class="changed_added_2_0">Process changes on a particular
     * UIComponent</p>
     * 
     * @param ctx the current FaceletContext instance for this execution
     * @param parent the parent UIComponent to operate upon

     * @throws IOException if unable to load <code>relativePath</code>

     * @throws FaceletException if unable to parse the markup loaded from <code>relativePath</code>

     * @throws FacesException if unable to create child <code>UIComponent</code> instances

     * @throws ELException if any of the expressions in the markup
     * loaded from <code>relativePath</code> fail

     * @since 2.0

     */
    public void apply(FaceletContext ctx, UIComponent parent)
    throws IOException;
}
