/*
* The contents of this file are subject to the terms
* of the Common Development and Distribution License
* (the License). You may not use this file except in
* compliance with the License.
*
* You can obtain a copy of the license at
* https://jsftemplating.dev.java.net/cddl1.html or
* jsftemplating/cddl1.txt.
* See the License for the specific language governing
* permissions and limitations under the License.
*
* When distributing Covered Code, include this CDDL
* Header Notice in each file and include the License file
* at jsftemplating/cddl1.txt.
* If applicable, add the following below the CDDL Header,
* with the fields enclosed by brackets [] replaced by
* you own identifying information:
* "Portions Copyrighted [year] [name of copyright owner]"
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
*/
package com.sun.jsftemplating.layout.descriptors;
import java.io.IOException;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import com.sun.jsftemplating.el.PermissionChecker;
import com.sun.jsftemplating.layout.LayoutDefinitionManager;
import com.sun.jsftemplating.layout.event.AfterLoopEvent;
import com.sun.jsftemplating.layout.event.BeforeLoopEvent;
/**
* <p> This class defines a LayoutWhile {@link LayoutElement}. The
* LayoutWhile provides the functionality necessary to iteratively
* display a portion of the layout tree. The condition is a boolean
* equation and may use "$...{...}" type expressions to substitute
* values.</p>
*
* @see com.sun.jsftemplating.el.VariableResolver
* @see com.sun.jsftemplating.el.PermissionChecker
*
* @author Ken Paulsen (ken.paulsen@sun.com)
*/
public class LayoutWhile extends LayoutIf {
private static final long serialVersionUID = 1L;
/**
* Constructor
*/
public LayoutWhile(LayoutElement parent, String condition) {
super(parent, condition,
LayoutDefinitionManager.getGlobalComponentType(null, "while"));
}
/**
* <p> This method always returns true. The condition is checked in
* {@link #shouldContinue(UIComponent)} instead of here because
* the {@link #encode(FacesContext, UIComponent)} method
* evaluates the condition and calls the super. Performing the check
* here would cause the condition to be evaluated twice.</p>
*
* @param context The FacesContext
* @param component The UIComponent
*
* @return true
*/
public boolean encodeThis(FacesContext context, UIComponent component) {
return true;
}
/**
* <p> This method returns true if the condition of this LayoutWhile is
* met, false otherwise. This provides the functionality for
* iteratively displaying a portion of the layout tree.</p>
*
* @param component The UIComponent
*
* @return true if children are to be rendered, false otherwise.
*/
protected boolean shouldContinue(UIComponent component) {
PermissionChecker checker =
new PermissionChecker(this, component,
(String) getOption("condition"));
return checker.hasPermission();
}
/**
* <p> This implementation overrides the parent <code>encode</code>
* method. It does this to cause the encode process to loop while
* {@link #shouldContinue(UIComponent)} returns
* true. Currently there is no infinite loop checking, so be
* careful.</p>
*
* @param context The FacesContext
* @param component The UIComponent
*/
public void encode(FacesContext context, UIComponent component) throws IOException {
dispatchHandlers(context, BEFORE_LOOP,
new BeforeLoopEvent((UIComponent) component));
while (shouldContinue(component)) {
super.encode(context, component);
}
dispatchHandlers(context, AFTER_LOOP,
new AfterLoopEvent((UIComponent) component));
}
/**
* <p> This is the event "type" for
* {@link com.sun.jsftemplating.layout.descriptors.handler.Handler}
* elements to be invoked after this LayoutWhile is processed
* (outside loop).</p>
*/
public static final String AFTER_LOOP = "afterLoop";
/**
* <p> This is the event "type" for
* {@link com.sun.jsftemplating.layout.descriptors.handler.Handler}
* elements to be invoked before this LayoutWhile is processed
* (outside loop).</p>
*/
public static final String BEFORE_LOOP = "beforeLoop";
}