001 // Copyright 2004, 2005 The Apache Software Foundation 002 // 003 // Licensed under the Apache License, Version 2.0 (the "License"); 004 // you may not use this file except in compliance with the License. 005 // You may obtain a copy of the License at 006 // 007 // http://www.apache.org/licenses/LICENSE-2.0 008 // 009 // Unless required by applicable law or agreed to in writing, software 010 // distributed under the License is distributed on an "AS IS" BASIS, 011 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012 // See the License for the specific language governing permissions and 013 // limitations under the License. 014 015 package org.apache.tapestry.event; 016 017 import java.util.EventListener; 018 019 /** 020 * An interface for objects that want to take part in the validation of the page. 021 * 022 * @author Mindbridge 023 * @since 3.0 024 **/ 025 026 public interface PageValidateListener extends EventListener 027 { 028 /** 029 * Invoked by the page from its 030 * {@link org.apache.tapestry.IPage#validate(org.apache.tapestry.IRequestCycle)} method. 031 * 032 * <p>May throw a {@link org.apache.tapestry.PageRedirectException}, to redirect the user 033 * to an appropriate part of the system (such as, a login page). 034 **/ 035 036 public void pageValidate(PageEvent event); 037 }