001// Copyright 2008, 2009 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 015package org.apache.tapestry5.corelib.base; 016 017import org.apache.tapestry5.BindingConstants; 018import org.apache.tapestry5.Link; 019import org.apache.tapestry5.MarkupConstants; 020import org.apache.tapestry5.MarkupWriter; 021import org.apache.tapestry5.annotations.Environmental; 022import org.apache.tapestry5.annotations.Parameter; 023import org.apache.tapestry5.ioc.annotations.Inject; 024import org.apache.tapestry5.services.ClientBehaviorSupport; 025import org.apache.tapestry5.services.Request; 026 027/** 028 * Base class for link-generating components that are based on a component event request. Such events have an event 029 * context and may also update a {@link org.apache.tapestry5.corelib.components.Zone}. 030 */ 031public abstract class AbstractComponentEventLink extends AbstractLink 032{ 033 /** 034 * The context for the link (optional parameter). This list of values will be converted into strings and included in 035 * the URI. The strings will be coerced back to whatever their values are and made available to event handler 036 * methods. 037 */ 038 @Parameter 039 private Object[] context; 040 041 /** 042 * Binding the zone parameter turns the link into a an Ajax control that causes the related zone to be updated. 043 */ 044 @Parameter(defaultPrefix = BindingConstants.LITERAL) 045 private String zone; 046 047 @Environmental 048 private ClientBehaviorSupport clientBehaviorSupport; 049 050 @Inject 051 private Request request; 052 053 void beginRender(MarkupWriter writer) 054 { 055 if (isDisabled()) return; 056 057 Link link = createLink(context); 058 059 writeLink(writer, link); 060 061 if (zone != null) 062 { 063 if (!request.isXHR()) 064 writer.getElement().forceAttributes(MarkupConstants.ONCLICK, MarkupConstants.WAIT_FOR_PAGE); 065 066 clientBehaviorSupport.linkZone(getClientId(), zone, link); 067 } 068 } 069 070 /** 071 * Invoked to create the Link that will become the href attribute of the output. 072 * 073 * @param eventContext the context as an object array, possibly null 074 */ 075 protected abstract Link createLink(Object[] eventContext); 076 077 void afterRender(MarkupWriter writer) 078 { 079 if (isDisabled()) return; 080 081 writer.end(); // <a> 082 } 083}