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 015package org.apache.tapestry.wml; 016 017import org.apache.hivemind.HiveMind; 018import org.apache.tapestry.AbstractComponent; 019import org.apache.tapestry.IMarkupWriter; 020import org.apache.tapestry.IRequestCycle; 021 022/** 023 * The do element provides a general mechanism for the user to act upon the current card, in other 024 * words a card-level user interface element. The representation of the do element is user agent 025 * dependent and the author must only assume that the element is mapped to a unique user interface 026 * widget that the user can activate. For example, the widget mapping may be to a graphically 027 * rendered button, a soft or function key, a voice-activated command sequence, or any other 028 * interface that has a simple "activate" operation with no inter-operation persistent state. The do 029 * element may appear at both the card and deck-level. 030 * 031 * @author David Solis 032 * @since 3.0 033 */ 034 035public abstract class Do extends AbstractComponent 036{ 037 /** 038 * @see AbstractComponent#renderComponent(IMarkupWriter, IRequestCycle) 039 */ 040 041 protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle) 042 { 043 boolean render = !cycle.isRewinding(); 044 045 if (render) 046 { 047 writer.begin("do"); 048 049 writer.attribute("type", getType()); 050 051 String label = getLabel(); 052 if (HiveMind.isNonBlank(label)) 053 writer.attribute("label", label); 054 055 renderInformalParameters(writer, cycle); 056 } 057 058 renderBody(writer, cycle); 059 060 if (render) 061 writer.end(); 062 } 063 064 public abstract String getType(); 065 066 public abstract String getLabel(); 067}