Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
RenderBlock |
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| 2.0;2 |
1 | // Copyright 2004, 2005 The Apache Software Foundation | |
2 | // | |
3 | // Licensed under the Apache License, Version 2.0 (the "License"); | |
4 | // you may not use this file except in compliance with the License. | |
5 | // You may obtain a copy of the License at | |
6 | // | |
7 | // http://www.apache.org/licenses/LICENSE-2.0 | |
8 | // | |
9 | // Unless required by applicable law or agreed to in writing, software | |
10 | // distributed under the License is distributed on an "AS IS" BASIS, | |
11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
12 | // See the License for the specific language governing permissions and | |
13 | // limitations under the License. | |
14 | ||
15 | package org.apache.tapestry.components; | |
16 | ||
17 | import org.apache.tapestry.AbstractComponent; | |
18 | import org.apache.tapestry.IMarkupWriter; | |
19 | import org.apache.tapestry.IRequestCycle; | |
20 | ||
21 | /** | |
22 | * Renders the text and components wrapped by a {@link Block}component. [ <a | |
23 | * href="../../../../../components/general/renderblock.html">Component Reference | |
24 | * </a>] | |
25 | * <p> | |
26 | * It is possible for an RenderBlock to obtain a Block from a page | |
27 | * <em>other than</em> the render page. This works, even when the Block | |
28 | * contains links, forms and form components. The action and direct services | |
29 | * will create URLs that properly address this situation. | |
30 | * <p> | |
31 | * However, because the rendering page can't know ahead of time about these | |
32 | * foreign Blocks, {@link org.apache.tapestry.event.PageBeginRenderListener} and | |
33 | * {@link org.apache.tapestry.event.PageEndRenderListener} methods (for | |
34 | * components and objects of the foreign page) via RenderBlock will <em>not</em> | |
35 | * be executed. This specifically affects the methods of the | |
36 | * {@link org.apache.tapestry.event.PageBeginRenderListener} and | |
37 | * {@link org.apache.tapestry.event.PageEndRenderListener} interfaces. | |
38 | * <p> | |
39 | * Before rendering its {@link Block}, RenderBlock will set itself as the | |
40 | * Block's inserter, and will reset the inserter after the {@link Block}is | |
41 | * rendered. This gives the components contained in the {@link Block}access to | |
42 | * its inserted environment via the RenderBlock. In particular this allows the | |
43 | * contained components to access the informal parameters of the RenderBlock | |
44 | * which effectively allows parameters to be passed to the components contained | |
45 | * in a Block. | |
46 | * | |
47 | * @author Howard Lewis Ship | |
48 | */ | |
49 | ||
50 | 0 | public abstract class RenderBlock extends AbstractComponent |
51 | { | |
52 | ||
53 | /** | |
54 | * If block is not null, then | |
55 | * {@link Block#renderForComponent(IMarkupWriter, IRequestCycle, IComponent)} | |
56 | * is invoked. | |
57 | */ | |
58 | ||
59 | protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle) | |
60 | { | |
61 | 0 | Block block = getBlock(); |
62 | ||
63 | 0 | if (block == null) return; |
64 | ||
65 | 0 | block.renderForComponent(writer, cycle, this); |
66 | 0 | } |
67 | ||
68 | public abstract Block getBlock(); | |
69 | ||
70 | } |