Classes in this File | Line Coverage | Branch Coverage | Complexity | |||||||
BlockRenderer |
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| 1.0;1 |
1 | // Copyright 2004, 2005 The Apache Software Foundation |
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2 | // |
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3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
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4 | // you may not use this file except in compliance with the License. |
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5 | // You may obtain a copy of the License at |
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6 | // |
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7 | // http://www.apache.org/licenses/LICENSE-2.0 |
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8 | // |
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9 | // Unless required by applicable law or agreed to in writing, software |
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10 | // distributed under the License is distributed on an "AS IS" BASIS, |
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11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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12 | // See the License for the specific language governing permissions and |
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13 | // limitations under the License. |
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14 | ||
15 | package org.apache.tapestry.components; |
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16 | ||
17 | import org.apache.tapestry.IMarkupWriter; |
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18 | import org.apache.tapestry.IRender; |
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19 | import org.apache.tapestry.IRequestCycle; |
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20 | ||
21 | /** |
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22 | * An implementation of IRender that renders a Block component. |
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23 | * <p> |
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24 | * The BlockRenderer allows the contents of a {@link Block} to be rendered via |
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25 | * {@link IRender}. It can be used in cases when an {@link IRender} object is |
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26 | * required as an argument or a binding to render a part of a Component. To |
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27 | * provide a complicated view, it could be defined in a {@link Block} and then |
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28 | * returned encapsulated in a BlockRenderer. |
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29 | * <p> |
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30 | * It is important to note that a special care has to be taken if the |
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31 | * BlockRenderer is used within an inner class of a component or a page. In such |
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32 | * a case the instance of the component that created the inner class may not be |
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33 | * the currently active instance in the RequestCycle when the BlockRenderer is |
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34 | * required. Thus, calling getComponent("blockName") to get the block component |
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35 | * may return a Block component that is not initialized for this RequestCycle. |
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36 | * <p> |
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37 | * To avoid similar problems, the ComponentAddress class could be used in |
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38 | * conjunction with BlockRenderer. Here is a quick example of how BlockRenderer |
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39 | * could be used with ComponentAddress: |
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40 | * <p> |
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41 | * <code> |
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42 | * <br>// Create a component address for the current component |
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43 | * <br>final ComponentAddress address = new ComponentAddress(this); |
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44 | * <br>return new SomeClass() { |
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45 | * <br> IRender getRenderer(IRequestCycle cycle) { |
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46 | * <br> MyComponent component = (MyComponent) address.findComponent(cycle); |
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47 | * <br> // initialize variables in the component that will be used by the block here |
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48 | * <br> return new BlockRenderer(component.getComponent("block")); |
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49 | * <br> } |
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50 | * <br>} |
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51 | * </code> |
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52 | * |
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53 | * @author mindbridge |
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54 | * @since 2.2 |
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55 | */ |
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56 | public class BlockRenderer implements IRender |
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57 | { |
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58 | ||
59 | private Block m_objBlock; |
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60 | ||
61 | /** |
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62 | * Creates a new BlockRenderer that will render the content of the argument. |
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63 | * |
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64 | * @param objBlock |
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65 | * the Block to be rendered |
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66 | */ |
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67 | public BlockRenderer(Block objBlock) |
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68 | 0 | { |
69 | 0 | m_objBlock = objBlock; |
70 | 0 | } |
71 | ||
72 | /** |
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73 | * @see org.apache.tapestry.IRender#render(IMarkupWriter, IRequestCycle) |
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74 | */ |
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75 | public void render(IMarkupWriter writer, IRequestCycle cycle) |
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76 | { |
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77 | 0 | m_objBlock.renderBody(writer, cycle); |
78 | 0 | } |
79 | ||
80 | } |