tapestry/src/site/xdoc/usersguide/script.xml - tapestry4 - Git at Google

 <?xml version="1.0" encoding="UTF-8"?>
 <!--
     Copyright 2005 The Apache Software Foundation

     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
     You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

     Unless required by applicable law or agreed to in writing, software
     distributed under the License is distributed on an "AS IS" BASIS,
     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     See the License for the specific language governing permissions and
     limitations under the License.
 -->
 <document>
     <properties>
         <title>Script Template Specification DTDs</title>
     </properties>
     <body>

         <section name="Script Template Specification DTDs">
             <p>
                 Script template specifications are the odd man out when it comes to Tapestry XML
                 files as they don't use the same DTD as the
                 <a href="spec.html">other specifications</a>
                 .
             </p>

             <p>
                 Script templates are used to dynamically generate JavaScript to support client-side
                 behaviors associated with components. Tapestry is all about dynamically renderered,
                 customized HTML, so it makes sense that dynamically rendered, customize JavaScript
                 to complement that HTML should also be supported.
             </p>

             <p>
                 Script template files are parsed into memory as instances of
                 <a href="../apidocs/org/apache/tapestry/IScript.html">IScript</a>
                 . These script template
                 <em>objects</em>
                 may be executed to generate the JavaScript.
             </p>

             <p>
                 Many different script template objects may be executed during the course of
                 rendering a page; all the JavaScript from all the executions are organized into two
                 JavaScript blocks in the output page: the
                 <em>main body</em>
                 at the top of the page (just inside the HTML &lt;body&gt; tag), and an
                 <em>initialization block</em>
                 at the bottom of the page, (just before the HTML &lt;/body&gt; tag).
             </p>

             <p>
                 Executing a script template requires access to an
                 <a href="../apidocs/org/apache/tapestry/IScriptProcessor.html">
                     IScriptProcessor
                 </a>
                 instance; this is usually provided by the
                 <a href="../components/general/body.html">Body</a>
                 component. The script processor is responsible for managing the buffers of
                 JavaScript, and assists with generating unique ids for client-side variables and
                 functions.
             </p>

             <p>
                 A script template works with
                 <em>symbols</em>
                 , a set of key/value pairs (implements as a Map). The script operates upon the input
                 symbols and generates new output symbols along the way, while generating JavaScript.
                 In some cases, the output symbols may be used by a component when rendering HTML.
             </p>

             <p>
                 Many of the elements in a script template have a body of parsable character data. In
                 the body of an element, you may reference symbols using the Ant-like ${...} syntax.
                 I.e.
                 <code>${name}</code>
                 . In fact, the string inside the curly braces is an
                 <a href="http://www.ognl.org">OGNL</a>
                 expression, so you may create more complex expressions, such as
                 <code>${field.form.name}</code>
                 .
             </p>

             <subsection name="DOCTYPE">


                 <p>The DOCTYPE for a script template specification is:</p>

                 <source xml:space="preserve">
 &lt;!DOCTYPE script PUBLIC
   "-//Apache Software Foundation//Tapestry Script Specification 3.0//EN"
   "http://jakarta.apache.org/tapestry/dtd/Script_3_0.dtd"&gt;</source>
             </subsection><!-- DOCTYPE -->

 			<a name="script.body"></a>
             <subsection name="&lt;body&gt; element">


                 <p>
                     Appears in:
                     <a href="#script.script">&lt;script&gt;</a>
                 </p>

                 <p>
                     Allows a mix of text and control elements. This text is added to the large
                     scripting block just inside the HTML &lt;body&gt; tag.
                 </p>

                 <p>&lt;body&gt; elements:</p>

                 <source xml:space="preserve">(<em>text</em> | <a href="#script.foreach">&lt;foreach&gt;</a> | <a
                         href="#script.if">&lt;if&gt;</a> | <a href="#script.if-not">&lt;if-not&gt;</a> | <a
                         href="#script.unique">&lt;unique&gt;</a>)*</source>
             </subsection>

 			<a name="script.foreach"></a>
             <subsection name="&lt;foreach&gt; element">


                 <p>
                     Appears in:
                     <em>many</em>
                 </p>

                 <p>
                     Iterates over a list of items; this is modeled after the For component. No
                     iteration occurs if the value from the expression is null.
                 </p>

                 <table>

                     <tr>
                         <th>Name</th>
                         <th>Type</th>
                         <th>Required ?</th>
                         <th>Default Value</th>
                         <th>Description</th>
                     </tr>

                     <tr>
                         <td>key</td>
                         <td>string</td>
                         <td>no</td>
                         <td />
                         <td>Defines the symbol into which each succesive value is stored.</td>
                     </tr>

                     <tr>
                         <td>index</td>
                         <td>string</td>
                         <td>no</td>
                         <td />
                         <td>
                             Defines the symbol into which the index of the value of the current
                             iteration is stored.
                         </td>
                     </tr>

                     <tr>
                         <td>expression</td>
                         <td>string</td>
                         <td>yes</td>
                         <td />
                         <td>
                             The source of values, as an OGNL expression rooted in the symbols Map.
                         </td>
                     </tr>
                 </table>

                 <p>&lt;foreach&gt; elements:</p>

                 <source xml:space="preserve">(<em>text</em> | <a href="#script.foreach">&lt;foreach&gt;</a> | <a
                         href="#script.if">&lt;if&gt;</a> | <a href="#script.if-not">&lt;if-not&gt;</a> | <a
                         href="#script.unique">&lt;unique&gt;</a>)*</source>
             </subsection>

 			<a name="script.if"></a>
             <subsection name="&lt;if&gt; element">


                 <p>
                     Appears in:
                     <em>many</em>
                 </p>

                 <p>
                     Creates a conditional portion of the script; The body of the element is only
                     included if the expression evaulates to true.
                 </p>

                 <table>

                     <tr>
                         <th>Name</th>
                         <th>Type</th>
                         <th>Required ?</th>
                         <th>Default Value</th>
                         <th>Description</th>
                     </tr>

                     <tr>
                         <td>expression</td>
                         <td>string</td>
                         <td>yes</td>
                         <td />
                         <td>
                             The
                             <a href="http://www.ognl.org">OGNL</a>
                             expression to evaluate.
                         </td>
                     </tr>


                 </table>

                 <p>&lt;if&gt; Elements</p>

                 <source xml:space="preserve">(<em>text</em> | <a href="#script.foreach">&lt;foreach&gt;</a> | <a
                         href="#script.if">&lt;if&gt;</a> | <a href="#script.if-not">&lt;if-not&gt;</a> | <a
                         href="#script.unique">&lt;unique&gt;</a>)*</source>

             </subsection>

 			<a name="script.if-not"></a>
             <subsection name="&lt;if-not&gt; element">


                 <p>
                     Identical to the
                     <a href="#script.if">&lt;if&gt;</a>
                     element, except that the body is only included in the output if the expression
                     evaluates to
                     <strong>false</strong>
                     .
                 </p>
             </subsection>


 			<a name="script.include-script"></a>
             <subsection name="&lt;include-script&gt; element">


                 <p>
                     Inserts a reference to a static JavaScript file stored on the classpath. A
                     particular file will only be included once per rendering of a page.
                 </p>

                 <p>
                     For best performance, as much logic as possible should be shifted into static
                     JavaScript library files that are included via this element. The dynamic portion
                     of the JavaScript should really be initialization of code provided by such a
                     static JavaScript library. This optimizes that amount of data that must be sent
                     to the client web browser, as it will be able to cache the content of static
                     library files.
                 </p>

                 <p>
                     Appears in:
                     <a href="#script.script">&lt;script&gt;</a>
                 </p>

                 <table>

                     <tr>
                         <th>Name</th>
                         <th>Type</th>
                         <th>Required ?</th>
                         <th>Default Value</th>
                         <th>Description</th>
                     </tr>

                     <tr>
                         <td>resource-path</td>
                         <td>string</td>
                         <td>yes</td>
                         <td />
                         <td>The path to the script within the classpath.</td>
                     </tr>
                 </table>

             </subsection>

             <a name="script.initialization"></a>
             <subsection name="&lt;initialization&gt; element">


                 <p>
                     Appears in:
                     <a href="#script.script">&lt;script&gt;</a>
                 </p>

                 <p>
                     Allows a mix of text and control elements. This text is added to the large
                     scripting block just inside the HTML &lt;/body&gt; tag. It therefore can
                     refrence HTML objects within the page.
                 </p>

                 <p>&lt;initialization&gt; elements:</p>

                 <source xml:space="preserve">(<em>text</em> | <a href="#script.foreach">&lt;foreach&gt;</a> | <a
                         href="#script.if">&lt;if&gt;</a> | <a href="#script.if-not">&lt;if-not&gt;</a> | <a
                         href="#script.unique">&lt;unique&gt;</a>)*</source>
             </subsection>

 			<a name="script.input-symbol"></a>
             <subsection name="&lt;input-symbol&gt; element">


                 <p>
                     Appears in:
                     <a href="#script.script">&lt;script&gt;</a>
                 </p>

                 <p>
                     Defines an input symbol used by the script. Defining input symbols is optional;
                     it merely enforces that symbols be of a particular type, or enforces that a
                     non-null value be provided. This is handy as
                     <em>defensive programming</em>
                     .
                 </p>


                 <table>

                     <tr>
                         <th>Name</th>
                         <th>Type</th>
                         <th>Required ?</th>
                         <th>Default Value</th>
                         <th>Description</th>
                     </tr>

                     <tr>
                         <td>key</td>
                         <td>string</td>
                         <td>yes</td>
                         <td />
                         <td>The name of the symbol to check.</td>
                     </tr>

                     <tr>
                         <td>class</td>
                         <td>string</td>
                         <td>no</td>
                         <td />
                         <td>
                             If provided, then the actual value must be assignable to the given type
                             (which may be a Java class or interface name).
                         </td>
                     </tr>

                     <tr>
                         <td>required</td>
                         <td>boolean</td>
                         <td>no</td>
                         <td>no</td>
                         <td>If "yes", then a non-null value must be provided.</td>
                     </tr>
                 </table>

             </subsection>


 			<a name="script.let"></a>
             <subsection name="&lt;let&gt; element">


                 <p>
                     Appears in:
                     <a href="#script.script">&lt;script&gt;</a>
                 </p>

                 <p>
                     Defines a new symbol in terms of a string (usually with embedded expressions).
                 </p>

                 <p>
                     When a string is marked as unique, it is passed through a page-wide filter; if
                     the name conflicts with a previous unique string, then a numeric suffix is
                     appended to the string to ensure its uniqueness. This is most useful when
                     defining JavaScript client-side variables and functions, to ensure there are no
                     conflicts between different script templates, or successive executions of the
                     same script template.
                 </p>

                 <span class="info">
                     <strong>Note:</strong>
                     <p>
                         Starting with Tapestry 4.1.2, unique also ensures that the returned string can
                         be safely used as a javascript identifier (by replacing hyphens, colons and periods with
                         underscores).
                     </p>
                 </span>

                 <table>

                     <tr>
                         <th>Name</th>
                         <th>Type</th>
                         <th>Required ?</th>
                         <th>Default Value</th>
                         <th>Description</th>
                     </tr>

                     <tr>
                         <td>key</td>
                         <td>string</td>
                         <td>yes</td>
                         <td />
                         <td>The name of the new symbol to create.</td>
                     </tr>

                     <tr>
                         <td>unique</td>
                         <td>boolean</td>
                         <td>no</td>
                         <td>no</td>
                         <td>If yes, then the string is made unique.</td>
                     </tr>

                 </table>

                 <p>&lt;let&gt; Elements</p>

                 <source xml:space="preserve">(<em>text</em> | <a href="#script.foreach">&lt;foreach&gt;</a> | <a
                         href="#script.if">&lt;if&gt;</a> | <a href="#script.if-not">&lt;if-not&gt;</a> | <a
                         href="#script.unique">&lt;unique&gt;</a>)*</source>


             </subsection>

 			<a name="script.script"></a>
             <subsection name="&lt;script&gt; element">


                 <p>
                     <em>root element</em>
                 </p>

                 <p>
                     The &lt;script&gt; element is the root element of the document. It contains no
                     attributes.
                 </p>

                 <p>&lt;script&gt; Elements</p>
                 <source xml:space="preserve">
 (<a href="#script.include-script">&lt;include-script&gt;</a>*, <a href="#script.input-symbol">&lt;input-symbol&gt;</a>*, (<a
                         href="#script.let">&lt;let&gt;</a> | <a href="#script.set">&lt;set&gt;</a>)*, <a
                         href="#script.body">&lt;body&gt;</a>?, <a href="#script.initialization">&lt;initialization&gt;</a>?)
             </source>

             </subsection><!-- script -->

 			<a name="script.set"></a>
             <subsection name="&lt;set&gt; element">


                 <p>
                     Appears in:
                     <em>many</em>
                 </p>

                 <p>
                     Creates a new symbol, or overwrites an existing symbol, in terms of an
                     <a href="http://www.ognl.org">OGNL</a>
                     expression.
                 </p>

                 <table>

                     <tr>
                         <th>Name</th>
                         <th>Type</th>
                         <th>Required ?</th>
                         <th>Default Value</th>
                         <th>Description</th>
                     </tr>

                     <tr>
                         <td>key</td>
                         <td>string</td>
                         <td>yes</td>
                         <td />
                         <td>The key for the input symbol to be created (or overwritten).</td>
                     </tr>

                     <tr>
                         <td>expression</td>
                         <td>string</td>
                         <td>yes</td>
                         <td />
                         <td>
                             The
                             <a href="http://www.ognl.org">OGNL</a>
                             expression to evaluate and assign to the input symbol.
                         </td>
                     </tr>
                 </table>

             </subsection><!-- script.set -->

 			<a name="script.unique"></a>
             <subsection name="&lt;unique&gt; element">


                 <p>
                     Appears in:
                     <em>many</em>
                 </p>

                 <p>
                     Defines a block of text that is only rendered once per page. This is appropriate
                     to certain kinds of initialization code that should not be duplicated, even if
                     the same script template is executed multiple times.
                 </p>

                 <p>&lt;script&gt; elements:</p>

                 <source xml:space="preserve">(<em>text</em> | <a href="#script.foreach">&lt;foreach&gt;</a> | <a
                         href="#script.if">&lt;if&gt;</a> | <a href="#script.if-not">&lt;if-not&gt;</a> | <a
                         href="#script.unique">&lt;unique&gt;</a>)*</source>

             </subsection>

         </section>

     </body>
 </document>
	<?xml version="1.0" encoding="UTF-8"?>
	<!--
	Copyright 2005 The Apache Software Foundation

	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and
	limitations under the License.
	-->
	<document>
	<properties>
	<title>Script Template Specification DTDs</title>
	</properties>
	<body>

	<section name="Script Template Specification DTDs">
	<p>
	Script template specifications are the odd man out when it comes to Tapestry XML
	files as they don't use the same DTD as the
	<a href="spec.html">other specifications</a>
	.
	</p>

	<p>
	Script templates are used to dynamically generate JavaScript to support client-side
	behaviors associated with components. Tapestry is all about dynamically renderered,
	customized HTML, so it makes sense that dynamically rendered, customize JavaScript
	to complement that HTML should also be supported.
	</p>

	<p>
	Script template files are parsed into memory as instances of
	<a href="../apidocs/org/apache/tapestry/IScript.html">IScript</a>
	. These script template
	<em>objects</em>
	may be executed to generate the JavaScript.
	</p>

	<p>
	Many different script template objects may be executed during the course of
	rendering a page; all the JavaScript from all the executions are organized into two
	JavaScript blocks in the output page: the
	<em>main body</em>
	at the top of the page (just inside the HTML <body> tag), and an
	<em>initialization block</em>
	at the bottom of the page, (just before the HTML </body> tag).
	</p>

	<p>
	Executing a script template requires access to an
	<a href="../apidocs/org/apache/tapestry/IScriptProcessor.html">
	IScriptProcessor
	</a>
	instance; this is usually provided by the
	<a href="../components/general/body.html">Body</a>
	component. The script processor is responsible for managing the buffers of
	JavaScript, and assists with generating unique ids for client-side variables and
	functions.
	</p>

	<p>
	A script template works with
	<em>symbols</em>
	, a set of key/value pairs (implements as a Map). The script operates upon the input
	symbols and generates new output symbols along the way, while generating JavaScript.
	In some cases, the output symbols may be used by a component when rendering HTML.
	</p>

	<p>
	Many of the elements in a script template have a body of parsable character data. In
	the body of an element, you may reference symbols using the Ant-like ${...} syntax.
	I.e.
	<code>${name}</code>
	. In fact, the string inside the curly braces is an
	<a href="http://www.ognl.org">OGNL</a>
	expression, so you may create more complex expressions, such as
	<code>${field.form.name}</code>
	.
	</p>

	<subsection name="DOCTYPE">


	<p>The DOCTYPE for a script template specification is:</p>

	<source xml:space="preserve">
	<!DOCTYPE script PUBLIC
	"-//Apache Software Foundation//Tapestry Script Specification 3.0//EN"
	"http://jakarta.apache.org/tapestry/dtd/Script_3_0.dtd"></source>
	</subsection><!-- DOCTYPE -->

	<a name="script.body"></a>
	<subsection name="<body> element">


	<p>
	Appears in:
	<a href="#script.script"><script></a>
	</p>

	<p>
	Allows a mix of text and control elements. This text is added to the large
	scripting block just inside the HTML <body> tag.
	</p>

	<p><body> elements:</p>

	<source xml:space="preserve">(<em>text</em> \| <a href="#script.foreach"><foreach></a> \| <a
	href="#script.if"><if></a> \| <a href="#script.if-not"><if-not></a> \| <a
	href="#script.unique"><unique></a>)*</source>
	</subsection>

	<a name="script.foreach"></a>
	<subsection name="<foreach> element">


	<p>
	Appears in:
	<em>many</em>
	</p>

	<p>
	Iterates over a list of items; this is modeled after the For component. No
	iteration occurs if the value from the expression is null.
	</p>

	<table>

	<tr>
	<th>Name</th>
	<th>Type</th>
	<th>Required ?</th>
	<th>Default Value</th>
	<th>Description</th>
	</tr>

	<tr>
	<td>key</td>
	<td>string</td>
	<td>no</td>
	<td />
	<td>Defines the symbol into which each succesive value is stored.</td>
	</tr>

	<tr>
	<td>index</td>
	<td>string</td>
	<td>no</td>
	<td />
	<td>
	Defines the symbol into which the index of the value of the current
	iteration is stored.
	</td>
	</tr>

	<tr>
	<td>expression</td>
	<td>string</td>
	<td>yes</td>
	<td />
	<td>
	The source of values, as an OGNL expression rooted in the symbols Map.
	</td>
	</tr>
	</table>

	<p><foreach> elements:</p>

	<source xml:space="preserve">(<em>text</em> \| <a href="#script.foreach"><foreach></a> \| <a
	href="#script.if"><if></a> \| <a href="#script.if-not"><if-not></a> \| <a
	href="#script.unique"><unique></a>)*</source>
	</subsection>

	<a name="script.if"></a>
	<subsection name="<if> element">


	<p>
	Appears in:
	<em>many</em>
	</p>

	<p>
	Creates a conditional portion of the script; The body of the element is only
	included if the expression evaulates to true.
	</p>

	<table>

	<tr>
	<th>Name</th>
	<th>Type</th>
	<th>Required ?</th>
	<th>Default Value</th>
	<th>Description</th>
	</tr>

	<tr>
	<td>expression</td>
	<td>string</td>
	<td>yes</td>
	<td />
	<td>
	The
	<a href="http://www.ognl.org">OGNL</a>
	expression to evaluate.
	</td>
	</tr>


	</table>

	<p><if> Elements</p>

	<source xml:space="preserve">(<em>text</em> \| <a href="#script.foreach"><foreach></a> \| <a
	href="#script.if"><if></a> \| <a href="#script.if-not"><if-not></a> \| <a
	href="#script.unique"><unique></a>)*</source>

	</subsection>

	<a name="script.if-not"></a>
	<subsection name="<if-not> element">


	<p>
	Identical to the
	<a href="#script.if"><if></a>
	element, except that the body is only included in the output if the expression
	evaluates to
	<strong>false</strong>
	.
	</p>
	</subsection>


	<a name="script.include-script"></a>
	<subsection name="<include-script> element">


	<p>
	Inserts a reference to a static JavaScript file stored on the classpath. A
	particular file will only be included once per rendering of a page.
	</p>

	<p>
	For best performance, as much logic as possible should be shifted into static
	JavaScript library files that are included via this element. The dynamic portion
	of the JavaScript should really be initialization of code provided by such a
	static JavaScript library. This optimizes that amount of data that must be sent
	to the client web browser, as it will be able to cache the content of static
	library files.
	</p>

	<p>
	Appears in:
	<a href="#script.script"><script></a>
	</p>

	<table>

	<tr>
	<th>Name</th>
	<th>Type</th>
	<th>Required ?</th>
	<th>Default Value</th>
	<th>Description</th>
	</tr>

	<tr>
	<td>resource-path</td>
	<td>string</td>
	<td>yes</td>
	<td />
	<td>The path to the script within the classpath.</td>
	</tr>
	</table>

	</subsection>

	<a name="script.initialization"></a>
	<subsection name="<initialization> element">


	<p>
	Appears in:
	<a href="#script.script"><script></a>
	</p>

	<p>
	Allows a mix of text and control elements. This text is added to the large
	scripting block just inside the HTML </body> tag. It therefore can
	refrence HTML objects within the page.
	</p>

	<p><initialization> elements:</p>

	<source xml:space="preserve">(<em>text</em> \| <a href="#script.foreach"><foreach></a> \| <a
	href="#script.if"><if></a> \| <a href="#script.if-not"><if-not></a> \| <a
	href="#script.unique"><unique></a>)*</source>
	</subsection>

	<a name="script.input-symbol"></a>
	<subsection name="<input-symbol> element">


	<p>
	Appears in:
	<a href="#script.script"><script></a>
	</p>

	<p>
	Defines an input symbol used by the script. Defining input symbols is optional;
	it merely enforces that symbols be of a particular type, or enforces that a
	non-null value be provided. This is handy as
	<em>defensive programming</em>
	.
	</p>


	<table>

	<tr>
	<th>Name</th>
	<th>Type</th>
	<th>Required ?</th>
	<th>Default Value</th>
	<th>Description</th>
	</tr>

	<tr>
	<td>key</td>
	<td>string</td>
	<td>yes</td>
	<td />
	<td>The name of the symbol to check.</td>
	</tr>

	<tr>
	<td>class</td>
	<td>string</td>
	<td>no</td>
	<td />
	<td>
	If provided, then the actual value must be assignable to the given type
	(which may be a Java class or interface name).
	</td>
	</tr>

	<tr>
	<td>required</td>
	<td>boolean</td>
	<td>no</td>
	<td>no</td>
	<td>If "yes", then a non-null value must be provided.</td>
	</tr>
	</table>

	</subsection>


	<a name="script.let"></a>
	<subsection name="<let> element">


	<p>
	Appears in:
	<a href="#script.script"><script></a>
	</p>

	<p>
	Defines a new symbol in terms of a string (usually with embedded expressions).
	</p>

	<p>
	When a string is marked as unique, it is passed through a page-wide filter; if
	the name conflicts with a previous unique string, then a numeric suffix is
	appended to the string to ensure its uniqueness. This is most useful when
	defining JavaScript client-side variables and functions, to ensure there are no
	conflicts between different script templates, or successive executions of the
	same script template.
	</p>

	<span class="info">
	<strong>Note:</strong>
	<p>
	Starting with Tapestry 4.1.2, unique also ensures that the returned string can
	be safely used as a javascript identifier (by replacing hyphens, colons and periods with
	underscores).
	</p>
	</span>

	<table>

	<tr>
	<th>Name</th>
	<th>Type</th>
	<th>Required ?</th>
	<th>Default Value</th>
	<th>Description</th>
	</tr>

	<tr>
	<td>key</td>
	<td>string</td>
	<td>yes</td>
	<td />
	<td>The name of the new symbol to create.</td>
	</tr>

	<tr>
	<td>unique</td>
	<td>boolean</td>
	<td>no</td>
	<td>no</td>
	<td>If yes, then the string is made unique.</td>
	</tr>

	</table>

	<p><let> Elements</p>

	<source xml:space="preserve">(<em>text</em> \| <a href="#script.foreach"><foreach></a> \| <a
	href="#script.if"><if></a> \| <a href="#script.if-not"><if-not></a> \| <a
	href="#script.unique"><unique></a>)*</source>


	</subsection>

	<a name="script.script"></a>
	<subsection name="<script> element">


	<p>
	<em>root element</em>
	</p>

	<p>
	The <script> element is the root element of the document. It contains no
	attributes.
	</p>

	<p><script> Elements</p>
	<source xml:space="preserve">
	(<a href="#script.include-script"><include-script></a>, <a href="#script.input-symbol"><input-symbol></a>, (<a
	href="#script.let"><let></a> \| <a href="#script.set"><set></a>)*, <a
	href="#script.body"><body></a>?, <a href="#script.initialization"><initialization></a>?)
	</source>

	</subsection><!-- script -->

	<a name="script.set"></a>
	<subsection name="<set> element">


	<p>
	Appears in:
	<em>many</em>
	</p>

	<p>
	Creates a new symbol, or overwrites an existing symbol, in terms of an
	<a href="http://www.ognl.org">OGNL</a>
	expression.
	</p>

	<table>

	<tr>
	<th>Name</th>
	<th>Type</th>
	<th>Required ?</th>
	<th>Default Value</th>
	<th>Description</th>
	</tr>

	<tr>
	<td>key</td>
	<td>string</td>
	<td>yes</td>
	<td />
	<td>The key for the input symbol to be created (or overwritten).</td>
	</tr>

	<tr>
	<td>expression</td>
	<td>string</td>
	<td>yes</td>
	<td />
	<td>
	The
	<a href="http://www.ognl.org">OGNL</a>
	expression to evaluate and assign to the input symbol.
	</td>
	</tr>
	</table>

	</subsection><!-- script.set -->

	<a name="script.unique"></a>
	<subsection name="<unique> element">


	<p>
	Appears in:
	<em>many</em>
	</p>

	<p>
	Defines a block of text that is only rendered once per page. This is appropriate
	to certain kinds of initialization code that should not be duplicated, even if
	the same script template is executed multiple times.
	</p>

	<p><script> elements:</p>

	<source xml:space="preserve">(<em>text</em> \| <a href="#script.foreach"><foreach></a> \| <a
	href="#script.if"><if></a> \| <a href="#script.if-not"><if-not></a> \| <a
	href="#script.unique"><unique></a>)*</source>

	</subsection>

	</section>

	</body>
	</document>