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<h1 id="1601">Templates: Part II</h1>

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<h2 id="1602">Dynamic Content Tags</h2>

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Dynamic content tags are introduced as shortcuts to some commonly used <a href="?page=Configurations.Templates1#ct">component tags</a>. These tags are mainly used to render contents resulted from evaluating some PHP expressions or statements. They include <a href="#et">expression tags</a>, <a href="#st">statement tags</a>, <a href="#dt">databind tags</a>, <a href="#pt">parameter tags</a>, <a href="#at">asset tags</a> and <a href="#lot">localization tags</a>.

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<h3 id="1603">Expression Tags</h3>

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An expression tag represents a PHP expression that is evaluated when the template control is in <tt>PreRender</tt> stage. The expression evaluation result is inserted at the place where the tag resides in the template. The context (namely <tt>$this</tt>) of the expression is the control owning the template.

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The format of an expression tag is as follows,

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<com:TTextHighlighter Language="prado" CssClass="source block-content" id="code_190079">

<%= PhpExpression %>

</com:TTextHighlighter>

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For example, the following expression tag will display the current page title at the place,

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<com:TTextHighlighter Language="prado" CssClass="source block-content" id="code_190080">

<%= $this->Title %>

</com:TTextHighlighter>

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<h3 id="1604">Statement Tags</h3>

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Statement tags are similar to expression tags, except that statement tags contain PHP statements rather than expressions. The output of the PHP statements (using for example <tt>echo</tt> or <tt>print</tt> in PHP) are displayed at the place where the statement tag resides in the template. The context (namely <tt>$this</tt>) of the statements is the control owning the template. The format of statement tags is as follows,

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<com:TTextHighlighter Language="prado" CssClass="source block-content" id="code_190081">

<%%

PHP Statements

%>

</com:TTextHighlighter>

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The following example displays the current time in Dutch at the place,

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<com:TTextHighlighter Language="prado" CssClass="source block-content" id="code_190082">

<%%

setlocale(LC_ALL, 'nl_NL');

echo strftime("%A %e %B %Y",time());

%>

</com:TTextHighlighter>

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<h3 id="1605">Databind Tags</h3>

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Databind tags are similar to expression tags, except that the expressions are evaluated only when a <tt>dataBind()</tt> call is invoked on the controls representing the databind tags. The context (namely <tt>$this</tt>) of a databind expression is the control owning the template. The format of databind tags is as follows,

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<com:TTextHighlighter Language="prado" CssClass="source block-content" id="code_190083">

<%# PhpExpression %>

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<h3 id="1606">Parameter Tags</h3>

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Parameter tags are used to insert application parameters at the place where they appear in the template. The format of parameter tags is as follows,

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<com:TTextHighlighter Language="prado" CssClass="source block-content" id="code_190084">

<%$ ParameterName %>

</com:TTextHighlighter>

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Note, application parameters are usually defined in application configurations or page directory configurations. The parameters are evaluated when the template is instantiated.

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<h3 id="1607">Asset Tags</h3>

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Asset tags are used to publish private files and display the corresponding the URLs. For example, if you have an image file that is not Web-accessible and you want to make it visible to end-users, you can use asset tags to publish this file and show the URL to end-users so that they can fetch the published image.

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The format of asset tags is as follows,

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<com:TTextHighlighter Language="prado" CssClass="source block-content" id="code_190085">

<%~ LocalFileName %>

</com:TTextHighlighter>

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where <tt>LocalFileName</tt> refers to a file path that is relative to the directory containing the current template file. The file path can be a single file or a directory. If the latter, the content in the whole directory will be made accessible by end-users.

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BE VERY CAUTIOUS when you are using asset tags as it may expose to end-users files that you probably do not want them to see.

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<h3 id="1608">Localization Tags</h3>

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Localization tags represent localized texts. They are in the following format,

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<com:TTextHighlighter Language="prado" CssClass="source block-content" id="code_190086">

<%[string]%>

</com:TTextHighlighter>

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where <tt>string</tt> will be translated to different languages according to the end-user's language preference. Localization tags are in fact shortcuts to the function call <tt>Prado::localize(string)</tt>.

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<h3 id="1609">URL Tags</h3>

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URL tags are used to insert the relative web url path to the Prado application in the template. You can use it in the following format:

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<com:TTextHighlighter Language="prado" CssClass="source block-content" id="code_190087">

<%/ image.jpg %>

</com:TTextHighlighter>

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If your Prado application is deployed on http://localhost/pradoapp/, the tag above will produce "/pradoapp/image.jpg". This tag will help you to use the correct file path even with UrlFormat set to Path, or if you are using url mappings.

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<div class="last-modified">$Id: Templates2.page 2568 2008-11-13 11:27:44Z carlgmathisen $</div></com:TContent>