HomePHP Page 7 - Template-Based Web Development With patTemplate (part 2)
Setting Things Right - PHP
Got the basics down? Well, here's the advanced course - thisarticle demonstrates some of patTemplate's more sophisticated features,including the ability to dynamically show or hide templates, inheritvariables, use loops and conditional branches, and create dynamic,template-based forms and error handlers.
All the examples you've seen thus far have had their attributes set at design time. This is not very useful in the majority of the cases; most often, you'd prefer to alter attributes like the loop counter or the visibility at run time, on the basis of logic in your script.
Luckily, patTemplate knows this - and it allows you to accomplish this goal via the very cool setAttribute() method, which allows you to dynamically set template attributes on the fly. Consider the following example, which demonstrates:
<!-- index.tmpl -->
<patTemplate:tmpl name="index">
<html>
<head><basefont face="Arial"></head>
<body>
Hello, and welcome to my Web site!
<!-- blah blah -->
<patTemplate:link src="tip" />
</body>
</html>
</patTemplate:tmpl>
<patTemplate:tmpl name="tip" visibility="hidden">
<p><hr>
<font size="-1">New user tip: Use the Find box at the top right corner
of your screen to quickly search this site.</font> </patTemplate:tmpl>
As you can see, there are two templates in the file above;
the second one is initially hidden from view. However, I can turn it on in certain cases - such as, for example, when a user visits the site for the first time. Here's the script that takes care of this for me.
<?php
// alter this to see how the script functions
// when the variable is unset
$newUser = true;
// include the class
include("include/patTemplate.php");
// initialize an object of the class
$template = new patTemplate();
// set template location
$template->setBasedir("templates");
// add templates to the template engine
$template->readTemplatesFromFile("index.tmpl");
// turn tips on if new user
if ($newUser == true)
{
$template->setAttribute("tip", "visibility", "visible");
}
// parse and display template $template->displayParsedTemplate("index");
?>
Depending on the value of a particular variable, I can turn
the second template on or off, via a call to setAttribute().
You can use the setAttribute() method to manipulate other template attributes as well - try it with the "loop" or "varscope" attributes to see how it works.
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