Streams allow you to use PHP streams as a template resource. The syntax is much the same a traditional template resource names.
Smarty will first look for a registered template resource. If nothing is found, it will check if a PHP stream is available. If a stream is available, Smarty will use it to fetch the template.
You can further define allowed streams with security enabled.
Example 237. Stream from PHP
Using a PHP stream for a template resource from the display() function.
Example 238. Stream from Template
Using a PHP stream for a template resource from within a template.