Question

Every time a tpl file is included the system first looks for a site-specific version of the file and falls back to a standard one if the site specific one does not exist. So perahps I put include “customer/main/test1.tpl”. If our site is google, the system would first look for “customer/main/google_test1.tpl” and fall back to “customer/main/test1.tpl” if that file doesn’t exist.

Note: Smarty 2.6.x

Answer 1

Did you know about the built-in template directory cascade? addTemplateDir and setTemplateDir allow you to specify multiple directories:

$smarty->setTemplateDir(array(
  'google' => 'my-templates/google/',
  'default' => 'my-templates/default/',
));

$smarty->display('foobar.tpl');

Smarty will first try to find my-templates/google/foobar.tpl, if not found try my-templates/default/foobar.tpl. Using this, you can build a complete templating cascade.

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That won’t be too helpful if you have lots of elements on the same cascade-level. Say you had specific templates for google, yahoo and bing besides your default.tpl. A solution could involve the default template handler function. Whenever Smarty comes across a template it can’t find, this callback is executed as a measure of last resort. It allows you to specify a template file (or template resource) to use as a fallback.

So you could {include}, {extend}, ->fetch(), ->display() site_google.tpl. If the file exists, everything is fine. If it doesn’t, your callback could replace _google with _default to fallback to the default template.

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If neither template_dir cascade nor default template handler function seems applicable, you’ll want to dig into custom template resources.