Plugin files and functions must follow a very specific naming convention in order to be located by Smarty.
plugin files must be named as follows:
type.name.php
Where type is one of these plugin types:
And name should be a valid identifier; letters,
numbers, and underscores only, see
php variables.
Some examples: function.html_select_date.php,
resource.db.php,
modifier.spacify.php.
plugin functions inside the PHP files must be named as follows:
smarty_type, _name
The meanings of type and name are
the same as above.
An example modifier name foo would be function smarty_modifier_foo().
Smarty will output appropriate error messages if the plugin file it needs is not found, or if the file or the plugin function are named improperly.