INTRODUCTION
This page describes how to attach custom processing handlers on the Plift template engine.
WHAT IS A HANDLER?
Besides the data interpolation feature, the Plift engine has just one core funcionality that is to search the HTML document using registered xpath expressions and triggering the associated subroutines.
A handler is just a perl subroutine bound to a xpath expression, usualy targgeting a element or attribute (like <x-include> or data-plift-include).
The following example attaches a handler to the HTML <head> element:
$plift->add_handler({
name => 'head_example',
tag => 'head',
handler => sub {
my ($head_element, $context) = @_;
# do you custom processing on the <head> element:
# - add SEO metadata?
# - process asset files?
# - add tracking code?
}
});I encourage you to read the source of the builtin handlers. They a very simple, just a few lines of code.