FireTree-Transient-Fallback for WordPress

Adds a fallback layer to the transient data that allows a background hook to update the transient without the end user having to wait.

How does it work?

When ->set_transient( $transient, $value, $expiration ) is called, two transients are set. One that expires at the time you specified and another that expires at the fallback_expiration that was set when the class was initialized.

When ->get_transient( $transient, $hook, $args ) is called, the transient is checked for data. If the transient has data, then it is returned, but if the transient has expired, then the $hook is scheduled using wp_schedule_single_event. The fallback transient is then checked for data. If the fallback transient has data, then it is returned, but if the fallback transient has expired, then false is returned. Meanwhile, the $hook is scheduled to run in the background to update both transients with new data.

Example of adding it to a Plugin

Add this to your main plugin file.

<?php
/**
 * Setup FireTree Transient Fallback
 */
require_once( plugin_dir_path( __FILE__ ) . 'includes/FireTree_Transient_Fallback.php' );
$ft_transient_fallback_args = array(
	'prefix'				=> 'ft_',	// Prefix to add to each transient
	'fallback_expiration'	=> 10080,	// In minutes. Defaults to 1 week.
	'cleanup'				=> true		// Activate hook to purge expired transients?
);
$ft_transient_fallback = new FireTree_Transient_Fallback( $ft_transient_fallback_args );
?>

Getting and Setting Transients

Getting a Transient

<?php
$ft_transient_fallback->get_transient( $transient, $hook, $args );
?>

$transient is the name of the transient.
$hook is the name of the hook to call if the transient has expired. The function that $hook references needs to be registered with add_action.
$args are the arguments to pass to the $hook.

Setting a Transient

<?php
$ft_transient_fallback->set_transient( $transient, $value, $expiration );
?>

$transient is the name of the transient.
$value is the transient value.
$expiration is how long you want the transient to live. In minutes.

License

The FireTree_Transient_Fallback class is licensed under the GPL v2 or later.