WordPress Transients Tutorial, Part 1

wordpress-transients-tutorial-01.php

<?php
/**
 * Get News posts.
 *
 * This is from a tutorial found here:
 * @link https://johnregan3.wordpress.com/how-to-improve-wordpress-load-times-using-transients
 *
 * @since 1.0.0
 * @uses jr3_news_query
 *
 * @return array Array of news posts, else an empty array.
 */
function jr3_get_news() {
	
	$output = get_transient( 'jr3_news' );
	
	/*
	 * Side note:
	 * When an empty array is possible
	 * (like if a stored array of posts is empty because
	 * none were found), don't do the typical "! empty()" check.
	 * 
	 * If the transient is not found, it will return false.
	 */
	if ( ( false !== $output ) && ( is_array( $output ) ) ) {
		
		// Return the array stored in the transient.
		return $output;
	}
	
	// Imaginary function to fetch data.
	$results = jr3_news_query();
	if ( is_array( $results ) ) {
		
		// Set our transient to expire in one hour.
		set_transient( 'jr3_news', $results, HOUR_IN_SECONDS );
		return $results;
	}
	
	// At a minimum, return an empty array.
	return array();
}