Cache Metro Pro homepage with Transients API

front-page.php

<?php
//* Do NOT include the opening php tag shown above. Only modified code shown below.

function metro_homepage_widgets() {

	// get the transient
	$metro_homepage_content = get_transient( 'metro_homepage_content' );
	
	// check if homepage content exists
	if ( false === $metro_homepage_content ) :
	
		// homepage content doesn't exist, so generate the content now
	
		// start the output buffer 
		ob_start();	
		
			// output the widgets 
			genesis_widget_area( 'home-top', array(
				'before' => '<div class="home-top widget-area">',
				'after'  => '</div>',
			) );
			
			if ( is_active_sidebar( 'home-middle-left' ) || is_active_sidebar( 'home-middle-right' ) ) {
		
				echo '<div class="home-middle">';
		
				genesis_widget_area( 'home-middle-left', array(
					'before' => '<div class="home-middle-left widget-area">',
					'after'  => '</div>',
				) );
		
				genesis_widget_area( 'home-middle-right', array(
					'before' => '<div class="home-middle-right widget-area">',
					'after'  => '</div>',
				) );
		
				echo '</div>';
			
			}
		
			genesis_widget_area( 'home-bottom', array(
				'before' => '<div class="home-bottom widget-area">',
				'after'  => '</div>',
			) );

		// save homepage content as $metro_homepage_content
        $metro_homepage_content = ob_get_contents();
		
		// empty buffer and stop output buffering
		ob_end_clean();
		
		// save transient to last for 12 hours
		set_transient('metro_homepage_content', $metro_homepage_content, 12 * HOUR_IN_SECONDS );
		
	endif;

	// output the new created fragment if transient does not exist. 
	echo $metro_homepage_content;
	
}

genesis();

functions.php

<?php
//* Do NOT include the opening php tag shown above. Only modified code shown below.

//* Delete metro_homepage_content transient
function metro_delete_homepage_transient() {
	delete_transient( 'metro_homepage_content' );
}
add_action( 'save_post', 'metro_delete_homepage_transient' );		// delete transient when saving posts
add_action( 'deleted_post', 'metro_delete_homepage_transient' );	// delete transient when deleting posts
add_action( 'update_option', 'metro_delete_homepage_transient' );	// delete transient when any WP settings are saved
// add_action( 'update_option_sidebars_widgets', 'metro_delete_homepage_transient' );		// when widgets are repositioned
// add_action( 'update_option_widget_featured-post', 'metro_delete_homepage_transient' );	// when Featured Post widget settings saved