MT | ET | Add a + iCal link to each ticket in the tickets email

tribe_add_ical_to_email.php

<?php

/**
 * Adds a + iCal link to each ticket in the tickets email
 *
 * @see tribe_tickets_ticket_email_ticket_bottom
 */
function tribe_add_ical_to_email( $order ) {
	// Temporarily change global post.
	$original_post = $GLOBALS['post'];
	$GLOBALS['post'] = get_post( $order['event_id'] );

	printf(
		'<a class="tribe-events-ical tribe-events-button" href="%1$s" title="%2$s">%3$s</a>',
		esc_url( tribe_get_single_ical_link() ),
		esc_attr__( 'Download .ics file', 'the-events-calendar' ),
		esc_html__( 'iCal Export', 'the-events-calendar' )
	);

	// Change post back.
	$GLOBALS['post'] = $original_post;
}
add_action ( 'tribe_tickets_ticket_email_ticket_bottom', 'tribe_add_ical_to_email', 101, 1 );