Template override for list/nav.php (TEC 3.8.x) - tests possible efficiency savings in list view pagination

nav.php

<?php
/**
 * List view nav template (making use of alternative pagination functions)
 *
 * This template isn't really the proper place for the two template definitions included
 * at the top, but they could easily be moved to a more suitable location. They've been
 * included in this file for no reason other than ease of demonstrating and sharing a
 * workaround.
 */
defined( 'ABSPATH' ) or exit( '-1' );


if ( ! function_exists( 'tribe_are_there_previous_events' ) ) {
	/**
	 * Try to determine if there are previous events we need to link to.
	 *
	 * @return bool
	 */
	function tribe_are_there_previous_events() {
		global $wp_query;

		$upcoming  = tribe_is_upcoming();
		$past      = ! $upcoming;
		$cur_page  = (int) $wp_query->get( 'paged' );
		$max_pages = (int) $wp_query->max_num_pages;
		$page_1    = 0 === $cur_page || 1 === $cur_page;

		// Simple tests based on pagination properties
		if ( $upcoming && $cur_page > 1 ) return true;
		if ( $past && $cur_page < $max_pages ) return true;

		// Test for past events (on first page of upcoming list only)
		if ( $upcoming && $page_1 ) {
			$args = (array) $wp_query->query;
			$args['eventDisplay']   = 'past';
			$args['no_paging']      = true;
			$args['no_found_rows']  = true;
			$args['posts_per_page'] = 1;

			$past_events = tribe_get_events( $args );
			return ( count( $past_events ) >= 1 );
		}

		// Undetermined
		return false;
	}
}

if ( ! function_exists( 'tribe_are_there_more_events' ) ) {
	/**
	 * Try to determine if there are more events to page forward into.
	 *
	 * @return bool
	 */
	function tribe_are_there_more_events() {
		global $wp_query;

		$upcoming  = tribe_is_upcoming();
		$past      = ! $upcoming;
		$cur_page  = (int) $wp_query->get( 'paged' );
		$max_pages = (int) $wp_query->max_num_pages;
		$page_1    = 0 === $cur_page || 1 === $cur_page;

		// Simple tests based on pagination properties
		if ( $upcoming && $cur_page < $max_pages ) return true;
		if ( $past && $cur_page > 1 ) return true;

		// Test for future events (on first page of the past events list only)
		if ( $past && $page_1 ) {
			$args = (array) $wp_query->query;
			$args['eventDisplay']   = 'list';
			$args['no_paging']      = true;
			$args['no_found_rows']  = true;
			$args['posts_per_page'] = 1;

			$upcoming_events = tribe_get_events( $args );
			return ( count( $upcoming_events ) >= 1 );
		}

		// Undetermined
		return false;
	}
}
?>

<h3 class="tribe-events-visuallyhidden"><?php _e( 'Events List Navigation', 'tribe-events-calendar' ) ?></h3>
<ul class="tribe-events-sub-nav">
	<!-- Left Navigation -->

	<?php if ( tribe_are_there_previous_events() ) : ?>
		<li class="<?php echo tribe_left_navigation_classes(); ?>">
			<a href="<?php echo tribe_get_listview_link() ?>" rel="prev"><?php _e( '<span>&laquo;</span> Previous Events', 'tribe-events-calendar' ) ?></a>
		</li><!-- .tribe-events-nav-left -->
	<?php endif; ?>

	<!-- Right Navigation -->
	<?php if ( function_exists( 'tribe_are_there_more_events' ) && tribe_are_there_more_events() ) : ?>
		<li class="<?php echo tribe_right_navigation_classes(); ?>">
			<a href="<?php echo tribe_get_listview_link() ?>" rel="next"><?php _e( 'Next Events <span>&raquo;</span>', 'tribe-events-calendar' ) ?></a>
		</li><!-- .tribe-events-nav-right -->
	<?php endif; ?>
</ul>