Custom page/post pagination navigation.

numeric_posts_nav.php

<?php

/**
 * numeric_posts_nav
 * Custom numeric page links.
 *
 * @method numeric_posts_nav
 *
 * @author Peter Wegren <peter @ paper-leaf.com>
 *
 * @param [query object] $custom_query [if not paginating for default WP_Query, pass in custom query object to paginate properly]
 *
 * @return [null] [prints/echos the prev/next and numeric page links]
 */
function numeric_posts_nav($custom_query = null) {
    if ( is_singular() ) {
        return;
    }

    global $wp_query;

    if ( $custom_query != null ) {
        // store global $wp_query so that get_previous_posts_link() and get_next_posts_link() work properly
        $default_query = $wp_query;
        $wp_query = $custom_query;

        $current_query = $custom_query;
    } else {
        $current_query = $wp_query;
    }

    /* Stop execution if there's only 1 page */
    if ( $current_query->max_num_pages <= 1 ) {
        return;
    }

    $paged = get_query_var('paged') ? absint(get_query_var('paged')) : 1;
    $max = intval($wp_query->max_num_pages);
    $li_count = 0;

    /*  Add current page to the array */
    if ( $paged >= 1 ) {
        $links[] = $paged;
    }

    /*  Add the pages around the current page to the array */
    if ( $paged >= 4 ) {
        $links[] = $paged - 1;
        $links[] = $paged - 2;
        $links[] = $paged - 3;
    }

    if ( ($paged + 4) <= $max ) {
        $links[] = $paged + 3;
        $links[] = $paged + 2;
        $links[] = $paged + 1;
    }

    if ( ($paged == 3) || ($paged == 6) ) {
        $links[] = 2;
    }

    echo '<nav class="pagination"><ul>'."\n";

    /*  Previous Post Link */
    if ( get_previous_posts_link() ) {
        printf('<li class="prev">%s</li>'."\n", get_previous_posts_link('<i class="fa fa-angle-left" aria-hidden="true"></i> Prev'));
    } else {
        printf('<li class="prev inactive">%s</li>'."\n", '<span><i class="fa fa-angle-left" aria-hidden="true"></i> Prev</span>');
    }

    /*  Link to first 9 pages if current page is not one of the 'middle' links */
    if ( $paged <= 9 ) {
        $i = 1;
        while ( (($paged + $i) <= 9) && (($paged + $i) <= $max) ) {
            $links[] = $paged + $i;
            ++$i;
        }
    }

    /*  Link to last 9 pages if current page is not one of the 'middle' links */
    if ( ($paged >= ($max - 5)) && (($max - 5) >= 1) ) {
        $i = $max - min(array(8, $max - 1));

        while ($i <= $max) {
            $links[] = $i;
            ++$i;
        }
    }

    /*  Link to first page, plus ellipses if necessary */
    if ( !in_array(1, $links) ) {
        $class = 1 == $paged ? ' class="active"' : '';

        printf('<li%s><a href="%s">%s</a></li>'."\n", $class, esc_url(get_pagenum_link(1)), '1');
        ++$li_count;

        if ( !in_array(2, $links) ) {
            echo '<li><span>&#8230;</span></li>';
            ++$li_count;
        }
    }

    /*  Link to current page, plus pages in either direction if necessary */
    sort($links);
    $links = array_unique($links);
    foreach ( $links as $link ) {
        $class = $paged == $link ? ' class="active"' : '';
        printf('<li%s><a href="%s">%s</a></li>'."\n", $class, esc_url(get_pagenum_link($link)), $link);
        ++$li_count;
    }

    /*  Link to last page, plus ellipses if necessary */
    if ( !in_array($max, $links) ) {
        if ( !in_array($max - 1, $links) ) {
            echo '<li><span>&#8230;</span></li>'."\n";
            ++$li_count;
        }

        $class = $paged == $max ? ' class="active"' : '';
        printf('<li%s><a href="%s">%s</a></li>'."\n", $class, esc_url(get_pagenum_link($max)), $max);
        ++$li_count;
    }

    /*  Next Post Link */
    if ( get_next_posts_link() ) {
        printf('<li class="next">%s</li>'."\n", get_next_posts_link('Next <i class="fa fa-angle-right" aria-hidden="true"></i>'));
    } else {
        printf('<li class="next inactive">%s</li>'."\n", '<span>Next <i class="fa fa-angle-right" aria-hidden="true"></i></span>');
    }

    echo '</ul></nav>'."\n";

    // reset global $wp_query
    if ($custom_query != null) {
        $wp_query = $default_query;
    }
}