Author latest posts pagination - php

Question

I'm having difficulties in adding pagination for custom wordpress query showing latest author's posts from category 'blog'. I found this code somewhere on stackoverflow. Could someone help me/give some tips how to add pagination to this query? I've spent on it couple hours and couldn't came up with something working.
Best for me would be numeric pagination:
1 | 2 | 3 | 4 | so on...
functions.php
function the_latest_author_posts($post) {
$relatedargs = array(
'author' => $post->post_author,
'post__not_in' => array( $post->ID),
'posts_per_page' => 8,
'category_name' => 'blog',
);
$relatedquery = new WP_Query( $relatedargs );
while($relatedquery->have_posts()){
$relatedquery->the_post();
$ID = get_the_ID();
?>
<div class="post-blog">
<?php
if(has_post_thumbnail()) {
$relatedthumbnail = wp_get_attachment_image_src( get_post_thumbnail_id($ID), 'medium', false);
$relatedthumbnail_large = wp_get_attachment_image_src( get_post_thumbnail_id($ID), 'full', false);
?>
<?php } ?>
<h1><span><?php the_title(); ?></span></h1>
<h6><i class="fa fa-clock-o" aria-hidden="true"></i> <?php echo get_the_time('j') . '/' . get_the_time('m') . '/' . get_the_time('Y') . ' '; ?></h6>
<?php
$content = get_the_content();
echo wp_trim_words( $content , '25' ); ?>
</div>
<?php wp_reset_postdata();}}
I call this function in my template in this way:
<?php
if ( have_posts() ) {
while ( have_posts() ) {
the_post();
the_latest_author_posts($post);
}
}
?>

Answer 1

First add this function in your functions
function numeric_pagination($pages = '', $range = 2){
$showitems = ($range * 2)+1;
global $paged;
if(empty($paged)) $paged = 1;
if($pages == '')
{
global $wp_query;
$pages = $wp_query->max_num_pages;
if(!$pages)
{
$pages = 1;
}
}
if(1 != $pages)
{
echo "<div class='pagination'>";
if($paged > 2 && $paged > $range+1 && $showitems < $pages) echo "<a href='".get_pagenum_link(1)."'>«</a>";
if($paged > 1 && $showitems < $pages) echo "<a href='".get_pagenum_link($paged - 1)."'>‹</a>";
for ($i=1; $i <= $pages; $i++)
{
if (1 != $pages &&( !($i >= $paged+$range+1 || $i <= $paged-$range-1) || $pages <= $showitems ))
{
echo ($paged == $i)? "<span class='current'>".$i."</span>":"<a href='".get_pagenum_link($i)."' class='inactive' >".$i."</a>";
}
}
if ($paged < $pages && $showitems < $pages) echo "<a href='".get_pagenum_link($paged + 1)."'>›</a>";
if ($paged < $pages-1 && $paged+$range-1 < $pages && $showitems < $pages) echo "<a href='".get_pagenum_link($pages)."'>»</a>";
echo "</div>\n";
} }
and use it after your loop
numeric_pagination();