WordPress pagination not working on custom post types and taxonomy terms

Question

Trying to paginate custom post types by custom taxonomy terms and default posts by category but it does not working. I'm novice to WordPress, I did lots of googling and didn't find a detailed solution to solve my issue.

If anyone knows please share your answer, it's really appreciated.

Note: I created a custom theme.

Here is my taxonomy-product_category.php page code:

<?php get_header();?>

<div class="container-fluid pages">
 <div class="container" style="margin-top: 10%;">
  <div class="row">
    <div class="col-sm-8">
        <div class="panel panel-default">
            <?php $term = get_queried_object();
            $taxonomy = get_taxonomy($term->taxonomy);

            ?>
            <div class="panel-heading"><h4><?php echo 'محصولات : '.$term-  >name;?></h4></div>
            <div class="panel-body">
                <?php

                $paged = ( get_query_var('paged') ) ? get_query_var('paged') : 1;
                    $args = array('post_type'=>'my_product',
                        'taxonomy'=>$taxonomy->name,
                        'posts_per_page'=> 1,
                        'term'=>$term->slug,
                        'paged'=>$paged);

                    $query = new WP_Query($args);
                if ($query->have_posts()) {
                    while ($query->have_posts()): $query->the_post(); ?>
                        <div class="thumbnail">
                            <?php if (has_post_thumbnail()) {
                                the_post_thumbnail('featured');
                            } ?>
                            <div class="caption caption-content">
                                <h3 class="product-name"><?php the_title();  ?></h3>
                                <p class="text-muted">
                                    <!-- <strong>نویسنده:</strong> <?php     //the_author();?>  -->
                                    &nbsp;&nbsp; تاریخ: <?php the_date(); ?> </p>
                                <p> <?php the_excerpt(); ?> </p>
                                <div>
                                    <p class="price-box">
                                        <i class="fa fa-  circle">&nbsp;&nbsp;&nbsp;</i>قیمت:
                                        <?php if (the_field('price') == '')     {
                                            // echo "00.00";
                                        } else {
                                            the_field('price');
                                        } ?>
                                    </p>

                                </div>
                            </div>
                            <hr>
                        </div>
                    <?php endwhile;
                }
                else {
                    echo '<h3>هیچ موردی درین بخش یافت نشد.</h3>';
                }
                ?>

                <!-- pagination here -->
                <p>

                        <nav>
                            <?php if ( function_exists( 'custom_pagination'   ) ) {
                                custom_pagination($custom_query-  >max_num_pages,"", $paged);
                            } ?>
                        </nav>

                <?php wp_reset_postdata(); ?>
                </p>

            </div>

        </div>
    </div>
        <?php get_sidebar();  ?>

 </div>
</div>
</div>
<?php get_footer();?>

When I click on next page it redirects me to index page where the url is still: http://localhost/goldsotre/product_category/ring/page/2/ Custom_pagination function:

function custom_pagination($numpages = '', $pagerange = '', $paged='') {

if (empty($pagerange)) {
    $pagerange = 2;
}
global $paged;
if (empty($paged)) {
    $paged = 1;
}
if ($numpages == '') {
    global $wp_query;
    $numpages = $wp_query->max_num_pages;
    if(!$numpages) {
        $numpages = 1;
    }
}
$pagination_args = array(
    'base'            => get_pagenum_link(1) . '%_%',
    'format'          => 'page/%#%',
    'total'           => $numpages,
    'current'         => $paged,
    'show_all'        => False,
    'end_size'        => 1,
    'mid_size'        => $pagerange,
    'prev_next'       => True,
    'prev_text'       => __('«'),
    'next_text'       => __('»'),
    'type'            => 'plain',
    'add_args'        => false,
    'add_fragment'    => ''
);

$paginate_links = paginate_links($pagination_args);

if ($paginate_links) {
    echo "<nav class='custom-pagination'>";
    echo "<span class='page-numbers page-num'>Page " . $paged . " of " . $numpages . "</span> ";
    echo $paginate_links;
    echo "</nav>";
}

Answer 1

Chance is posts_per_page got overridden by Blog pages show at most value.

I assume you're using the paginate_link() function, try this in functions.php:

add_action('pre_get_posts', function($query)
{
    if ($query->is_tax('product_category')) {
        $query->set('posts_per_page', 1);
    }
});

Make sure product_category is the taxonomy of the archive page. This article maybe helpful for you.

Answer 2

If I use below function instead of that I can see the pagination links but not working, when clicking on the next link, I get 404 page.

$big = 999999999; 
echo paginate_links( array(
'base' => str_replace( $big, '%#%', esc_url( get_pagenum_link( $big ) ) ),
'format' => '?paged=%#%',
'current' => max( 1, get_query_var('paged') ),
'total' => $query->max_num_pages ) );