Pagination for Category does not work

Question

I am trying to implement pagination for category items listing archive.php page. But this does not work. Below is the code that I am using.

Custom Query:

$cat = single_cat_title("", false);
$cat_ID = get_cat_ID ($cat);

$args = array(
    'posts_per_page'    => '2',
    'post_type' => 'mathematics',
    'cat' => $cat_ID,
    'paged' => get_query_var('paged',1)
);
$posts = new WP_Query($args);

Pagination code:

echo paginate_links(array(
              'base'               => '%_%',
              'format'             => '?paged=%#%',
              'total' => $posts->max_num_pages,
              ));

When the page is loaded, it displays the pagination links but when I click on next it gives 404 error.

main page link: http://mk.local/category/mathematics/average/ when next is clicked : http://mk.local/category/mathematics/average/?paged=2

I have already tried updating permalinks

Answer 1

You should use the pre_get_posts action to get the correct number of category pages and links.
The complete solution is explained here.

Answer 2

Remove all your pagination and try something like this, where mytheme is the name of your theme

   <?php
$GLOBALS['wp_query']->max_num_pages = $custom_query->max_num_pages;
the_posts_pagination(array(
    'next_text' => '<span class="meta-nav" aria-hidden="true">' . __('Next Post', 'mytheme') . '</span> ' . '<span class="screen-reader-text">' . __('Next post:', 'mytheme') . '</span> <br/>' . '<span class="post-title">%title</span>',
    'prev_text' => '<span class="meta-nav" aria-hidden="true">' . __('Previous Post', 'mytheme') . '</span> ' . '<span class="screen-reader-text">' . __('Previous post:', 'mytheme') . '</span> <br/>' . '<span class="post-title">%title</span>'
));
?>

Let me know how it goes

Answer 3

This guy shows how to create AJAX pagination...

https://artisansweb.net/load-wordpress-post-ajax/

Very easy to follow, effective results.

Answer 4

1. $wp_query dump on page 1 (http://archive.local/category/mathematics/average)

   WP_Query Object ( [query] => Array ( [category_name] => mathematics/average ) [query_vars] => Array ( [category_name] => average [error] => [m] => [p] => 0 [post_parent] => [subpost] => [subpost_id] => [attachment] => [attachment_id] => 0 [name] => [static] => [pagename] => [page_id] => 0 [second] => [minute] => [hour] => [day] => 0 [monthnum] => 0 [year] => 0 [w] => 0 [tag] => [cat] => 6 [tag_id] => [author] => [author_name] => [feed] => [tb] => [paged] => 0 [meta_key] => [meta_value] => [preview] => [s] => [sentence] => [title] => [fields] => [menu_order] => [embed] => [category__in] => Array ( ) [category__not_in] => Array ( ) [category__and] => Array ( ) [post__in] => Array ( ) [post__not_in] => Array ( ) [post_name__in] => Array ( ) [tag__in] => Array ( ) [tag__not_in] => Array ( ) [tag__and] => Array ( ) [tag_slug__in] => Array ( ) [tag_slug__and] => Array ( ) [post_parent__in] => Array ( ) [post_parent__not_in] => Array ( ) [author__in] => Array ( ) [author__not_in] => Array ( ) [ignore_sticky_posts] => [suppress_filters] => [cache_results] => 1 [update_post_term_cache] => 1 [lazy_load_term_meta] => 1 [update_post_meta_cache] => 1 [post_type] => [posts_per_page] => 2 [nopaging] => [comments_per_page] => 50 [no_found_rows] => [order] => DESC ) [tax_query] => WP_Tax_Query Object ( [queries] => Array ( [0] => Array ( [taxonomy] => category [terms] => Array ( [0] => average ) [field] => slug [operator] => IN [include_children] => 1 ) ) [relation] => AND [table_aliases:protected] => Array ( [0] => wp_term_relationships ) [queried_terms] => Array ( [category] => Array ( [terms] => Array ( [0] => average ) [field] => slug ) ) [primary_table] => wp_posts [primary_id_column] => ID ) [meta_query] => WP_Meta_Query Object ( [queries] => Array ( ) [relation] => [meta_table] => [meta_id_column] => [primary_table] => [primary_id_column] => [table_aliases:protected] => Array ( ) [clauses:protected] => Array ( ) [has_or_relation:protected] => ) [date_query] => [queried_object] => WP_Term Object ( [term_id] => 6 [name] => Average [slug] => average [term_group] => 0 [term_taxonomy_id] => 6 [taxonomy] => category [description] => [parent] => 5 [count] => 6 [filter] => raw [cat_ID] => 6 [category_count] => 6 [category_description] => [cat_name] => Average [category_nicename] => average [category_parent] => 5 ) [queried_object_id] => 6 [request] => SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts LEFT JOIN wp_term_relationships ON (wp_posts.ID = wp_term_relationships.object_id) WHERE 1=1 AND ( wp_term_relationships.term_taxonomy_id IN (6) ) AND wp_posts.post_type = 'post' AND (wp_posts.post_status = 'publish') GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC LIMIT 0, 2 [posts] => Array ( ) [post_count] => 0 [current_post] => -1 [in_the_loop] => [comment_count] => 0 [current_comment] => -1 [found_posts] => 0 [max_num_pages] => 0 [max_num_comment_pages] => 0 [is_single] => [is_preview] => [is_page] => [is_archive] => 1 [is_date] => [is_year] => [is_month] => [is_day] => [is_time] => [is_author] => [is_category] => 1 [is_tag] => [is_tax] => [is_search] => [is_feed] => [is_comment_feed] => [is_trackback] => [is_home] => [is_privacy_policy] => [is_404] => [is_embed] => [is_paged] => [is_admin] => [is_attachment] => [is_singular] => [is_robots] => [is_posts_page] => [is_post_type_archive] => [query_vars_hash:WP_Query:private] => a661d92bb8a6ebd714003f1268022535 [query_vars_changed:WP_Query:private] => [thumbnails_cached] => [stopwords:WP_Query:private] => [compat_fields:WP_Query:private] => Array ( [0] => query_vars_hash [1] => query_vars_changed ) [compat_methods:WP_Query:private] => Array ( [0] => init_query_flags [1] => parse_tax_query ) )

2. $wp_query dump on page 2 (http://archive.local/category/mathematics/average/page/2/)

   WP_Query Object ( [query] => Array ( [paged] => 2 [category_name] => mathematics/average ) [query_vars] => Array ( [paged] => 2 [category_name] => average [error] => [m] => [p] => 0 [post_parent] => [subpost] => [subpost_id] => [attachment] => [attachment_id] => 0 [name] => [static] => [pagename] => [page_id] => 0 [second] => [minute] => [hour] => [day] => 0 [monthnum] => 0 [year] => 0 [w] => 0 [tag] => [cat] => 6 [tag_id] => [author] => [author_name] => [feed] => [tb] => [meta_key] => [meta_value] => [preview] => [s] => [sentence] => [title] => [fields] => [menu_order] => [embed] => [category__in] => Array ( ) [category__not_in] => Array ( ) [category__and] => Array ( ) [post__in] => Array ( ) [post__not_in] => Array ( ) [post_name__in] => Array ( ) [tag__in] => Array ( ) [tag__not_in] => Array ( ) [tag__and] => Array ( ) [tag_slug__in] => Array ( ) [tag_slug__and] => Array ( ) [post_parent__in] => Array ( ) [post_parent__not_in] => Array ( ) [author__in] => Array ( ) [author__not_in] => Array ( ) [ignore_sticky_posts] => [suppress_filters] => [cache_results] => 1 [update_post_term_cache] => 1 [lazy_load_term_meta] => 1 [update_post_meta_cache] => 1 [post_type] => [posts_per_page] => 2 [nopaging] => [comments_per_page] => 50 [no_found_rows] => [order] => DESC ) [tax_query] => WP_Tax_Query Object ( [queries] => Array ( [0] => Array ( [taxonomy] => category [terms] => Array ( [0] => average ) [field] => slug [operator] => IN [include_children] => 1 ) ) [relation] => AND [table_aliases:protected] => Array ( [0] => wp_term_relationships ) [queried_terms] => Array ( [category] => Array ( [terms] => Array ( [0] => average ) [field] => slug ) ) [primary_table] => wp_posts [primary_id_column] => ID ) [meta_query] => WP_Meta_Query Object ( [queries] => Array ( ) [relation] => [meta_table] => [meta_id_column] => [primary_table] => [primary_id_column] => [table_aliases:protected] => Array ( ) [clauses:protected] => Array ( ) [has_or_relation:protected] => ) [date_query] => [request] => SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts LEFT JOIN wp_term_relationships ON (wp_posts.ID = wp_term_relationships.object_id) WHERE 1=1 AND ( wp_term_relationships.term_taxonomy_id IN (6) ) AND wp_posts.post_type = 'post' AND (wp_posts.post_status = 'publish') GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC LIMIT 2, 2 [posts] => Array ( ) [post_count] => 0 [current_post] => -1 [in_the_loop] => [comment_count] => 0 [current_comment] => -1 [found_posts] => 0 [max_num_pages] => 0 [max_num_comment_pages] => 0 [is_single] => [is_preview] => [is_page] => [is_archive] => [is_date] => [is_year] => [is_month] => [is_day] => [is_time] => [is_author] => [is_category] => [is_tag] => [is_tax] => [is_search] => [is_feed] => [is_comment_feed] => [is_trackback] => [is_home] => [is_privacy_policy] => [is_404] => 1 [is_embed] => [is_paged] => [is_admin] => [is_attachment] => [is_singular] => [is_robots] => [is_posts_page] => [is_post_type_archive] => [query_vars_hash:WP_Query:private] => 6ff57f0f1abfeb2f58bbec696009b6bf [query_vars_changed:WP_Query:private] => [thumbnails_cached] => [stopwords:WP_Query:private] => [compat_fields:WP_Query:private] => Array ( [0] => query_vars_hash [1] => query_vars_changed ) [compat_methods:WP_Query:private] => Array ( [0] => init_query_flags [1] => parse_tax_query ) )

I don't understand why post_type is 'post'. I tried adding pre_get_posts filter like below.

function custom_query(){
    global $wp_query;
    $wp_query-> set('post_type', 'maths');
}
add_action('pre_get_posts', 'custom_query');

this changes the post_type to 'maths'. However the issue still remains unresolved.

I have recently started Wordpress development and feel totally lost with this issue :(

Edit: I just added 5 'posts' under 'Average' category and the pagination working. So, it seems that some how it is considering the max_num_pages from 'posts' for pagination and not from my custom post.

Answer 5

I added below code in functions.php and it is working fine now.

function custom_query( $query ){

    if(is_category()){
        $query->set( 'post_type', array( 'math' ) );
        $query->set( 'posts_per_page', '2' );
    }
}
add_action('pre_get_posts', 'custom_query');

Thank you all for your suggestions.

Answer 6

You need to set max page of your custom query to the global before the the_posts_pagination, like

$GLOBALS['wp_query']->max_num_pages = $query->max_num_pages;