Wordpress Custom Query with Custom Taxonomies - Pagination Bug

I've created a custom query with multiple taxonomies involved, and on top of that I use paginate_links to have pagination in place. Taxonomies are being selected by drop-down select forms using onchange="this.form.submit()" to be able to filter posts and which is only a temporary solution but works fine for now, and worth noting for the sake of this case.

Pagination works fine, posts are being displayed correctly when taxonomy terms selected, however when I leave the first page and let's say I go to page #2 and I select a different taxonomy-term in the drop-down selector, the URL keeps the current page number, and adds the selector ID to it. Whereas what I would like to achive is when I click on a different taxonomy in the selector, the newly selected taxonomy query creates a new URL to start from the first page of that certain taxonomy.

Let me bring up an example to be more clear of what I mean above:

1. I select taxonomy term "brand1" from the brand selector to display all posts related to that taxonomy term

URL at this point is mydomainname.com/?brandselector=brand1 and so far so good.

2. I go to page number #2 via the pagination, now the URL looks like this:
   mydomainname.com/page/2/?brandselector=brand1

3. The issue itself starts here: I click on a different taxonomy-term in any of the drop down selectors as shown below:

Now I either get an empty page if the taxonomy-term doesn't have enough posts to reach multiple pages of pagination, or I see lists of posts right from page 2 or whichever else number I was on before, of the newly selected taxonomy term.

URL now looks like this: mydomainname.com/page/2/?brandselector=brand2

So the page number is not being reset on a newly selected taxonomy-term.

My code:

    global $wpdb, $post, $page;            echo "<div class='entry-content'>";            echo '<div class="filter-box">';            echo '<form name="selectbrand" method="GET" style="width:200px;">';      echo '<select id="brandselector" name="brandselector" onchange="this.form.submit()">';        echo '<option value="">Select brand:</option>';          $brands = get_terms(array(                          'taxonomy' => 'brand',                          'hide_empty' => true,                          'orderby' => 'name',                      ) );               foreach ( $brands as $brand ) { ?>      <?php echo '<option value="' . $brand->slug . '">' . $brand->name . '</option>';              };              echo '</select>';              echo '</form>';            echo '<form name="selectdrive" method="GET" style="width:200px;">';      echo '<select id="driveselector" name="driveselector" onchange="this.form.submit()">';        echo '<option value="">Select drive:</option>';          $drives = get_terms(array(                          'taxonomy' => 'drive_cat',                          'hide_empty' => true,                          'orderby' => 'name',                      ) );               foreach ( $drives as $drive ) { ?>      <?php echo '<option value="' . $drive->slug . '">' . $drive->name . '</option>';              };              echo '</select>';              echo '</form>';                    echo '</div>'; //filter-box                  if ( !empty( $_GET['driveselector'])){          $term_id = $_GET['driveselector'];          }                  if ( !empty( $_GET['brandselector'])){          $term_id = $_GET['brandselector'];          }              //<-----------------<<<<Main Query start>>>>---------------------                  $main_args = array(                  'post_type'=> 'things',                  'orderby' => 'date',                  'order'   => 'DESC',                  'posts_per_page' => 5,                  'paged' => $page,      );             //<-----------------<<<<Main Query + Custom Query>>>>---------------------            $taxquery = array();            if ( !empty($term_id) || isset($term_id) ) {          array_push($taxquery,array(              'relation' => 'OR',              array(                  'taxonomy' => 'brand',                  'field' => 'slug',                  'terms' => $term_id                  ),              array(                  'taxonomy' => 'drive_cat',                  'field' => 'slug',                  'terms' => $term_id                  )              ));      }            if(!empty($taxquery)){          $main_args['tax_query'] = $taxquery;      }            global $main_query;      $main_query = new WP_Query( $main_args );    '<div class="content-box">';      if ( $main_query->have_posts() ) :     while ( $main_query->have_posts() ) : $main_query->the_post();      //content start here  

And the pagination:

//<!-- end blog posts -->    endwhile;    echo '<div class="pagination">';  $total_pages = $main_query->max_num_pages;  if ($total_pages > 1){      $current_page = max(1, get_query_var('page'));         echo paginate_links(array(              'base' => preg_replace('/\?.*/', '/', get_pagenum_link(1)) . '%_%',              'current' => $current_page,              'total' => $total_pages,              'prev_text'    => __('« prev'),              'next_text'    => __('next »'),          ));  }      echo '</div>';    wp_reset_postdata();    endif;  

What do I missing to reset URL when clicked on a different taxonomy-term? Any suggestions would be highly appreciated, and sorry if I used certain technical terms wrong, I'm still learning. Thanks.

https://stackoverflow.com/questions/67360188/wordpress-custom-query-with-custom-taxonomies-pagination-bug May 03, 2021 at 03:05AM