Customise the WordPress gallery html layout

Question

I want change the WordPress gallery html layout, By default, the output of HTML is as follows:

             <div id="gallery-1" class="gallery galleryid-184 gallery-columns-3 gallery-size-thumbnail">
               <dl class="gallery-item">
                 <dt class="gallery-icon landscape">
                          <a href="http://localhost:8888/mmysite/tesla-2/"><img src="http://localhost:8888/mmysite/wp-content/uploads/2021/03/tesla.png" class="attachment-thumbnail size-thumbnail" alt="" loading="lazy" width="150" height="110"></a>
                     </dt>
               </dl>
               <dl class="gallery-item">
                      <dt class="gallery-icon landscape">
                          <a href="http://localhost:8888/mmysite/3/"><img src="http://localhost:8888/mmysite/wp-content/uploads/2021/03/3.gif" class="attachment-thumbnail size-thumbnail" alt="" loading="lazy" width="150" height="58"></a>
                      </dt>
               </dl>
                    <br style="clear: both">
                </div>

And I want change to this:

             <div class="mihan-gallery">
                 <a class="mihangitem" href="http://localhost:8888/mmysite/wp-content/uploads/2021/03/tesla.png"><img src="http://localhost:8888/mmysite/wp-content/uploads/2021/03/tesla.png" alt="" title=""/></a>
                 <a class="mihangitem" href="http://localhost:8888/mmysite/wp-content/uploads/2021/03/3.gif"><img src="http://localhost:8888/mmysite/wp-content/uploads/2021/03/3.gif" alt="" title=""/></a>
                 <div class="clear"></div>
             </div>

Answer 1

I find a solution for this:

// Customise the WordPress gallery html layout
add_filter('post_gallery','customFormatGallery',10,2);
function customFormatGallery($string,$attr){
    $output = "<div class=\"mihan-gallery\">";
    $posts = get_posts(array('include' => $attr['ids'],'post_type' => 'attachment'));
    foreach($posts as $imagePost){
        $output .= "<a class=\"mihangitem\" href='".wp_get_attachment_image_src($imagePost->ID, 'mihan-large')[0]."'><img src='".wp_get_attachment_image_src($imagePost->ID, 'mihan-medium')[0]."'></a>";
    }
    $output .= "<div class=\"clear\"></div></div>";
    return $output;
}