class for create ajax load more button in wordpress

class_foxy_loadmore.php

<?php
class Loadmore_Button {
    public $article_wrapper = 'article-card';
    public $post_per_load = 6;
    public $button_text = 'Показать еще';
    public $button_loading_text = 'Загрузка...';
    public $button_data_attr = 'data-aos="fade-up"';
    public $orderby = 'date';
    public $article_class = '.all-news__item';
    public $button_class = 'all-news__btn-more';

    public function _construct($args) {
        //take arguments from attributes
        if (in_array('article_wrapper', $args))
            $this->article_wrapper = $args['article_wrapper'];
        if (in_array('post_per_load', $args))
            $this->post_per_load = $args['post_per_load'];
        if (in_array('button_text', $args))
            $this->button_text = $args['button_text'];
        if (in_array('button_loading_text', $args))
            $this->button_loading_text = $args['button_loading_text'];
        if (in_array('button_data_attr', $args))
            $this->button_data_attr = $args['button_data_attr'];
        if (in_array('article_class', $args))
            $this->article_class = $args['article_class'];
        if (in_array('button_class', $args))
            $this->button_class = $args['button_class'];

        //add actions wp
        add_action( 'wp_enqueue_scripts', array($this, 'enqueue_script'));
        add_action('wp_ajax_loadmore', array($this, 'ajax_handler'));
        add_action('wp_ajax_nopriv_loadmore', array($this, 'ajax_handler'));

        //init button
        $this->button_init();
    }
    private function get_template_name($wrapper) {
        $wrapper = str_split($this->article_wrapper, strripos($this->article_wrapper, '-'));
        $wrapper[1] = str_replace('-', '', $wrapper[1]);
        return $wrapper;
    }

    private function enqueue_script() {
        global $wp_query;
        wp_register_script( 'loadmore', get_stylesheet_directory_uri() . '/js/loadmore.js', array('jquery') );
        wp_localize_script( 'loadmore', 'loadmore_params', array(
            'ajaxurl' => site_url() . '/wp-admin/admin-ajax.php', // WordPress AJAX
            'posts' => json_encode( $wp_query->query_vars ), // посты
            'current_page' => get_query_var( 'paged' ) ? get_query_var('paged') : 2,
            'max_page' => $wp_query->max_num_pages,
            'all_posts' => $wp_query->found_posts,
            'category' => $wp_query->cat,
            'btn_text'  => $this->button_text,
            'btn_load_text' => $this->button_loading_text,
            'article_class' => $this->article_class,
        ));
        wp_enqueue_script( 'loadmore' );
    }

    private function ajax_handler() {
        // prepare our arguments for the query
        $args                   = json_decode( stripslashes( $_POST['query'] ), true );
        $wrapper                = $this->get_template_name($this->article_wrapper);
        $args['paged']          = $_POST['page'] + 1; // we need next page to be loaded
        $args['posts_per_page'] = $this->post_per_load;
        $args['orderby']        = $this->orderby;
        $args['offset']         = isset($_POST['offset']);
        query_posts( $args );
        if( have_posts() ) :
            while( have_posts() ): the_post(); ?>
                <?php get_template_part( $wrapper[0], $wrapper[1] ); ?>
            <?php
            endwhile;

        endif;
        die;
    }

    public function button_init() {
        global $wp_query;
        if ( $wp_query->max_num_pages > 1 ) {
            echo '<div class="loadmore-wrapper">
                    <button class="'. $this->button_class .' btn-more" ' . $this->button_data_attr. ' 
                            title="'.$this->button_text .'">
                       ' . $this->button_text . '
                    </button>
                 </div>';
        }
    }
}