WordPress sidebar widget for Review custom post type

review-sidebar.php

<?php
/*
Plugin Name: Review Types Sidebar Widget
Plugin URI: http://wanderlusting.me/dia
Description: Describe what your plugin does and why you created it.
Version: 1.0
Author: Arthur Kho
Author URI: https://github.com/islandjoe
*/

// Creating the widget 
class ReviewTypes_Widget extends WP_Widget {

  function __construct() {
    parent::__construct(
    // Base ID of your widget
    'reviewtypes_widget', 
    
    // Widget name will appear in UI
    __('Review Types Widget', 'wpme-lifeph'), 
    
    // Widget description
    array( 'description' => __( 'Display the review types', 'wpme-lifeph' ), ) 
    );
  }
  
  // Creating widget front-end
  // This is where the action happens
  public function widget( $args, $instance ) {
    $title = apply_filters( 'widget_title', $instance['title'] );
    // before and after widget arguments are defined by themes
    echo $args['before_widget'];
    
    if ( ! empty( $title ) )
      echo $args['before_title'] . $title . $args['after_title'];
    
    // This is where you run the code and display the output
    $args = [
    	'orderby'            => 'name',
    	'order'              => 'ASC',
    	'style'              => 'list',
    	'show_count'         => 0,
    	'hide_empty'         => 1,
    	'use_desc_for_title' => 0,
    	'child_of'           => 0,
    	'feed'               => '',
    	'feed_type'          => '',
    	'feed_image'         => '',
    	'exclude'            => '',
    	'exclude_tree'       => '',
    	'include'            => '',
    	'hierarchical'       => 0,
    	'title_li'           => __( '' ),
    	'show_option_none'   => __( 'No reviews' ),
    	'number'             => null,
    	'echo'               => 1,
    	'depth'              => 0,
    	'current_category'   => 0,
    	'pad_counts'         => 0,
    	'taxonomy'           => 'review-type',
    	'walker'             => null ];
    echo '<ul>';
    wp_list_categories( $args );
    echo '</ul>';
    
    echo "</aside>";
  }
    
  // Widget Backend 
  public function form( $instance ) {
    if ( isset( $instance[ 'title' ] ) ) {
      $title = $instance[ 'title'];
    }
    else {
      $title = __( 'New title', 'wpme-lifeph' );
    }
  // Widget admin form
  ?>
  <p>
  <label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title:' ); ?></label> 
  <input class="widefat" id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" type="text" value="<?php echo esc_attr( $title ); ?>" />
  </p>
  <?php 
  }
  	
  // Updating widget replacing old instances with new
  public function update( $new_instance, $old_instance ) {
  $instance = array();
  $instance['title'] = ( ! empty( $new_instance['title'] ) ) ? strip_tags( $new_instance['title'] ) : '';
  return $instance;
  }
} // Class wpb_widget ends here

// Register and load the widget
function wpb_load_widget() {
 register_widget( 'reviewtypes_widget' );
}
add_action( 'widgets_init', 'wpb_load_widget' );