Categories List Walke wrapper function for WEN Team (AWPCP's Issue #833)

functions.php

<?php

function wen_shortcode_awpcp_list_categories( $atts ) {
  // unused
  extract( shortcode_atts( array(
    'type' => 'page',
    'value' => '1',
    'input' => 'id',
  ), $atts ) );

  if ( ! function_exists( 'awpcp_categories_collection' ) ) {
    return '';
  }

  if ( ! class_exists( 'WEN_CategoriesListWalker' ) ) {
    return '';
  }

  if ( ! class_exists( 'AWPCP_CategoriesRenderer' ) ) {
    return '';
  }

  $categories = awpcp_categories_collection();
  $walker = new WEN_CategoriesListWalker();
  $categories_renderer = new AWPCP_CategoriesRenderer( $categories, $walker );

  $categories_list = $categories_renderer->render( array( 'show_listings_count' => false ) );

  $output = '<div class="widget_nav_menu"><ul class="dropdown-menu">[categories-list]</ul></div>';
  $output = str_replace( '[categories-list]', $categories_list, $output );

  return $output;
}