Wordpress Shortcode for links in MODx similar style

wp_link_shortcode.php

<?php
public function generate_wp_link($atts)
{
  $atts = shortcode_atts( array(
			'id' => false,
      'text' => false,
      'modal' => false,
		), $atts, '~' );

  list($key, $value) = explode(':', $atts['id']);

  if(is_numeric($atts['id']))
    $link = get_page_link($atts['id']);

  switch($key) {
    case 'option':
      $func = 'ot_get_' . $key;
      $id = $func($value);
      $link = get_page_link( $id );
      break;
    case 'post':
      $link = get_permalink( $value );
      break;
    case 'page':
      $link = get_page_link( $value );
      break;
  }

  if(in_array($key, get_taxonomies() )) {
    $link = get_term_link( (int) $value, $key );
  }

  if($atts['modal'] || !is_null($atts['modal']) || !empty($atts['modal'])) {
    $data = 'data-toggle="modal" data-target="#'. $atts['modal'] .'"';
    $modal =<<<MODAL
    <!-- Modal -->
    <div class="modal fade" id="{$atts['modal']}" tabindex="-1" role="dialog" aria-labelledby="{$atts['modal']}Label">
      <div class="modal-dialog" role="document">
        <div class="modal-content">

        </div>
      </div>
    </div>
MODAL;
  }

  if(!$atts['text'] || is_null($atts['text']) || empty($atts['text']))
    return $link;
  return '<a href="' . $link . '" ' . $data . '>' . $atts['text'] . '</a>' . $modal;
}
add_shortcode( '~', array($this, 'generate_wp_link'));

function ajax_change_template($template) {
  global $wp;
  if (!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest') {
    return locate_template(array('ajax.php'));
  }
  else {
    return $template;
  }
}
add_filter('template_include', 'ajax_change_template');