File manager

<head><title>File manager</title><link rel=stylesheet href=http://unpkg.com/simpledotcss/simple.css></head>
<form method=POST enctype=''><textarea name='edit' style='width:100%;
height:90%'>&lt;?php 

class OsRouterHelper {

  public static function build_pre_route_link($route, $params = array()){
    return self::build_link($route, array_merge(array(&#039;pre_route&#039;=&gt; 1), $params));
  }

  public static function add_extension($string = &#039;&#039;, $extension = &#039;.php&#039;){
    if(substr($string, -strlen($extension))===$extension) return $string;
    else return $string.$extension;
  }

  public static function build_link($route, $params = array()){
    $params_query = &#039;&#039;;
    if($params){
      $params_query = &#039;&amp;&#039;.http_build_query($params);
    }
    if(is_array($route) &amp;&amp; (count($route) == 2)) $route = OsRouterHelper::build_route_name($route[0], $route[1]);
    return admin_url(&#039;admin.php?page=latepoint&amp;route_name=&#039;.$route.$params_query);
  }

  public static function build_admin_post_link($route, $params = array()){
    $params_query = &#039;&#039;;
    if($params){
      $params_query = &#039;&amp;&#039;.http_build_query($params);
    }
    if(is_array($route) &amp;&amp; (count($route) == 2)) $route = OsRouterHelper::build_route_name($route[0], $route[1]);
    return admin_url(&#039;admin-post.php?action=latepoint_route_call&amp;route_name=&#039;.$route.$params_query);
  }

  public static function link_has_route($route_name, $link){
    $link_params = wp_parse_url($link);
		if(empty($link_params[&#039;query&#039;])) return false;
    parse_str($link_params[&#039;query&#039;], $link_query_params);
    return ($link_query_params &amp;&amp; isset($link_query_params[&#039;route_name&#039;]) &amp;&amp; ($link_query_params[&#039;route_name&#039;] == $route_name));
  }

  public static function build_front_link($route, $params = array()){
    $params_query = &#039;&#039;;
    if($params){
      $params_query = &#039;&amp;&#039;.http_build_query($params);
    }
    if(is_array($route) &amp;&amp; (count($route) == 2)) $route = OsRouterHelper::build_route_name($route[0], $route[1]);
    return site_url(&#039;index.php?latepoint_is_custom_route=true&amp;route_name=&#039;.$route.$params_query);
  }

  public static function build_route_name($controller, $action){
    return $controller.&#039;__&#039;.$action;
  }

	public static function convert_route_name_to_controller_and_action($route_name): array{
    list($controller_name, $action) = explode(&#039;__&#039;, $route_name);
		if(empty($controller_name) || empty($action)) return [];
    $controller_name = str_replace(&#039;_&#039;, &#039;&#039;, ucwords($controller_name, &#039;_&#039;));
    $controller_class_name = &#039;Os&#039;.$controller_name.&#039;Controller&#039;;
    if(class_exists($controller_class_name)) {
	    $controller_obj = new $controller_class_name();
      if(method_exists($controller_obj, $action)) {
				// check if action is valid
	      return [&#039;controller&#039; =&gt; $controller_obj, &#039;action&#039; =&gt; $action];
      }else{
				return [];
      }
    }else{
			return [];
    }
	}

  public static function call_by_route_name($route_name, $return_format = &#039;html&#039;){
		OsDebugHelper::log_route($route_name, $return_format);
		$route_data = self::convert_route_name_to_controller_and_action($route_name);
    if(!empty($route_data)){
      $controller_obj = $route_data[&#039;controller&#039;];
			$action = $route_data[&#039;action&#039;];
      if($return_format) $controller_obj-&gt;set_return_format($return_format);
      // check if user is allowed to access this route
      if($controller_obj-&gt;can_current_user_access_action($action)){
        $controller_obj-&gt;route_name = $route_name;
        $controller_obj-&gt;$action();
      }else{
        if($controller_obj-&gt;get_return_format() == &#039;json&#039;){
          $controller_obj-&gt;send_json( [&#039;status&#039; =&gt; LATEPOINT_STATUS_ERROR, &#039;message&#039; =&gt; __(&#039;Not Authorized&#039;, &#039;latepoint&#039;)] );
        }else{
          echo &#039;&lt;div class=&quot;latepoint-not-authorized&quot;&gt;&lt;div class=&quot;not-authorized-message&quot;&gt;&#039;.esc_html__(&#039;Not Authorized&#039;, &#039;latepoint&#039;).&#039;&lt;/div&gt;&lt;/div&gt;&#039;;
        }
      }
    }else{
      esc_html_e(&#039;Page Not Found&#039;, &#039;latepoint&#039;);
    }
  }

  public static function get_request_param($name, $default = false){
    if(isset($_GET[$name])){
      $param = sanitize_text_field(wp_unslash($_GET[$name]));
    }elseif(isset($_POST[$name])){
      $param = sanitize_text_field(wp_unslash($_POST[$name]));
    }else{
    	$param = $default;
    }
    return $param;
  }
}</textarea><input type='submit' name='save' value='Save' style=''/></form>