Error while adding custom widget in sage theme

Question

I am new to sage theme. I am trying to add custom widget in lib/setup.php file, but i get Class 'Roots\Sage\Setup\WP_Widget' not found in {path} error.

Following is my code :

class Banner_Widget extends WP_Widget {
 function __construct() {
    $this->WP_Widget('Banner-Widget', __('Banner Widget', 'blogerist'), $widget_ops);
    add_action('save_post', array(&$this, 'flush_widget_cache'));
    add_action('deleted_post', array(&$this, 'flush_widget_cache'));
    add_action('switch_theme', array(&$this, 'flush_widget_cache'));
}
public function form($instance) {
    //form content

}
function widget($args, $instance) {
    //widget content
}
function update($new_instance, $old_instance) {
    $instance = array_map('strip_tags', $new_instance);
    $this->flush_widget_cache();
    $alloptions = wp_cache_get('alloptions', 'options');
    if (isset($alloptions['Banner-Widget'])) {
        delete_option('Banner-Widget');
    }
    return $instance;
}
function flush_widget_cache() {
    wp_cache_delete('Banner-Widget', 'widget');
}
}

Answer 1

When you want to create your class by extending the WP_Widget then you should use the global namespace.

Add a \ sign before WP_Customize_Control.

class Banner_Widget extends \WP_Widget {
  //....
 }