public function __construct($file = '', $version = '1.0.0')
  {
     add_action('init', array($this, 'form_submission'), 10, 0);
  }

  public function form_submission()
  {
    global $error;

    $error = new WP_error();

    // Is this the correct way to submit the form??
    if(isset($_POST['submit']) && $_POST['action'] == 'fb_events_add')
    {
      // Do some basic validation, required fields below
      $required = array('name', 'details', 'location', 'start_date', 'start_time');

      // If is admin area, then also require 'user_id'
      if(is_admin())
        $required[] = 'user_id';

      foreach($required as $field)
      {
        if(empty($_POST[$field]))
          $error->add('field', str_replace("_", " ", ucwords($field)) . ' field is required');
      }

      // Form validation has passed
      if(!is_wp_error($error))
      {
        // Manual upload if 'image' field is set
        if(!empty($_POST['image']))
        {
          if(!function_exists('wp_handle_upload'))
            require_once(ABSPATH . 'wp-admin/includes/file.php');

          $uploaded_image = $_FILES['file'];
          $upload_overrides = array('test_form' => false);

          add_filter('upload_dir', array($this, 'fbe_upload_dir'));
          // Set upload_dir to /wp-content/uploads/images/
          $upload = wp_upload_dir();
          remove_filter('upload_dir', array($this, 'fbe_upload_dir'));

          $movefile = wp_handle_upload($uploaded_image, $upload_overrides);

          if($movefile && !isset($movefile['error']))
          {
            // If successfully moved, set location for inserting to database
            $image = "images/" . basename($uploaded_flyer);
          }
          else
          {
            // Move failed, add error
            $error->add('file', 'There was an error: ' . $movefile['error']);
          }
        }
        // Uploading using WP Media in admin area
        elseif(!empty($_POST['image_url']))
        {
          $image = str_replace(site_url() . '/wp-content/', '', $_POST['image_url']);
        }
        // If non of the above, the image_url_dropdown (an array of the 'uploads/images' folder) should be used
        else
        {
          $image = "images/" . $_POST['image_url_dropdown'];
        }

        // If still no errors, continue processing the form
        if(!is_wp_error($error))
        {
          // Are we adding a new entry or editing an existing entry
          if(isset($_GET['action']) && $_GET['action'] == 'edit')
          {
            // If editing, make sure the current logged in user owns the current event
            if(get_current_user_id() != $_POST['user_id'])
            {
              wp_die('You do not have permission to update this event.');
            }
            else
            {
              // Update the database
              $result = $this->db->update(
                $this->fb_events_table,
                array(
                  'name'        => sanitize_text_field($_POST['name']),
                  'slug'        => $this->get_slug($_POST['name']),
                  'details'     => esc_textarea($_POST['details']),
                  'location'    => sanitize_text_field($_POST['location']),
                  'start_date'  => $this->date_to_mysql($_POST['start_date']),
                  'end_date'    => $this->date_to_mysql($_POST['end_date']),
                  'start_time'  => $_POST['start_time'],
                  'end_time'    => $_POST['end_time'],
                  'image'       => $image,
                  'comments'    => $_POST['comments'],
                  'featured'    => $_POST['featured'],
                  'user_id'     => get_current_user_id()
                ),
                array('id' => $_GET['event'])
              );
            }
          }
          else
          {
            // 'edit' is not set, so we must be inserting a new entry
            $result = $this->db->insert(
              $this->fb_events_table,
              array(
                'name'        => sanitize_text_field($_POST['name']),
                'slug'        => $this->get_slug($_POST['name']),
                'details'     => esc_textarea($_POST['details']),
                'location'    => sanitize_text_field($_POST['location']),
                'start_date'  => $this->date_to_mysql($_POST['start_date']),
                'end_date'    => $this->date_to_mysql($_POST['end_date']),
                'start_time'  => $_POST['start_time'],
                'end_time'    => $_POST['end_time'],
                'image'       => $image,
                'comments'    => $_POST['comments'],
                'featured'    => $_POST['featured'],
                'user_id'     => $_POST['user_id']
              ),
              array('%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%d', '%d', '%d')
            );

            // If has been successfully inserted set success message and unset requests.
            if($result > 0)
            {
              $success = "Thank you, the event has been " . (isset($_GET['action']) ? "updated" : "added");
              unset($_GET['action']);
              $_POST = [];
            }
            else
            {
              // There was an error, add it to WP_Error
              $error = "An unknown error has occoured";
              $error->add('file', 'ERROR: ' . $this->db->print_error());
            }
          }
        }
        else
        {
          // If there was an error uploading images
          echo "<p>" . $error->get_error_message() . "</p>";
        }
      }
      else
      {
        // If form validation failed loop through errors
        foreach($error->get_error_messages() as $msg)
        {
          echo "<div class=\"error\"><p>{$msg}</p></div>";
        }
      }
    }
  }